Patent Publication Number: US-2022235748-A1

Title: Electromagnetic Energy Momentum Thruster Using Tapered Cavity Resonator Evanescent Modes

Description:
PRIORITY 
     This patent application is a continuation application of U.S. patent application Ser. No. 16/271,275, filed Feb. 8, 2019, entitled, “ELECTROMAGNETIC ENERGY MOMENTUM THRUSTER USING TAPERED CAVITY RESONATOR EVANESCENT MODES,” and naming Kyle Bernard Flanagan and Peter Clinton Dohm as inventors, which claims priority from provisional U.S. patent application No. 62/629,106, filed Feb. 11, 2018, entitled, “ELECTROMAGNETIC ENERGY MOMENTUM THRUSTER USING TAPERED CAVITY RESONATOR EVANESCENT MODES,” and naming Kyle Bernard Flanagan and Peter Clinton Dohm as inventors. The disclosures of both patent applications are incorporated herein, in their entireties, by reference. 
    
    
     BACKGROUND 
     An electromagnetic energy momentum thruster, also known as a radio frequency (RF) resonant cavity thruster or an EmDrive, is an electromagnetic thruster comprising a cavity resonator and an electromagnetic radiation source which produces a thrust from an electromagnetic field inside the cavity resonator. Such electromagnetic energy momentum thrusters provide direct conversion of electrical energy to thrust without the use of a propellant. 
     Eagleworks Laboratories at NASA&#39;s Johnson Space Center led by Dr. Harold “Sonny” White has successfully tested an electromagnetic energy momentum thruster in a vacuum. Thrust measurement test results of the EmDrive were presented at the 50 th  AIAA/ASME/SAE/ASEE Joint Propulsion Conference in Cleveland, Ohio on Jul. 28-30, 2014, and were published in AIAA Journal of Propulsion and Power in July 2017 in an article entitled, “Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum”. 
     SUMMARY 
     Although electromagnetic energy momentum thrusters have been developed, many such devices known the inventors exhibit suboptimal propulsion efficiencies and produce low thrust. The suboptimal propulsion efficiencies of previously available electromagnetic energy momentum thrusters may be attributed to the inclusion of extraneous elements within the cavity resonator, suboptimal geometric designs, and insufficient treatment of superconducting materials on the interior surface of the cavity resonator. These limitations of previously available electromagnetic energy momentum thrusters reduce the transmission of electromagnetic energy due to absorption losses, and exhibit lower electromagnetic energy densities, electromagnetic momentum asymmetries, quality factors, propulsion efficiencies, and thrust capabilities. 
     Provided herein are electromagnetic energy momentum thrusters which exhibit high propulsion efficiencies and are configured to produce high thrust. In some embodiments, the shape of the cavity resonators provided herein enable an optimized RF tuning quality factor, and form large electric and magnetic field asymmetries. In some embodiments, the cavity resonators are designed with specific equations and boundary conditions which enable more efficient propulsion. 
     In some embodiments, the electromagnetic energy momentum thrusters provided herein comprise a cavity resonator, which is configured for highly efficient conversion of electrical energy to thrust or momentum. In some embodiments, at least one of a lack of extraneous interior elements, the evacuation of the cavity resonator below a critical pressure threshold, the cooling of the cavity resonator below a critical temperature threshold, and a superconductive coating within the cavity resonator enables such highly efficient propulsion. In some embodiments, the superconductive material within the cavity resonator is optimized for high quality factor. In some embodiments, the highly directional electromagnetic energy momentum tensor provides a highly directional general relativistic metric tensor and a corresponding free fall acceleration which is an equal and opposite reaction to an action of thrust from the highly asymmetric electromagnetic radiation pressure. 
     Various embodiments include an electromagnetic energy momentum thruster comprising: a cavity resonator forming a cavity having a base interior surface and a tapered interior surface, the tapered interior surface converging to an apex point; and an electromagnetic radiation source in communication with the cavity resonator, the electromagnetic radiation source configured to emit an electromagnetic wave having a frequency between about 1.0 MHz to about 1000 THz into the cavity resonator. 
     In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at least about 10{circumflex over ( )}0 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at most about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}1 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}9 MHz, or between about 10{circumflex over ( )}8 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of about 10{circumflex over ( )}0 MHz, about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}2 MHz, about 10{circumflex over ( )}3 MHz, about 10{circumflex over ( )}4 MHz, about 10{circumflex over ( )}5 MHz, about 10{circumflex over ( )}6 MHz, about 10{circumflex over ( )}7 MHz, about 10{circumflex over ( )}8 MHz, or about 10{circumflex over ( )}9 MHz, including increments therein. 
     In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, the base interior surface, the asymptotic field amplitude being at, or adjacent to, one or both the tapered interior surface and the apex point. In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, one or both the tapered interior surface and the apex point, and the asymptotic field amplitude being at, or adjacent to, the base interior surface. 
     In some embodiments, the cavity includes an overall interior surface that includes the base and tapered interior surfaces, substantially the entire overall interior surface being electrically conductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}3. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}4, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, or between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}3, about 10{circumflex over ( )}4, about 10{circumflex over ( )}5, about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, or about 10{circumflex over ( )}9, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. 
     In some embodiments, the cavity includes an overall interior surface that includes the base and tapered interior surfaces, substantially the entire overall interior surface being superconductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}6. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}15, or between about 10{circumflex over ( )}14 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, about 10{circumflex over ( )}9, about 10{circumflex over ( )}10, about 10{circumflex over ( )}11, about 10{circumflex over ( )}12, about 10{circumflex over ( )}13, about 10{circumflex over ( )}14, or about 10{circumflex over ( )}15, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , T 12 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity is empty. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at least about 10{circumflex over ( )}−24 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at most about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−21 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−24 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−21 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−18 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−15 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−12 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−9 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−6 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−3 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−3 Torr to about 10{circumflex over ( )}3 Torr, or between about 1.0 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr, including increments therein. 
     In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at least about 10{circumflex over ( )}−3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at most about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 1 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 5 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 25 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 50 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 100 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 200 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 300 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 1 Kelvin to about 5 Kelvin, between about 1 Kelvin to about 10 Kelvin, between about 1 Kelvin to about 25 Kelvin, between about 1 Kelvin to about 50 Kelvin, between about 1 Kelvin to about 100 Kelvin, between about 1 Kelvin to about 200 Kelvin, between about 1 Kelvin to about 300 Kelvin, between about 1 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 5 Kelvin to about 10 Kelvin, between about 5 Kelvin to about 25 Kelvin, between about 5 Kelvin to about 50 Kelvin, between about 5 Kelvin to about 100 Kelvin, between about 5 Kelvin to about 200 Kelvin, between about 5 Kelvin to about 300 Kelvin, between about 5 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 10 Kelvin to about 25 Kelvin, between about 10 Kelvin to about 50 Kelvin, between about 10 Kelvin to about 100 Kelvin, between about 10 Kelvin to about 200 Kelvin, between about 10 Kelvin to about 300 Kelvin, between about 10 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 25 Kelvin to about 50 Kelvin, between about 25 Kelvin to about 100 Kelvin, between about 25 Kelvin to about 200 Kelvin, between about 25 Kelvin to about 300 Kelvin, between about 25 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 50 Kelvin to about 100 Kelvin, between about 50 Kelvin to about 200 Kelvin, between about 50 Kelvin to about 300 Kelvin, between about 50 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 100 Kelvin to about 200 Kelvin, between about 100 Kelvin to about 300 Kelvin, between about 100 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 200 Kelvin to about 300 Kelvin, between about 200 Kelvin to about 10{circumflex over ( )}3 Kelvin, or between about 300 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin, including increments therein. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. 
     In some embodiments, the electromagnetic radiation source is located inside the cavity at, or adjacent to, a maximum field amplitude or an asymptotic field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has at least one of a width and a height of at most about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−3 meters to about 1.0 meter, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−2 meters to about 1.0 meter, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−1 meters to about 1.0 meter, between about 10{circumflex over ( )}−1 meters to about 10{circumflex over ( )}3 meters, or between about 1.0 meter to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−3 meters, about 10{circumflex over ( )}−2 meters, about 10{circumflex over ( )}−1 meters, about 1.0 meter, or about 10{circumflex over ( )}3 meters, including increments therein. 
     In some embodiments, the tapered interior surface forms an aperture angle between about 5 degrees to about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle of at least about 5 degrees. In some embodiments, the tapered interior surface forms an aperture angle of at most about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle between about 5 degrees to about 10 degrees, between about 5 degrees to about 20 degrees, between about 5 degrees to about 40 degrees, between about 5 degrees to about 60 degrees, between about 5 degrees to about 80 degrees, between about 5 degrees to about 100 degrees, between about 5 degrees to about 120 degrees, between about 5 degrees to about 140 degrees, between about 5 degrees to about 160 degrees, between about 5 degrees to about 175 degrees, between about 10 degrees to about 20 degrees, between about 10 degrees to about 40 degrees, between about 10 degrees to about 60 degrees, between about 10 degrees to about 80 degrees, between about 10 degrees to about 100 degrees, between about 10 degrees to about 120 degrees, between about 10 degrees to about 140 degrees, between about 10 degrees to about 160 degrees, between about 10 degrees to about 175 degrees, between about 20 degrees to about 40 degrees, between about 20 degrees to about 60 degrees, between about 20 degrees to about 80 degrees, between about 20 degrees to about 100 degrees, between about 20 degrees to about 120 degrees, between about 20 degrees to about 140 degrees, between about 20 degrees to about 160 degrees, between about 20 degrees to about 175 degrees, between about 40 degrees to about 60 degrees, between about 40 degrees to about 80 degrees, between about 40 degrees to about 100 degrees, between about 40 degrees to about 120 degrees, between about 40 degrees to about 140 degrees, between about 40 degrees to about 160 degrees, between about 40 degrees to about 175 degrees, between about 60 degrees to about 80 degrees, between about 60 degrees to about 100 degrees, between about 60 degrees to about 120 degrees, between about 60 degrees to about 140 degrees, between about 60 degrees to about 160 degrees, between about 60 degrees to about 175 degrees, between about 80 degrees to about 100 degrees, between about 80 degrees to about 120 degrees, between about 80 degrees to about 140 degrees, between about 80 degrees to about 160 degrees, between about 80 degrees to about 175 degrees, between about 100 degrees to about 120 degrees, between about 100 degrees to about 140 degrees, between about 100 degrees to about 160 degrees, between about 100 degrees to about 175 degrees, between about 120 degrees to about 140 degrees, between about 120 degrees to about 160 degrees, between about 120 degrees to about 175 degrees, between about 140 degrees to about 160 degrees, between about 140 degrees to about 175 degrees, or between about 160 degrees to about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle of about 5 degrees, about 10 degrees, about 20 degrees, about 40 degrees, about 60 degrees, about 80 degrees, about 100 degrees, about 120 degrees, about 140 degrees, about 160 degrees, or about 175 degrees, including increments therein. 
     In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has a wall with a wall thickness of at most about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−5 meters to about 1.0 meter, between about 10{circumflex over ( )}−4 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−4 meters to about 1.0 meter, or between about 10{circumflex over ( )}−3 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−5 meters, about 10{circumflex over ( )}−4 meters, about 10{circumflex over ( )}−3 meters, or about 1.0 meter, including increments therein. 
     In some embodiments, the base interior surface is substantially elliptical. In some embodiments, the base interior surface is substantially circular. In some embodiments, the base interior surface is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or both the tapered interior surface and the apex point, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Another embodiment includes an electromagnetic energy momentum thruster comprising: a cavity resonator forming a cavity having a base interior surface, a tapered interior surface, and a truncated interior surface opposing the base interior surface, the tapered interior surface being between the base and truncated interior surfaces; and an electromagnetic radiation source in communication with the cavity resonator, the electromagnetic radiation source configured to emit an electromagnetic wave having a frequency between about 1.0 MHz to about 1000 THz into the cavity resonator, the electromagnetic radiation source configured to produce the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. 
     In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at least about 10{circumflex over ( )}0 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at most about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}1 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}9 MHz, or between about 10{circumflex over ( )}8 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}2 MHz, about 10{circumflex over ( )}3 MHz, about 10{circumflex over ( )}4 MHz, about 10{circumflex over ( )}5 MHz, about 10{circumflex over ( )}6 MHz, about 10{circumflex over ( )}7 MHz, about 10{circumflex over ( )}8 MHz, or about 10{circumflex over ( )}9 MHz, including increments therein. 
     In some embodiments, the maximum field amplitude is at, or adjacent to, the base interior surface, and the asymptotic field amplitude is at, or adjacent to, one or both the tapered interior surface and the truncated interior surface. In some embodiments, the maximum field amplitude is at, or adjacent to, one or both the tapered interior surface and the truncated interior surface, and the asymptotic field amplitude is at, or adjacent to, the base interior surface. 
     In some embodiments, the cavity includes an overall interior surface that includes the base, tapered, and truncated interior surfaces, substantially the entire overall interior surface being electrically conductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}3. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}4, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}5 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, or between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}3, about 10{circumflex over ( )}4, about 10{circumflex over ( )}5, about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, or about 10{circumflex over ( )}9, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. 
     In some embodiments, the cavity includes an overall interior surface that includes the base, tapered, and/or truncated interior surfaces, substantially the entire overall interior surface being superconductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}6. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}15, or between about 10{circumflex over ( )}14 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, about 10{circumflex over ( )}9, about 10{circumflex over ( )}10, about 10{circumflex over ( )}11, about 10{circumflex over ( )}12, about 10{circumflex over ( )}13, about 10{circumflex over ( )}14, or about 10{circumflex over ( )}15, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity is empty. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at least about 10{circumflex over ( )}−24 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at most about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−21 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−24 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−21 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−18 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−15 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−12 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−9 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−6 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−3 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−3 Torr to about 10{circumflex over ( )}3 Torr, or between about 1.0 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr, including increments therein. 
     In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at least about 10{circumflex over ( )}−3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at most about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 1 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 5 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 25 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 50 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 100 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 200 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 300 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 1 Kelvin to about 5 Kelvin, between about 1 Kelvin to about 10 Kelvin, between about 1 Kelvin to about 25 Kelvin, between about 1 Kelvin to about 50 Kelvin, between about 1 Kelvin to about 100 Kelvin, between about 1 Kelvin to about 200 Kelvin, between about 1 Kelvin to about 300 Kelvin, between about 1 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 5 Kelvin to about 10 Kelvin, between about 5 Kelvin to about 25 Kelvin, between about 5 Kelvin to about 50 Kelvin, between about 5 Kelvin to about 100 Kelvin, between about 5 Kelvin to about 200 Kelvin, between about 5 Kelvin to about 300 Kelvin, between about 5 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 10 Kelvin to about 25 Kelvin, between about 10 Kelvin to about 50 Kelvin, between about 10 Kelvin to about 100 Kelvin, between about 10 Kelvin to about 200 Kelvin, between about 10 Kelvin to about 300 Kelvin, between about 10 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 25 Kelvin to about 50 Kelvin, between about 25 Kelvin to about 100 Kelvin, between about 25 Kelvin to about 200 Kelvin, between about 25 Kelvin to about 300 Kelvin, between about 25 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 50 Kelvin to about 100 Kelvin, between about 50 Kelvin to about 200 Kelvin, between about 50 Kelvin to about 300 Kelvin, between about 50 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 100 Kelvin to about 200 Kelvin, between about 100 Kelvin to about 300 Kelvin, between about 100 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 200 Kelvin to about 300 Kelvin, between about 200 Kelvin to about 10{circumflex over ( )}3 Kelvin, or between about 300 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin, including increments therein. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. 
     In some embodiments, the electromagnetic radiation source is located inside the cavity at, or adjacent to, a maximum field amplitude or an asymptotic field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has at least one of a width and a height of at most about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−3 meters to about 1.0 meter, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−2 meters to about 1.0 meter, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−1 meters to about 1.0 meter, between about 10{circumflex over ( )}−1 meters to about 10{circumflex over ( )}3 meters, or between about 1.0 meter to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−3 meters, about 10{circumflex over ( )}−2 meters, about 10{circumflex over ( )}−1 meters, about 1.0 meter, or about 10{circumflex over ( )}3 meters, including increments therein. 
     In some embodiments, the tapered interior surface forms an aperture angle between about 5 degrees to about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle of at least about 5 degrees. In some embodiments, the tapered interior surface forms an aperture angle of at most about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle between about 5 degrees to about 10 degrees, between about 5 degrees to about 20 degrees, between about 5 degrees to about 40 degrees, between about 5 degrees to about 60 degrees, between about 5 degrees to about 80 degrees, between about 5 degrees to about 100 degrees, between about 5 degrees to about 120 degrees, between about 5 degrees to about 140 degrees, between about 5 degrees to about 160 degrees, between about 5 degrees to about 175 degrees, between about 10 degrees to about 20 degrees, between about 10 degrees to about 40 degrees, between about 10 degrees to about 60 degrees, between about 10 degrees to about 80 degrees, between about 10 degrees to about 100 degrees, between about 10 degrees to about 120 degrees, between about 10 degrees to about 140 degrees, between about 10 degrees to about 160 degrees, between about 10 degrees to about 175 degrees, between about 20 degrees to about 40 degrees, between about 20 degrees to about 60 degrees, between about 20 degrees to about 80 degrees, between about 20 degrees to about 100 degrees, between about 20 degrees to about 120 degrees, between about 20 degrees to about 140 degrees, between about 20 degrees to about 160 degrees, between about 20 degrees to about 175 degrees, between about 40 degrees to about 60 degrees, between about 40 degrees to about 80 degrees, between about 40 degrees to about 100 degrees, between about 40 degrees to about 120 degrees, between about 40 degrees to about 140 degrees, between about 40 degrees to about 160 degrees, between about 40 degrees to about 175 degrees, between about 60 degrees to about 80 degrees, between about 60 degrees to about 100 degrees, between about 60 degrees to about 120 degrees, between about 60 degrees to about 140 degrees, between about 60 degrees to about 160 degrees, between about 60 degrees to about 175 degrees, between about 80 degrees to about 100 degrees, between about 80 degrees to about 120 degrees, between about 80 degrees to about 140 degrees, between about 80 degrees to about 160 degrees, between about 80 degrees to about 175 degrees, between about 100 degrees to about 120 degrees, between about 100 degrees to about 140 degrees, between about 100 degrees to about 160 degrees, between about 100 degrees to about 175 degrees, between about 120 degrees to about 140 degrees, between about 120 degrees to about 160 degrees, between about 120 degrees to about 175 degrees, between about 140 degrees to about 160 degrees, between about 140 degrees to about 175 degrees, between or about 160 degrees to about 175 degrees. In some embodiments, the tapered interior surface forms an aperture angle of about 5 degrees, about 10 degrees, about 20 degrees, about 40 degrees, about 60 degrees, about 80 degrees, about 100 degrees, about 120 degrees, about 140 degrees, about 160 degrees, or about 175 degrees, including increments therein. 
     In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has a wall with a wall thickness of at most about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−5 meters to about 1.0 meter, between about 10{circumflex over ( )}−4 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−4 meters to about 1.0 meter, or between about 10{circumflex over ( )}−3 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−5 meters, about 10{circumflex over ( )}−4 meters, about 10{circumflex over ( )}−3 meters, or about 1.0 meter, including increments therein. 
     In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity is substantially elliptical. In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity is substantially circular. In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or both the tapered interior surface and the truncated interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Another embodiment includes an electromagnetic energy momentum thruster comprising: a cavity resonator forming a pyramidal cavity having a base interior surface and at least three tapered interior surfaces, the tapered interior surfaces converging to an apex point; and an electromagnetic radiation source in communication with the cavity resonator, the electromagnetic radiation source configured to emit an electromagnetic wave having a frequency between about 1.0 MHz to about 1000 THz into the cavity resonator. 
     In some embodiments, the electromagnetic radiation source configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source configured to emit an electromagnetic wave into the cavity resonator having a frequency of at least about 10{circumflex over ( )}0 MHz. In some embodiments, the electromagnetic radiation source configured to emit an electromagnetic wave into the cavity resonator having a frequency of at most about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}1 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}9 MHz, or between about 10{circumflex over ( )}8 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source configured to emit an electromagnetic wave into the cavity resonator having a frequency of about 10{circumflex over ( )}0 MHz, about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}2 MHz, about 10{circumflex over ( )}3 MHz, about 10{circumflex over ( )}4 MHz, about 10{circumflex over ( )}5 MHz, about 10{circumflex over ( )}6 MHz, about 10{circumflex over ( )}7 MHz, about 10{circumflex over ( )}8 MHz, or about 10{circumflex over ( )}9 MHz, including increments therein. 
     In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, the base interior surface, the asymptotic field amplitude being at, or adjacent to, one or more of the at least three tapered interior surfaces and the apex point. In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, one or more of the at least three tapered interior surfaces and the apex point, and the asymptotic field amplitude being at, or adjacent to, the base interior surface. 
     In some embodiments, the cavity includes an overall interior surface that includes the base and tapered interior surfaces, substantially the entire overall interior surface being electrically conductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}3. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}4, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, or between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}3, about 10{circumflex over ( )}4, about 10{circumflex over ( )}5, about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, or about 10{circumflex over ( )}9, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. 
     In some embodiments, the cavity includes an overall interior surface that includes the base and tapered interior surfaces, substantially the entire overall interior surface being superconductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}6. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}15, or between about 10{circumflex over ( )}14 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, about 10{circumflex over ( )}9, about 10{circumflex over ( )}10, about 10{circumflex over ( )}11, about 10{circumflex over ( )}12, about 10{circumflex over ( )}13, about 10{circumflex over ( )}14, or about 10{circumflex over ( )}15, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity is empty. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at least about 10{circumflex over ( )}−24 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at most about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−21 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−24 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−21 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−18 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−15 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−12 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−9 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−6 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−3 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−3 Torr to about 10{circumflex over ( )}3 Torr, or between about 1.0 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr, including increments therein. 
     In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at least about 10{circumflex over ( )}−3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at most about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 1 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 5 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 25 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 50 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 100 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 200 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 300 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 1 Kelvin to about 5 Kelvin, between about 1 Kelvin to about 10 Kelvin, between about 1 Kelvin to about 25 Kelvin, between about 1 Kelvin to about 50 Kelvin, between about 1 Kelvin to about 100 Kelvin, between about 1 Kelvin to about 200 Kelvin, between about 1 Kelvin to about 300 Kelvin, between about 1 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 5 Kelvin to about 10 Kelvin, between about 5 Kelvin to about 25 Kelvin, between about 5 Kelvin to about 50 Kelvin, between about 5 Kelvin to about 100 Kelvin, between about 5 Kelvin to about 200 Kelvin, between about 5 Kelvin to about 300 Kelvin, between about 5 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 10 Kelvin to about 25 Kelvin, between about 10 Kelvin to about 50 Kelvin, between about 10 Kelvin to about 100 Kelvin, between about 10 Kelvin to about 200 Kelvin, between about 10 Kelvin to about 300 Kelvin, between about 10 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 25 Kelvin to about 50 Kelvin, between about 25 Kelvin to about 100 Kelvin, between about 25 Kelvin to about 200 Kelvin, between about 25 Kelvin to about 300 Kelvin, between about 25 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 50 Kelvin to about 100 Kelvin, between about 50 Kelvin to about 200 Kelvin, between about 50 Kelvin to about 300 Kelvin, between about 50 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 100 Kelvin to about 200 Kelvin, between about 100 Kelvin to about 300 Kelvin, between about 100 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 200 Kelvin to about 300 Kelvin, between about 200 Kelvin to about 10{circumflex over ( )}3 Kelvin, or between about 300 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin, including increments therein. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. 
     In some embodiments, the electromagnetic radiation source is located inside the cavity at, or adjacent to, a maximum field amplitude or an asymptotic field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has at least one of a width and a height of at most about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−3 meters to about 1.0 meter, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−2 meters to about 1.0 meter, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−1 meters to about 1.0 meter, between about 10{circumflex over ( )}−1 meters to about 10{circumflex over ( )}3 meters, or between about 1.0 meter to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−3 meters, about 10{circumflex over ( )}−2 meters, about 10{circumflex over ( )}−1 meters, about 1.0 meter, or about 10{circumflex over ( )}3 meters, including increments therein. 
     In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle between about 5 degrees to about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of at least about 5 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of at most about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle between about 5 degrees to about 10 degrees, between about 5 degrees to about 20 degrees, between about 5 degrees to about 40 degrees, between about 5 degrees to about 60 degrees, between about 5 degrees to about 80 degrees, between about 5 degrees to about 100 degrees, between about 5 degrees to about 120 degrees, between about 5 degrees to about 140 degrees, between about 5 degrees to about 160 degrees, between about 5 degrees to about 175 degrees, between about 10 degrees to about 20 degrees, between about 10 degrees to about 40 degrees, between about 10 degrees to about 60 degrees, between about 10 degrees to about 80 degrees, between about 10 degrees to about 100 degrees, between about 10 degrees to about 120 degrees, between about 10 degrees to about 140 degrees, between about 10 degrees to about 160 degrees, between about 10 degrees to about 175 degrees, between about 20 degrees to about 40 degrees, between about 20 degrees to about 60 degrees, between about 20 degrees to about 80 degrees, between about 20 degrees to about 100 degrees, between about 20 degrees to about 120 degrees, between about 20 degrees to about 140 degrees, between about 20 degrees to about 160 degrees, between about 20 degrees to about 175 degrees, between about 40 degrees to about 60 degrees, between about 40 degrees to about 80 degrees, between about 40 degrees to about 100 degrees, between about 40 degrees to about 120 degrees, between about 40 degrees to about 140 degrees, between about 40 degrees to about 160 degrees, between about 40 degrees to about 175 degrees, between about 60 degrees to about 80 degrees, between about 60 degrees to about 100 degrees, between about 60 degrees to about 120 degrees, between about 60 degrees to about 140 degrees, between about 60 degrees to about 160 degrees, between about 60 degrees to about 175 degrees, between about 80 degrees to about 100 degrees, between about 80 degrees to about 120 degrees, between about 80 degrees to about 140 degrees, between about 80 degrees to about 160 degrees, between about 80 degrees to about 175 degrees, between about 100 degrees to about 120 degrees, between about 100 degrees to about 140 degrees, between about 100 degrees to about 160 degrees, between about 100 degrees to about 175 degrees, between about 120 degrees to about 140 degrees, between about 120 degrees to about 160 degrees, between about 120 degrees to about 175 degrees, between about 140 degrees to about 160 degrees, between about 140 degrees to about 175 degrees, or between about 160 degrees to about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of about 5 degrees, about 10 degrees, about 20 degrees, about 40 degrees, about 60 degrees, about 80 degrees, about 100 degrees, about 120 degrees, about 140 degrees, about 160 degrees, or about 175 degrees, including increments therein. 
     In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has a wall with a wall thickness of at most about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−5 meters to about 1.0 meter, between about 10{circumflex over ( )}−4 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−4 meters to about 1.0 meter, or between about 10{circumflex over ( )}−3 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−5 meters, about 10{circumflex over ( )}−4 meters, about 10{circumflex over ( )}−3 meters, or about 1.0 meter, including increments therein. 
     In some embodiments, the base interior surface of the cavity comprises 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 sides. In some embodiments, the base interior surface of the cavity is substantially equilateral. In some embodiments, the base interior surface is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or more of the at least three tapered interior surfaces and the apex point, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Another embodiment includes an electromagnetic energy momentum thruster comprising: a cavity resonator forming a pyramidal cavity having a base interior surface, at least three tapered interior surfaces, and a truncated interior surface opposing the base interior surface, the tapered interior surfaces being between the base and truncated interior surfaces; and an electromagnetic radiation source in communication with the cavity resonator, the electromagnetic radiation source configured to emit an electromagnetic wave having a frequency between about 1.0 MHz to about 1000 THz into the cavity resonator. 
     In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at least about 10{circumflex over ( )}0 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of at most about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}1 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}2 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}3 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}2 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}4 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}3 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}5 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}4 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}6 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}5 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}7 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}6 MHz to about 10{circumflex over ( )}9 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}8 MHz, between about 10{circumflex over ( )}7 MHz to about 10{circumflex over ( )}9 MHz, or between about 10{circumflex over ( )}8 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the electromagnetic radiation source is configured to emit an electromagnetic wave into the cavity resonator having a frequency of about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}1 MHz, about 10{circumflex over ( )}2 MHz, about 10{circumflex over ( )}3 MHz, about 10{circumflex over ( )}4 MHz, about 10{circumflex over ( )}5 MHz, about 10{circumflex over ( )}6 MHz, about 10{circumflex over ( )}7 MHz, about 10{circumflex over ( )}8 MHz, or about 10{circumflex over ( )}9 MHz, including increments therein. 
     In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, the base interior surface, the asymptotic field amplitude being at, or adjacent to, one or more of the at least three tapered interior surfaces and the truncated interior surface. In some embodiments, the electromagnetic radiation source is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude, the maximum field amplitude being at, or adjacent to, one or more of the at least three tapered interior surfaces and the truncated interior surface, the asymptotic field amplitude being at, or adjacent to, the base interior surface. 
     In some embodiments, the cavity includes an overall interior surface that includes the base, tapered, and truncated interior surfaces, substantially the entire overall interior surface being electrically conductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}3. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}4, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}5, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}6, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}4 to about 10{circumflex over ( )}5, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}9, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}6, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}7, about 10{circumflex over ( )}4 to about 10{circumflex over ( )}8, about 10{circumflex over ( )}5 to about 10{circumflex over ( )}9, about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, or about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}3, about 10{circumflex over ( )}4, about 10{circumflex over ( )}5, about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, or about 10{circumflex over ( )}9, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. 
     In some embodiments, the cavity includes an overall interior surface that includes the base, tapered, and truncated interior surfaces, substantially the entire overall interior surface being superconductive, wherein the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of at least about 10{circumflex over ( )}6. In some embodiments, the cavity resonator has a quality factor of at most about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}7, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}8, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}7 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}9, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}8 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}10, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}9 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}11, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}10 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}12, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}11 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}13, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}12 to about 10{circumflex over ( )}15, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}14, between about 10{circumflex over ( )}13 to about 10{circumflex over ( )}15, or between about 10{circumflex over ( )}14 to about 10{circumflex over ( )}15. In some embodiments, the cavity resonator has a quality factor of about 10{circumflex over ( )}6, about 10{circumflex over ( )}7, about 10{circumflex over ( )}8, about 10{circumflex over ( )}9, about 10{circumflex over ( )}10, about 10{circumflex over ( )}11, about 10{circumflex over ( )}12, about 10{circumflex over ( )}13, about 10{circumflex over ( )}14, or about 10{circumflex over ( )}15, including increments therein. 
     In some embodiments, the overall interior surface comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity is empty. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at least about 10{circumflex over ( )}−24 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of at most about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−21 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−24 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−18 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−21 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−21 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−15 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−18 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−18 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−12 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−15 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−15 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−9 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−12 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−12 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−6 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−9 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−9 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}−3 Torr, between about 10{circumflex over ( )}−6 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−6 Torr to about 10{circumflex over ( )}3 Torr, between about 10{circumflex over ( )}−3 Torr to about 1.0 Torr, between about 10{circumflex over ( )}−3 Torr to about 10{circumflex over ( )}3 Torr, or between about 1.0 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr, including increments therein. 
     In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at least about 10{circumflex over ( )}−3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of at most about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 1 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 5 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 25 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 50 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 100 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 200 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 300 Kelvin, between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 1 Kelvin to about 5 Kelvin, between about 1 Kelvin to about 10 Kelvin, between about 1 Kelvin to about 25 Kelvin, between about 1 Kelvin to about 50 Kelvin, between about 1 Kelvin to about 100 Kelvin, between about 1 Kelvin to about 200 Kelvin, between about 1 Kelvin to about 300 Kelvin, between about 1 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 5 Kelvin to about 10 Kelvin, between about 5 Kelvin to about 25 Kelvin, between about 5 Kelvin to about 50 Kelvin, between about 5 Kelvin to about 100 Kelvin, between about 5 Kelvin to about 200 Kelvin, between about 5 Kelvin to about 300 Kelvin, between about 5 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 10 Kelvin to about 25 Kelvin, between about 10 Kelvin to about 50 Kelvin, between about 10 Kelvin to about 100 Kelvin, between about 10 Kelvin to about 200 Kelvin, between about 10 Kelvin to about 300 Kelvin, between about 10 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 25 Kelvin to about 50 Kelvin, between about 25 Kelvin to about 100 Kelvin, between about 25 Kelvin to about 200 Kelvin, between about 25 Kelvin to about 300 Kelvin, between about 25 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 50 Kelvin to about 100 Kelvin, between about 50 Kelvin to about 200 Kelvin, between about 50 Kelvin to about 300 Kelvin, between about 50 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 100 Kelvin to about 200 Kelvin, between about 100 Kelvin to about 300 Kelvin, between about 100 Kelvin to about 10{circumflex over ( )}3 Kelvin, between about 200 Kelvin to about 300 Kelvin, between about 200 Kelvin to about 10{circumflex over ( )}3 Kelvin, or between about 300 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin, including increments therein. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. 
     In some embodiments, the electromagnetic radiation source is located inside the cavity at, or adjacent to, a maximum field amplitude or an asymptotic field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has at least one of a width and a height of at most about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−2 meters, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−3 meters to about 1.0 meter, between about 10{circumflex over ( )}−3 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}−1 meters, between about 10{circumflex over ( )}−2 meters to about 1.0 meter, between about 10{circumflex over ( )}−2 meters to about 10{circumflex over ( )}3 meters, between about 10{circumflex over ( )}−1 meters to about 1.0 meter, between about 10{circumflex over ( )}−1 meters to about 10{circumflex over ( )}3 meters, or between about 1.0 meter to about 10{circumflex over ( )}3 meters. In some embodiments, the cavity has at least one of a width and a height of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−3 meters, about 10{circumflex over ( )}−2 meters, about 10{circumflex over ( )}−1 meters, about 1.0 meter, or about 10{circumflex over ( )}3 meters, including increments therein. 
     In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle between about 5 degrees to about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of at least about 5 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of at most about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle between about 5 degrees to about 10 degrees, between about 5 degrees to about 20 degrees, between about 5 degrees to about 40 degrees, between about 5 degrees to about 60 degrees, between about 5 degrees to about 80 degrees, between about 5 degrees to about 100 degrees, between about 5 degrees to about 120 degrees, between about 5 degrees to about 140 degrees, between about 5 degrees to about 160 degrees, between about 5 degrees to about 175 degrees, between about 10 degrees to about 20 degrees, between about 10 degrees to about 40 degrees, between about 10 degrees to about 60 degrees, between about 10 degrees to about 80 degrees, between about 10 degrees to about 100 degrees, between about 10 degrees to about 120 degrees, between about 10 degrees to about 140 degrees, between about 10 degrees to about 160 degrees, between about 10 degrees to about 175 degrees, between about 20 degrees to about 40 degrees, between about 20 degrees to about 60 degrees, between about 20 degrees to about 80 degrees, between about 20 degrees to about 100 degrees, between about 20 degrees to about 120 degrees, between about 20 degrees to about 140 degrees, between about 20 degrees to about 160 degrees, between about 20 degrees to about 175 degrees, between about 40 degrees to about 60 degrees, between about 40 degrees to about 80 degrees, between about 40 degrees to about 100 degrees, between about 40 degrees to about 120 degrees, between about 40 degrees to about 140 degrees, between about 40 degrees to about 160 degrees, between about 40 degrees to about 175 degrees, between about 60 degrees to about 80 degrees, between about 60 degrees to about 100 degrees, between about 60 degrees to about 120 degrees, between about 60 degrees to about 140 degrees, between about 60 degrees to about 160 degrees, between about 60 degrees to about 175 degrees, between about 80 degrees to about 100 degrees, between about 80 degrees to about 120 degrees, between about 80 degrees to about 140 degrees, between about 80 degrees to about 160 degrees, between about 80 degrees to about 175 degrees, between about 100 degrees to about 120 degrees, between about 100 degrees to about 140 degrees, between about 100 degrees to about 160 degrees, between about 100 degrees to about 175 degrees, between about 120 degrees to about 140 degrees, between about 120 degrees to about 160 degrees, between about 120 degrees to about 175 degrees, between about 140 degrees to about 160 degrees, between about 140 degrees to about 175 degrees, or between about 160 degrees to about 175 degrees. In some embodiments, two or more of the at least three tapered interior surfaces form an aperture angle of about 5 degrees, about 10 degrees, about 20 degrees, about 40 degrees, about 60 degrees, about 80 degrees, about 100 degrees, about 120 degrees, about 140 degrees, about 160 degrees, or about 175 degrees, including increments therein. 
     In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of at least about 10{circumflex over ( )}−9 meters. In some embodiments, the cavity has a wall with a wall thickness of at most about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−6 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−9 meters to about 1.0 meter, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−5 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−6 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−6 meters to about 1.0 meter, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−4 meters, between about 10{circumflex over ( )}−5 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−5 meters to about 1.0 meter, between about 10{circumflex over ( )}−4 meters to about 10{circumflex over ( )}−3 meters, between about 10{circumflex over ( )}−4 meters to about 1.0 meter, or between about 10{circumflex over ( )}−3 meters to about 1.0 meter. In some embodiments, the cavity has a wall with a wall thickness of about 10{circumflex over ( )}−9 meters, about 10{circumflex over ( )}−6 meters, about 10{circumflex over ( )}−5 meters, about 10{circumflex over ( )}−4 meters, about 10{circumflex over ( )}−3 meters, or about 1.0 meter, including increments therein. 
     In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity comprises 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 sides. In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity is substantially equilateral. In some embodiments, one or both the base interior surface and the truncated interior surface of the cavity is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or more of the at least three tapered interior surfaces and the truncated interior surface, which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various novel features of the disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments and the accompanying drawings. 
         FIG. 1  is an exemplary schematic diagram of a non-limiting electromagnetic energy momentum thruster. 
         FIG. 2  is an exemplary perspective view of a non-limiting conical cavity resonator. 
         FIG. 3  is an exemplary perspective cross section view of a non-limiting conical cavity resonator. 
         FIG. 4  is an exemplary perspective view of a non-limiting truncated conical cavity resonator. 
         FIG. 5  is an exemplary perspective cross section view of a non-limiting truncated conical cavity resonator. 
         FIG. 6  is an exemplary perspective view of a non-limiting pyramidal cavity resonator. 
         FIG. 7  is an exemplary perspective cross section view of a non-limiting pyramidal cavity resonator. 
         FIG. 8  is an exemplary perspective view of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 9  is an exemplary perspective cross section view of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 10  is an exemplary cross section view of a non-limiting tapered cavity resonator. 
         FIG. 11  is an exemplary cross section view of a non-limiting tapered cavity resonator comprising a substantially flat base interior surface. 
         FIG. 12  is an exemplary cross section view of a non-limiting tapered cavity resonator comprising a base radiation source. 
         FIG. 13  is an exemplary cross section view of a non-limiting tapered cavity resonator comprising a substantially flat base interior surface and a base radiation source. 
         FIG. 14  is an exemplary cross section view of a non-limiting tapered cavity resonator comprising a side radiation source. 
         FIG. 15  is an exemplary cross section view of a non-limiting tapered cavity comprising a substantially flat base interior surface and a side radiation source. 
         FIG. 16  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator. 
         FIG. 17  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 18  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator comprising a base radiation source. 
         FIG. 19  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator comprising a substantially flat base and truncated interior surfaces, and a base radiation source. 
         FIG. 20  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator comprising a side radiation source. 
         FIG. 21  is an exemplary cross section view of a non-limiting truncated tapered cavity resonator comprising a substantially flat base and truncated interior surfaces, and a side radiation source. 
         FIG. 22  is a non-limiting exemplary plot of a first azimuthal eigenfunction of a conical cavity resonator. 
         FIG. 23  is a non-limiting exemplary plot of a second azimuthal eigenfunction of a conical cavity resonator. 
         FIG. 24  is a non-limiting exemplary plot of a first transverse magnetic polar eigenfunction of a conical cavity resonator. 
         FIG. 25  is a non-limiting exemplary plot of a second transverse magnetic polar eigenfunction of a conical cavity resonator. 
         FIG. 26  is a non-limiting exemplary plot of a first transverse magnetic radial eigenfunction of a conical cavity resonator. 
         FIG. 27  is a non-limiting exemplary plot of a second transverse magnetic radial eigenfunction of a conical cavity resonator. 
         FIG. 28  is a non-limiting exemplary plot of a first transverse magnetic evanescent radial eigenfunction of a conical cavity resonator. 
         FIG. 29  is a non-limiting exemplary plot of a second transverse magnetic evanescent radial eigenfunction of a conical cavity resonator. 
         FIG. 30  is a non-limiting exemplary plot of a first transverse electric polar eigenfunction of a conical cavity resonator. 
         FIG. 31  is a non-limiting exemplary plot of a second transverse electric polar eigenfunction of a conical cavity resonator. 
         FIG. 32  is a non-limiting exemplary plot of a first transverse electric radial eigenfunction of a conical cavity resonator. 
         FIG. 33  is a non-limiting exemplary plot of a second transverse electric radial eigenfunction of a conical cavity resonator. 
         FIG. 34  is a non-limiting exemplary plot of a first transverse electric evanescent radial eigenfunction of a conical cavity resonator. 
         FIG. 35  is a non-limiting exemplary plot of a second transverse electric evanescent radial eigenfunction of a conical cavity resonator. 
         FIG. 36  is a non-limiting exemplary plot of a first azimuthal eigenfunction of a pyramidal cavity resonator. 
         FIG. 37  is a non-limiting exemplary plot of a second azimuthal eigenfunction of a pyramidal cavity resonator. 
         FIG. 38  is a non-limiting exemplary plot of a first transverse magnetic polar eigenfunction of a pyramidal cavity resonator. 
         FIG. 39  is a non-limiting exemplary plot of a second transverse magnetic polar eigenfunction of a pyramidal cavity resonator. 
         FIG. 40  is a non-limiting exemplary plot of a first transverse magnetic radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 41  is a non-limiting exemplary plot of a second transverse magnetic radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 42  is a non-limiting exemplary plot of a first transverse magnetic evanescent radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 43  is a non-limiting exemplary plot of a second transverse magnetic evanescent radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 44  is a non-limiting exemplary plot of a first transverse electric polar eigenfunction of a pyramidal cavity resonator. 
         FIG. 45  is a non-limiting exemplary plot of a second transverse electric polar eigenfunction of a pyramidal cavity resonator. 
         FIG. 46  is a non-limiting exemplary plot of a first transverse electric radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 47  is a non-limiting exemplary plot of a second transverse electric radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 48  is a non-limiting exemplary plot of a first transverse electric evanescent radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 49  is a non-limiting exemplary plot of a second transverse electric evanescent radial eigenfunction of a pyramidal cavity resonator. 
         FIG. 50  is an exemplary perspective view of a first three-dimensional electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 51  is an exemplary perspective view of a first three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 52  is an exemplary axial cross section view of a first electric field density plot of a non-limiting conical cavity resonator. 
         FIG. 53  is an exemplary axial cross section view of a first magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 54  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 55  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 56  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting conical cavity resonator. 
         FIG. 57  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 58  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting truncated conical cavity resonator. 
         FIG. 59  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 60  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting truncated conical cavity resonator. 
         FIG. 61  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 62  is an exemplary perspective view of a second three-dimensional electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 63  is an exemplary perspective view of a second three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 64  is an exemplary axial cross section view of a second electric field density plot of a non-limiting conical cavity resonator. 
         FIG. 65  is an exemplary axial cross section view of a second magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 66  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 67  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 68  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting conical cavity resonator. 
         FIG. 69  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 70  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting truncated conical cavity resonator. 
         FIG. 71  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 72  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting truncated conical cavity resonator. 
         FIG. 73  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 74  is an exemplary perspective view of a third three-dimensional electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 75  is an exemplary perspective view of a third three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 76  is an exemplary axial cross section view of a third electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 77  is an exemplary axial cross section view of a third magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 78  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting conical cavity resonator. 
         FIG. 79  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 80  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting conical cavity resonator. 
         FIG. 81  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
         FIG. 82  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting truncated conical cavity resonator. 
         FIG. 83  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 84  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting truncated conical cavity resonator. 
         FIG. 85  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 86  is an exemplary perspective view of a first three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 87  is an exemplary perspective view of a first three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 88  is an exemplary axial cross section view of a first electric field density plot of a non-limiting pyramidal cavity resonator. 
         FIG. 89  is an exemplary axial cross section view of a first magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 90  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 91  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 92  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting pyramidal cavity resonator. 
         FIG. 93  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 94  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 95  is an exemplary radial cross section view of a first electric field vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 96  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 97  is an exemplary radial cross section view of a first magnetic field density plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 98  is an exemplary perspective view of a second three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 99  is an exemplary perspective view of a second three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 100  is an exemplary axial cross section view of a second electric field density plot of a non-limiting pyramidal cavity resonator. 
         FIG. 101  is an exemplary axial cross section view of a second magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 102  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 103  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 104  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting pyramidal cavity resonator. 
         FIG. 105  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 106  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 107  is an exemplary radial cross section view of a second electric field vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 108  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 109  is an exemplary radial cross section view of a second magnetic field density plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 110  is an exemplary perspective view of a third three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 111  is an exemplary perspective view of a third three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 112  is an exemplary axial cross section view of a third electric field density plot of a non-limiting pyramidal cavity resonator. 
         FIG. 113  is an exemplary axial cross section view of a third magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 114  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 115  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 116  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
         FIG. 117  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
         FIG. 118  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 119  is an exemplary radial cross section view of a third electric field vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 120  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting truncated pyramidal cavity resonator. 
         FIG. 121  is an exemplary radial cross section view of a third magnetic field vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
         FIG. 122  is an exemplary perspective view of a non-limiting environmental control apparatus. 
         FIG. 123  is an exemplary cross-section view of a non-limiting environmental control apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE FIGURES 
     Disclosed herein, per  FIG. 1 , is an electromagnetic energy momentum thruster comprising a tapered cavity resonator  10  and an electromagnetic radiation source  20  in communication with the cavity resonator  10 . In some embodiments, the electromagnetic radiation source  20  is configured to emit an electromagnetic wave into the cavity resonator  10 . In some embodiments, the electromagnetic radiation source  20  is configured to emit an electromagnetic wave into the cavity resonator  10  via a transmission line  30 . In some embodiments, the electromagnetic wave has a frequency between about 1.0 MHz to about 1000 THz. In some embodiments, the cavity resonator  10  is confined within an environmental control apparatus  40 . 
     Conical Cavity Resonator Thruster 
     Provided herein per  FIGS. 2, 3, and 10-15  is an electromagnetic energy momentum thruster comprising a conical cavity resonator  100  and a base electromagnetic radiation source  600   a  or a side electromagnetic radiation source  600   b . In some embodiments, the cavity resonator  100  forms a cavity  180  having a base interior surface  110  and a tapered interior surface  120 , wherein the tapered interior surface converges to an apex point  130 . 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to emit an electromagnetic wave into the cavity  180  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the side electromagnetic radiation source  600   b  is configured to emit an electromagnetic wave into the cavity  180  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to produce the frequency of the electromagnetic wave in evanescence, so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, the base interior surface  110 , and the asymptotic field amplitude is at, or adjacent to, one or both the tapered interior surface  120  and the apex point  130 . In some embodiments, the side electromagnetic radiation source  600   b  is configured to produce the frequency of the electromagnetic wave in evanescence, so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, one or both the tapered interior surface  120  and the apex point  130 , and the asymptotic field amplitude is at, or adjacent to, the base interior surface  110 . 
     In some embodiments, the cavity  180  includes an overall interior surface comprising the base interior surface  110  and the tapered interior surface  120 . In some embodiments, substantially the entire overall interior surface of the cavity  180  is electrically conductive. In some embodiments, substantially the entire overall interior surface of the cavity  180  is superconductive. In some embodiments, substantially the entire overall interior surface of the cavity  180  is electrically conductive, and has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, substantially the entire overall interior surface of the cavity  180  is superconductive, and has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. 
     In some embodiments, substantially the entire overall interior surface of the cavity  180  comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. In some embodiments, substantially the entire overall interior surface of the cavity  180  comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity  180  is empty. In some embodiments, the cavity  180  comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity  180  comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr. 
     In some embodiments, the cavity  180  comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity  180  comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic radiation source is located inside the cavity  180  at, or adjacent to, a maximum field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity  180  has at least one of a width  140  and a height  150  between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the width  140  is measured as a maximum diameter of the base interior surface  110 . In some embodiments, the height  150  is measured as a distance from the base interior surface  110  to the apex point  130 . In some embodiments, the tapered interior surface  120  forms an aperture angle  160  between about 5 degrees to about 175 degrees. In some embodiments, the aperture angle  160  is measured as the interior angle of the tapered interior surface  120  at the apex point  130 . In some embodiments, the cavity  180  has a wall with a wall thickness  170  between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the wall thickness  170  is measured as a normal distance between the overall interior surface of the cavity  180  and an exterior of the cavity resonator  100 . In some embodiments, the base interior surface  110  has a different wall thickness  170  than the tapered interior surface  120 . In some embodiments, the base interior surface  110  has about the same wall thickness  170  as the tapered interior surface  120 . 
     In some embodiments, the base interior surface  110  is substantially elliptical. In some embodiments, the base interior surface  110  is substantially circular. In some embodiments, the base interior surface  110  is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface  110 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or both the tapered interior surface  120  and the apex point  130 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Truncated Conical Cavity Resonator Thruster 
     Provided herein per  FIGS. 4, 5, and 16-21  is an electromagnetic energy momentum thruster comprising a truncated conical cavity resonator  200  and a base electromagnetic radiation source  600   a  or a side electromagnetic radiation source  600   b . In some embodiments, the cavity resonator  200  forms a cavity  280  having a base interior surface  210 , a tapered interior surface  220 , and a truncated interior surface  230  opposing the base interior surface  210 , the tapered interior surface  220  being between the base interior surface  210  and the truncated interior surface  230 . 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to emit an electromagnetic wave into the cavity  280  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the side electromagnetic radiation source  600   b  is configured to emit an electromagnetic wave into the cavity  280  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to produce the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, the base interior surface  210 , and the asymptotic field amplitude is at, or adjacent to, one or both the tapered interior surface  220  and the truncated interior surface  230 . In some embodiments, the side electromagnetic radiation source  600   b  is configured to produce the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, one or both the tapered interior surface  220  and the truncated interior surface  230 , and the asymptotic field amplitude is at, or adjacent to, the base interior surface  210 . 
     In some embodiments, the cavity  280  includes an overall interior surface comprising the base interior surface  210 , the tapered interior surface  220 , and the truncated interior surface  230 . In some embodiments, substantially the entire overall interior surface of the cavity  280  is electrically conductive. In some embodiments, substantially the entire overall interior surface of the cavity  280  is superconductive. In some embodiments, substantially the entire overall interior surface of the cavity  280  is electrically conductive, and has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, substantially the entire overall interior surface of the cavity  280  is superconductive, and has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. 
     In some embodiments, substantially the entire overall interior surface of the cavity  280  comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. In some embodiments, substantially the entire overall interior surface of the cavity  280  comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 Ba 5 Cu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity  280  is empty. In some embodiments, the cavity  280  comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity  280  comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr. 
     In some embodiments, the cavity  280  comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity  280  comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic radiation source is located inside the cavity  280  at, or adjacent to, a maximum field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity  280  has at least one of a width  240  and a height  250  between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the width  240  is measured as a maximum diameter of the base interior surface  210 . In some embodiments, the height  250  is measured as a normal distance from the base interior surface  210  to the truncated interior surface  230 . In some embodiments, the tapered interior surface  220  forms an aperture angle  260  between about 5 degrees to about 175 degrees. In some embodiments, the aperture angle  260  is measured as the interior angle of the tapered interior surface  220 . In some embodiments, the cavity  280  has a wall with a wall thickness  270  between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the wall thickness  270  is measured as a normal distance between the overall interior surface of the cavity  280  and an exterior of the cavity resonator  200 . In some embodiments, the base interior surface  210  has a different wall thickness  270  than the tapered interior surface  220 . In some embodiments, the base interior surface  210  has about the same wall thickness  270  as the tapered interior surface  220 . In some embodiments, the truncated interior surface  230  has a different wall thickness  270  than the tapered interior surface  220 . In some embodiments, the truncated interior surface  230  has about the same wall thickness  270  the tapered interior surface  220 . In some embodiments, the base interior surface  210  has a different wall thickness  270  than the truncated interior surface  230 . In some embodiments, the base interior surface  210  has about the same wall thickness  270  as the truncated interior surface  230 . 
     In some embodiments, one or both the base interior surface  210  and the truncated interior surface  230  is substantially elliptical. In some embodiments, one or both the base interior surface  210  and the truncated interior surface  230  is substantially circular. In some embodiments, one or both the base interior surface  210  and the truncated interior surface  230  is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface  210 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or both the tapered interior surface  220  and the truncated interior surface  230 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Pyramidal Cavity Resonator Thruster 
     Provided herein per  FIGS. 6, 7, and 10-15  is an electromagnetic energy momentum thruster comprising a pyramidal cavity resonator  300  and a base electromagnetic radiation source  600   a  or a side electromagnetic radiation source  600   b . In some embodiments, the cavity resonator  300  forms a cavity  380  having a base interior surface  310  and at least three tapered interior surfaces  320 , the tapered interior surfaces  320  converging to an apex point  330 . 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to emit an electromagnetic wave into the cavity  380  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the side electromagnetic radiation source  600   b  is configured to emit an electromagnetic wave into the cavity  380  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, the base interior surface  310 , and the asymptotic field amplitude is at, or adjacent to, one or more of the at least three tapered interior surfaces  320  and the apex point  330 . In some embodiments, the side electromagnetic radiation source  600   b  is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, one or more of the at least three tapered interior surfaces  320  and the apex point  330 , and the asymptotic field amplitude is at, or adjacent to, the base interior surface  310 . 
     In some embodiments, the cavity  380  includes an overall interior surface comprising the base interior surface  310  and the at least three tapered interior surfaces  320 . In some embodiments, substantially the entire overall interior surface of the cavity  380  is electrically conductive. In some embodiments, substantially the entire overall interior surface of the cavity  380  is superconductive. In some embodiments, substantially the entire overall interior surface of the cavity  380  is electrically conductive, and has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, substantially the entire overall interior surface of the cavity  380  is superconductive, and has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. 
     In some embodiments, substantially the entire overall interior surface of the cavity  380  comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. In some embodiments, substantially the entire overall interior surface of the cavity  380  comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 BasCu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity  380  is empty. In some embodiments, the cavity  380  comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity  380  comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr. 
     In some embodiments, the cavity  380  comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity  380  comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic radiation source is located inside the cavity  380  at, or adjacent to, a maximum field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity  380  has at least one of a width  340  and a height  350  between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the width  340  is measured as a maximum diameter of the base interior surface  310 . In some embodiments, the height  350  is measured as a distance from the base interior surface  310  to the apex point  330 . In some embodiments, two or more of the at least three tapered interior surfaces  320  form an aperture angle  360  between about 5 degrees to about 175 degrees. In some embodiments, the aperture angle  360  is measured as an internal angle between two or more of the at least three tapered interior surfaces  320  at the apex point  330 . In some embodiments, the cavity has a wall with a wall thickness  370  between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the wall thickness  370  is measured as a normal distance between the overall interior surface of the cavity  380  and an exterior of the cavity resonator  300 . In some embodiments, the base interior surface  310  has a different wall thickness  370  than as at least one of the at least three the tapered interior surfaces  320 . In some embodiments, the base interior surface  310  has about the same wall thickness  370  as at least one of the at least three the tapered interior surfaces  320 . 
     In some embodiments, the base interior surface  310  comprises 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or more sides. In some embodiments the base interior surface  310  is substantially equilateral. In some embodiments, the base interior surface  310  is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface  310 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or more of the at least three tapered interior surfaces  320  and the apex point  330 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Truncated Pyramidal Cavity Resonator Thruster 
     Provided herein per  FIGS. 8, 9, and 16-21  is an electromagnetic energy momentum thruster comprising a truncated pyramidal cavity resonator  400  and a base electromagnetic radiation source  600   a  or a side electromagnetic radiation source  600   b . In some embodiments, the cavity resonator  400  forms a cavity  480  having a base interior surface  410 , at least three tapered interior surfaces  420 , and a truncated interior surface  430  opposing the base interior surface  410 , the at least three tapered interior surfaces  420  being between the base interior surface  410  and truncated interior surfaces  430 . 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to emit an electromagnetic wave into the cavity  480  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the side electromagnetic radiation source  600   b  is configured to emit an electromagnetic wave into the cavity  480  having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, the base interior surface  410 , and the asymptotic field amplitude is at, or adjacent to, one or more of the at least three tapered interior surfaces  420  and the truncated interior surface  430 . In some embodiments, the side electromagnetic radiation source  600   b  is configured to produce the frequency of the electromagnetic wave in evanescence so that the electromagnetic wave has a maximum field amplitude and an asymptotic field amplitude. In some embodiments, the maximum field amplitude is at, or adjacent to, one or more of the at least three tapered interior surfaces  420  and the truncated interior surface  430 , and the asymptotic field amplitude is at, or adjacent to, the base interior surface  410 . 
     In some embodiments, the cavity  480  includes an overall interior surface comprising the base interior surface  410 , the at least three tapered interior surfaces  420 , and the truncated interior surface  430 . In some embodiments, substantially the entire overall interior surface of the cavity  480  is electrically conductive. In some embodiments, substantially the entire overall interior surface of the cavity  480  is superconductive. In some embodiments, substantially the entire overall interior surface of the cavity  480  is electrically conductive, and has a quality factor between about 10{circumflex over ( )}3 to about 10{circumflex over ( )}9. In some embodiments, the entire overall interior surface of the cavity  480  is superconductive, and has a quality factor between about 10{circumflex over ( )}6 to about 10{circumflex over ( )}15. 
     In some embodiments, substantially the entire overall interior surface of the cavity  480  comprises aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, carbon, chromium, cobalt, copper, gallium, gold, hydrogen, indium, iron, lanthanum, lead, lithium, magnesium, manganese, mercury, molybdenum, nickel, niobium, nitrogen, oxygen, palladium, phosphorus, platinum, scandium, silicon, silver, strontium, sulfur, tantalum, technetium, tin, titanium, tungsten, vanadium, yttrium, zinc, zirconium, or any combination thereof. In some embodiments, substantially the entire overall interior surface of the cavity  480  comprises aluminum, barium, beryllium, bismuth, cadmium, calcium, copper, gallium, gadolinium, germanium, lanthanum, lead, lithium, indium, mercury, molybdenum, niobium, nitrogen, osmium, oxygen, protactinium, rhenium, ruthenium, silicon, strontium, sulfur, tantalum, technetium, thallium, thorium, titanium, tin, vanadium, yttrium, zinc, zirconium, NbTi, PbMoS, V 3 Ga, NbN, V 3 Si, Nb 3 Sn, Nb 3 Al, Nb 3 (AlGe), Nb 3 Ge, Bi 2 Sr 2 CuO 6 , Bi 2 Sr 2 CaCu 2 O 8 , Bi 2 Sr 2 Ca 2 Cu 3 O 10 , YBa 2 Cu 3 O 7 , YBa 2 Cu 4 O 8 , Y 2 Ba 4 Cu 7 O 15 , Y 3 Ba 5 Cu 8 O 18 , Tl 2 Ba 2 CuO 6 , Tl 2 Ba 2 CaCu 2 O 8 , Tl 2 Ba 2 Ca 2 Cu 3 O 10 , TlBa 2 Ca 3 Cu 4 O 11 , HgBa 2 CuO 4 , HgBa 2 CaCu 2 O 6 , HgBa 2 Ca 2 Cu 3 O 8 , or any combination thereof. 
     In some embodiments, the cavity  480  is empty. In some embodiments, the cavity  480  comprises a vacuum with a pressure between about 10{circumflex over ( )}−24 Torr to about 10{circumflex over ( )}3 Torr. In some embodiments, the cavity  480  comprises a vacuum with a pressure of about 10{circumflex over ( )}−24 Torr, about 10{circumflex over ( )}−21 Torr, about 10{circumflex over ( )}−18 Torr, about 10{circumflex over ( )}−15 Torr, about 10{circumflex over ( )}−12 Torr, about 10{circumflex over ( )}−9 Torr, about 10{circumflex over ( )}−6 Torr, about 10{circumflex over ( )}−3 Torr, about 1.0 Torr, or about 10{circumflex over ( )}3 Torr. 
     In some embodiments, the cavity  480  comprises a thermal reservoir with a temperature between about 10{circumflex over ( )}−3 Kelvin to about 10{circumflex over ( )}3 Kelvin. In some embodiments, the cavity  480  comprises a thermal reservoir with a temperature of about 10{circumflex over ( )}−3 Kelvin, about 1 Kelvin, about 5 Kelvin, about 10 Kelvin, about 25 Kelvin, about 50 Kelvin, about 75 Kelvin, about 100 Kelvin, about 150 Kelvin, about 200 Kelvin, about 300 Kelvin, or about 10{circumflex over ( )}3 Kelvin. 
     In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse magnetic wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N1 and an azimuthal mode number of N2, where N1 and N2 are an integers from 0 to 1000, and N1 is greater than or equal to N2. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of 0, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic wave comprises a transverse electric wave with a polar mode number of N and an azimuthal mode number of N, where N is an integer from 0 to 1000. In some embodiments, the electromagnetic radiation source is located inside the cavity  480  at, or adjacent to, a maximum field amplitude of the electromagnetic wave. 
     In some embodiments, the cavity  480  has at least one of a width  440  and a height  450  between about 10{circumflex over ( )}−9 meters to about 10{circumflex over ( )}3 meters. In some embodiments, the width  440  is measured as a normal width of the base interior surface  410 . In some embodiments, the height  450  is measured as a normal distance from the base interior surface  410  to the truncated interior surface  430 . In some embodiments, two or more of the at least three tapered interior surfaces  420  form an aperture angle  460  between about 5 degrees to about 175 degrees. In some embodiments, the aperture angle  460  is measured as an internal angle between two or more of the at least three tapered interior surfaces  420 . In some embodiments, the cavity  480  has a wall with a wall thickness  470  between about 10{circumflex over ( )}−9 meters to about 1.0 meter. In some embodiments, the wall thickness  470  is measured as a normal distance between the overall interior surface of the cavity  480  and an exterior of the cavity resonator  400 . In some embodiments, the base interior surface  410  has a different wall thickness  470  than at least one of the three or more tapered interior surfaces  420 . In some embodiments, the base interior surface  410  has about the same wall thickness  470  as at least one of the three or more tapered interior surfaces  420 . In some embodiments, the truncated interior surface  430  has a different wall thickness  470  than at least one of the three or more tapered interior surfaces  420 . In some embodiments, the truncated interior surface  430  has about the same wall thickness  470  as at least one of the three or more tapered interior surfaces  420 . In some embodiments, the base interior surface  410  has a different wall thickness  470  than the truncated interior surface  430 . In some embodiments, the base interior surface  410  has about the same wall thickness  470  as the truncated interior surface  430 . 
     In some embodiments, one or both the base interior surface  410  and the truncated interior surface  430  comprises 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or more sides. In some embodiments, one or both the base interior surface  410  and the truncated interior surface  430  is substantially equilateral. In some embodiments, one or both the base interior surface  410  and the truncated interior surface  430  is substantially flat. 
     In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, the base interior surface  410 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. In some embodiments, the electromagnetic wave forms an electromagnetic energy momentum tensor with an amplitude maximum at, or adjacent to, one or more of the at least three tapered interior surfaces  420  and the truncated interior surface  430 , which results in one or more of a metric tensor curvature, a thrust, and an acceleration of the thruster. 
     Electromagnetic Radiation Source 
     Provided herein is an electromagnetic energy momentum thruster comprising a cavity resonator forming a cavity, and an electromagnetic radiation source. 
     In some embodiments, per  FIGS. 12 and 13 , the electromagnetic energy momentum thruster comprises a tapered cavity resonator  500  and a base electromagnetic radiation source  600   a . In some embodiments, per  FIGS. 14 and 15 , the electromagnetic energy momentum thruster comprises a tapered cavity resonator  500  and a side electromagnetic radiation source  600   b.    
     In some embodiments, per  FIGS. 18 and 19 , the electromagnetic energy momentum thruster comprises a truncated tapered cavity resonator  550  and a base electromagnetic radiation source  600   a . In some embodiments, per  FIGS. 20 and 21 , the electromagnetic energy momentum thruster comprises a truncated tapered cavity resonator  550  and a side electromagnetic radiation source  600   b.    
     In some embodiments, the tapered cavity resonator  500  comprises a pyramidal or a conical cavity resonator. In some embodiments, the truncated tapered cavity resonator  550  comprises a truncated pyramidal or a truncated conical cavity resonator. 
     In some embodiments, the base radiation source  600   a  emits the electromagnetic wave from the base interior surface of the tapered cavity resonator  500  or the truncated tapered cavity resonator  550 . In some embodiments, the base radiation source  600   a  is affixed to the base interior surface of the tapered cavity resonator  500  or the truncated tapered cavity resonator  550 . In some embodiments, the side radiation source  600   b  emits the electromagnetic wave from the tapered interior surface of the tapered cavity resonator  500  or the truncated tapered cavity resonator  550 . In some embodiments, the side radiation source  600   b  is affixed to the tapered interior surface of the tapered cavity resonator  500  or the truncated tapered cavity resonator  550 . 
     In some embodiments, the base electromagnetic radiation source  600   a  is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}0 MHz to about 10{circumflex over ( )}9 MHz. In some embodiments, the side electromagnetic radiation source  600   b  is configured to emit an electromagnetic wave into the cavity resonator having a frequency between about 10{circumflex over ( )}1 MHz to about 10{circumflex over ( )}9 MHz. 
     Environmental Control Apparatus 
     Provided herein, per  FIGS. 122 and 123 , is an exemplary environmental control apparatus  1000 . In some embodiments, the environmental control apparatus  1000  comprises a transmission line  1001 , an instrumentation channel  1002 , a coolant input  1003 , and a coolant output  1004 . In some embodiments, the coolant comprises a gaseous coolant, a liquid coolant, a cryogen coolant, or any combination thereof. 
     In some embodiments, the exemplary environmental control apparatus  1000  comprises at least one of a clamp, a clasp, a cam, a handle, a gasket, an insulator, and a probe. 
     EXAMPLES 
     The following illustrative examples are representative of embodiments of the hardware applications, systems, and methods described herein and are not meant to be limiting in any way. Exemplary plots of the transverse magnetic waves and the transverse electric waves of a non-limiting conical cavity resonator, a non-limiting truncated conical cavity resonator, a non-limiting pyramidal cavity resonator, and a non-limiting truncated pyramidal cavity resonator are shown in  FIGS. 22-121 . 
     Example 1—Transverse Electric Wave Frequency of a Conical Cavity Resonator 
     In some embodiments, a frequency of a hollow conical cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) of the resonator: 
         m=n  where  n= 0,1,2, . . . . 
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), and a polar wave equation (P l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       θ 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           θ 
                         
                         ) 
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
       [( kr ) j   l ( kr )] r=0 =0 and [( kr ) j   l ( kr )] r=r     l   =0 
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           j 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 0 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     or 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               j 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 22 and 23  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a conical cavity resonator, respectively.  FIGS. 30 and 31  are non-limiting exemplary plots of a first and a second transverse electric polar eigenfunction of a conical cavity resonator, respectively.  FIGS. 32 and 33  are non-limiting exemplary plots of a first and a second transverse electric radial eigenfunction of a conical cavity resonator, respectively.  FIGS. 34 and 35  are non-limiting exemplary plots of a first and a second transverse electric evanescent radial eigenfunction of a conical cavity resonator, respectively. 
       FIG. 74  is an exemplary perspective view of a first transverse electric three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 75  is an exemplary perspective view of a first transverse electric three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 76  is an exemplary axial cross section view of a first electric field transverse electric vector plot of a non-limiting conical cavity resonator.  FIG. 77  is an exemplary axial cross section view of a first magnetic field transverse electric vector plot of a non-limiting conical cavity resonator. 
       FIG. 78  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting conical cavity resonator.  FIG. 79  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
       FIG. 80  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting conical cavity resonator.  FIG. 81  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting conical cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from the base interior surface. 
     Example 2—Transverse Magnetic Wave Frequency of a Conical Cavity Resonator 
     In some embodiments, a frequency of a hollow conical cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) of the resonator: 
         m=n  where  n= 0,1,2, . . . . 
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), and a polar wave equation (P l   m (cos θ)) of the resonator: 
       [( P   l   m (cos θ)] θ=θ     0   =0
 
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           j 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 0 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     and 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               j 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
       [( kr ) j   l ( kr )] r=0 =0 or [( kr ) j   l ( kr )] r=r     1   =0 
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 22 and 23  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a conical cavity resonator, respectively.  FIGS. 24 and 25  are non-limiting exemplary plots of a first and a second transverse magnetic polar eigenfunction of a conical cavity resonator, respectively.  FIGS. 26 and 27  are non-limiting exemplary plots of a first and a second transverse magnetic radial eigenfunction of a conical cavity resonator, respectively.  FIGS. 28 and 29  are non-limiting exemplary plots of a first and a second transverse magnetic evanescent radial eigenfunction of a conical cavity resonator, respectively. 
       FIG. 50  is an exemplary perspective view of a first transverse magnetic three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 51  is an exemplary perspective view of a first transverse magnetic three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 52  is an exemplary axial cross section view of a first electric field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 53  is an exemplary axial cross section view of a first magnetic field transverse magnetic vector plot of a non-limiting conical cavity resonator. 
       FIG. 54  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting conical cavity resonator.  FIG. 55  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
       FIG. 56  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 57  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
       FIG. 62  is an exemplary perspective view of a second transverse magnetic three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 63  is an exemplary perspective view of a second transverse magnetic three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 64  is an exemplary axial cross section view of a second electric field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 65  is an exemplary axial cross section view of a second magnetic field transverse magnetic vector plot of a non-limiting conical cavity resonator. 
       FIG. 66  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting conical cavity resonator.  FIG. 67  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
       FIG. 68  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 69  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting conical cavity resonator comprising a substantially flat base interior surface. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting conical cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from the tapered interior surface. 
     Example 3—Transverse Electric Wave Frequency of a Truncated Conical Cavity Resonator 
     In some embodiments, a frequency of a hollow conical cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) of the resonator: 
         m=n  where  n= 0,1,2, . . . . 
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), and a polar wave equation (P l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       θ 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           θ 
                         
                         ) 
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
       [( kr ) h   l ( kr )] r=0 =0 and [( kr ) h   l ( kr )] r=r     1   =0 
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), a truncated radial length (r 0 ), and a radial wave equation (h l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           h 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 
                   r 
                   0 
                 
               
             
             = 
             
               0 
               ⁢ 
               
                   
               
               ⁢ 
               
                 
                   or 
                   ⁢ 
                   
                       
                   
                   [ 
                   
                     
                       d 
                       
                         d 
                         ⁢ 
                         r 
                       
                     
                     ⁡ 
                     
                       [ 
                       
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                         ⁢ 
                         
                           
                             h 
                             l 
                           
                           ⁡ 
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                         
                       
                       ] 
                     
                   
                   ] 
                 
                 
                   r 
                   = 
                   
                     r 
                     1 
                   
                 
               
             
           
         
       
     
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 22 and 23  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a conical cavity resonator, respectively.  FIGS. 30 and 31  are non-limiting exemplary plots of a first and a second transverse electric polar eigenfunction of a conical cavity resonator, respectively.  FIGS. 32 and 33  are non-limiting exemplary plots of a first and a second transverse electric radial eigenfunction of a conical cavity resonator, respectively.  FIGS. 34 and 35  are non-limiting exemplary plots of a first and a second transverse electric evanescent radial eigenfunction of a conical cavity resonator, respectively. 
       FIG. 74  is an exemplary perspective view of a first transverse electric three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 75  is an exemplary perspective view of a first transverse electric three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 76  is an exemplary axial cross section view of a first electric field transverse electric vector plot of a non-limiting conical cavity resonator.  FIG. 77  is an exemplary axial cross section view of a first magnetic field transverse electric vector plot of a non-limiting conical cavity resonator. 
       FIG. 82  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting truncated conical cavity resonator.  FIG. 83  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 84  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting truncated conical cavity resonator.  FIG. 85  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting conical cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from the base interior surface. 
     Example 4—Transverse Magnetic Wave Frequency of a Truncated Conical Cavity Resonator 
     In some embodiments, a frequency of a hollow conical cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) of the resonator: 
         m=n  where  n= 0,1,2, . . . . 
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), and a polar wave equation (P l   m (cos θ)) of the resonator: 
       [( P   l   m (cos θ)] θ=θ     0   =0
 
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           h 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 
                   r 
                   0 
                 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     and 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               h 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
       [( kr ) h   l ( kr )] r=r     0   =0 or [( kr ) h   l ( kr )] r=r     1   =0 
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 22 and 23  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a conical cavity resonator, respectively.  FIGS. 24 and 25  are non-limiting exemplary plots of a first and a second transverse magnetic polar eigenfunction of a conical cavity resonator, respectively.  FIGS. 26 and 27  are non-limiting exemplary plots of a first and a second transverse magnetic radial eigenfunction of a conical cavity resonator, respectively.  FIGS. 28 and 29  are non-limiting exemplary plots of a first and a second transverse magnetic evanescent radial eigenfunction of a conical cavity resonator, respectively. 
       FIG. 50  is an exemplary perspective view of a first transverse magnetic three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 51  is an exemplary perspective view of a first transverse magnetic three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 52  is an exemplary axial cross section view of a first electric field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 53  is an exemplary axial cross section view of a first magnetic field transverse magnetic vector plot of a non-limiting conical cavity resonator. 
       FIG. 58  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting truncated conical cavity resonator.  FIG. 59  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 60  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting truncated conical cavity resonator.  FIG. 61  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 62  is an exemplary perspective view of a second transverse magnetic three-dimensional electric field vector plot of a non-limiting conical cavity resonator.  FIG. 63  is an exemplary perspective view of a second transverse magnetic three-dimensional magnetic field vector plot of a non-limiting conical cavity resonator. 
       FIG. 64  is an exemplary axial cross section view of a second electric field transverse magnetic density plot of a non-limiting conical cavity resonator.  FIG. 65  is an exemplary axial cross section view of a second magnetic field transverse magnetic vector plot of a non-limiting conical cavity resonator. 
       FIG. 70  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting truncated conical cavity resonator.  FIG. 71  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 72  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting truncated conical cavity resonator.  FIG. 73  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting truncated conical cavity resonator comprising a substantially flat base and truncated interior surfaces. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting conical cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from one or both the tapered interior surface and the truncated interior surface. 
     Example 5—Transverse Electric Wave Frequency of a Pyramidal Cavity Resonator 
     In some embodiments, a frequency of a hollow pyramidal cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) and a taper angle (φ 0 ) of the resonator: 
     
       
         
           
             
               m 
               = 
               
                 
                   
                     
                       n 
                       ⁢ 
                       π 
                     
                     
                       φ 
                       0 
                     
                   
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   where 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   n 
                 
                 = 
                 0 
               
             
             , 
             1 
             , 
             2 
             , 
             … 
           
         
       
     
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), a polar wave equation (P l   m (cos θ)), and a polar wave equation (Q l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       θ 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         
                           
                             P 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               cos 
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                         ⁢ 
                         
                           
                             Q 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               
                                 - 
                                 cos 
                               
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                       
                       - 
                       
                         
                           
                             P 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               
                                 - 
                                 cos 
                               
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                         ⁢ 
                         
                           
                             Q 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               cos 
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
       [( kr ) j   l ( kr )] r=0 =0 and [( kr ) j   l ( kr )] r=r     1   =0 
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           j 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 0 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     or 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               j 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 36 and 37  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 44 and 45  are non-limiting exemplary plots of a first and a second transverse electric polar eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 46 and 47  are non-limiting exemplary plots of a first and a second transverse electric radial eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 48 and 49  are non-limiting exemplary plots of a first and a second transverse electric evanescent radial eigenfunction of a pyramidal cavity resonator, respectively. 
       FIG. 110  is an exemplary perspective view of a first transverse electric three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 111  is an exemplary perspective view of a first transverse electric three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 112  is an exemplary axial cross section view of a first electric field transverse electric density plot of a non-limiting pyramidal cavity resonator.  FIG. 113  is an exemplary axial cross section view of a first magnetic field transverse electric vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 114  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting pyramidal cavity resonator.  FIG. 115  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting pyramidal resonator comprising a substantially flat base interior surface. 
       FIG. 116  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting pyramidal cavity resonator.  FIG. 117  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting pyramidal cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from the base interior surface. 
     Example 6—Transverse Magnetic Wave Frequency of a Pyramidal Cavity Resonator 
     In some embodiments, a frequency of a hollow pyramidal cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) and a taper angle (φ 0 ) of the resonator: 
     
       
         
           
             
               m 
               = 
               
                 
                   
                     
                       n 
                       ⁢ 
                       π 
                     
                     
                       φ 
                       0 
                     
                   
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   where 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   n 
                 
                 = 
                 0 
               
             
             , 
             1 
             , 
             2 
             , 
             … 
           
         
       
     
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), a polar wave equation (P l   m (cos θ)), and a polar wave equation (Q l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                     ⁢ 
                     
                       
                         Q 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           
                             - 
                             cos 
                           
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                   
                   - 
                   
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           
                             - 
                             cos 
                           
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                     ⁢ 
                     
                       
                         Q 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           j 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 0 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     and 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               j 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), and a radial wave equation (j l (kr)) of the resonator: 
       [( kr ) j   l ( kr )] r=0 =0 or [( kr ) j   l ( kr )] r=r     1   =0 
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 36 and 37  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 38 and 39  are non-limiting exemplary plots of a first and a second transverse magnetic polar eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 40 and 41  are non-limiting exemplary plots of a first and a second transverse magnetic radial eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 42 and 43  are non-limiting exemplary plots of a first and a second transverse magnetic evanescent radial eigenfunction of a pyramidal cavity resonator, respectively. 
       FIG. 86  is an exemplary perspective view of a first transverse magnetic three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 87  is an exemplary perspective view of a first transverse magnetic three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 88  is an exemplary axial cross section view of a first electric field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 89  is an exemplary axial cross section view of a first magnetic field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 90  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator.  FIG. 91  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
       FIG. 92  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 93  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
       FIG. 98  is an exemplary perspective view of a second transverse magnetic three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 99  is an exemplary perspective view of a second transverse magnetic three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 100  is an exemplary axial cross section view of a second electric field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 101  is an exemplary axial cross section view of a second magnetic field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 102  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator.  FIG. 103  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
       FIG. 104  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 105  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting pyramidal cavity resonator comprising a substantially flat base interior surface. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting pyramidal cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from one or more of the at least three tapered interior surfaces. 
     Example 7—Transverse Electric Wave Frequency of a Truncated Pyramidal Cavity Resonator 
     In some embodiments, a frequency of a hollow pyramidal cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) and a taper angle (φ 0 ) of the resonator: 
     
       
         
           
             
               m 
               = 
               
                 
                   
                     
                       n 
                       ⁢ 
                       π 
                     
                     
                       φ 
                       0 
                     
                   
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   where 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   n 
                 
                 = 
                 0 
               
             
             , 
             1 
             , 
             2 
             , 
             … 
           
         
       
     
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), a polar wave equation (P l   m (cos θ)), and a polar wave equation (Q l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       θ 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         
                           
                             P 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               cos 
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                         ⁢ 
                         
                           
                             Q 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               
                                 - 
                                 cos 
                               
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                       
                       - 
                       
                         
                           
                             P 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               
                                 - 
                                 cos 
                               
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                         ⁢ 
                         
                           
                             Q 
                             l 
                             m 
                           
                           ⁡ 
                           
                             ( 
                             
                               cos 
                               ⁢ 
                               
                                 
                                   θ 
                                   0 
                                 
                                 2 
                               
                             
                             ) 
                           
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
       [( kr ) h   l ( kr )] r=r     0   =0 and [( kr ) h   l ( kr )] r=r     1   =0 
     For a radial eigenvalue (k), a polar eigenvalue (l), a radial length (r 1 ), a truncated radial length (r 0 ), and a radial wave equation (h l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         
                           k 
                           ⁢ 
                           r 
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           h 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 0 
               
             
             = 
             
               0 
               ⁢ 
               
                   
               
               ⁢ 
               
                 
                   or 
                   ⁢ 
                   
                       
                   
                   [ 
                   
                     
                       d 
                       
                         d 
                         ⁢ 
                         r 
                       
                     
                     ⁡ 
                     
                       [ 
                       
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                         ⁢ 
                         
                           
                             h 
                             l 
                           
                           ⁡ 
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                         
                       
                       ] 
                     
                   
                   ] 
                 
                 
                   r 
                   = 
                   
                     r 
                     1 
                   
                 
               
             
           
         
       
     
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 36 and 37  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 44 and 45  are non-limiting exemplary plots of a first and a second transverse electric polar eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 46 and 47  are non-limiting exemplary plots of a first and a second transverse electric radial eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 48 and 49  are non-limiting exemplary plots of a first and a second transverse electric evanescent radial eigenfunction of a pyramidal cavity resonator, respectively. 
       FIG. 110  is an exemplary perspective view of a first transverse electric three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 111  is an exemplary perspective view of a first transverse electric three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 112  is an exemplary axial cross section view of a first electric field transverse electric density plot of a non-limiting pyramidal cavity resonator.  FIG. 113  is an exemplary axial cross section view of a first magnetic field transverse electric vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 118  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 119  is an exemplary radial cross section view of a first electric field transverse electric vector plot of a non-limiting truncated pyramidal resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 120  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 121  is an exemplary radial cross section view of a first magnetic field transverse electric vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting pyramidal cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from the base interior surface. 
     Example 8—Transverse Magnetic Wave Frequency of a Truncated Pyramidal Cavity Resonator 
     In some embodiments, a frequency of a hollow pyramidal cavity resonator is calculated per the equations below: 
     For an azimuthal eigenvalue (m) and a taper angle (φ 0 ) of the resonator: 
     
       
         
           
             
               m 
               = 
               
                 
                   
                     
                       n 
                       ⁢ 
                       π 
                     
                     
                       φ 
                       0 
                     
                   
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   where 
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   n 
                 
                 = 
                 0 
               
             
             , 
             1 
             , 
             2 
             , 
             … 
           
         
       
     
     For a polar eigenvalue (l), an azimuthal eigenvalue (m), a taper angle (θ 0 ), a polar wave equation (P l   m (cos θ)), and a polar wave equation (Q l   m (cos θ)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                     ⁢ 
                     
                       
                         Q 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           
                             - 
                             cos 
                           
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                   
                   - 
                   
                     
                       
                         P 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           
                             - 
                             cos 
                           
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                     ⁢ 
                     
                       
                         Q 
                         l 
                         m 
                       
                       ⁡ 
                       
                         ( 
                         
                           cos 
                           ⁢ 
                           
                             
                               θ 
                               0 
                             
                             2 
                           
                         
                         ) 
                       
                     
                   
                 
                 ] 
               
               
                 θ 
                 = 
                 
                   θ 
                   0 
                 
               
             
             = 
             0 
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
     
       
         
           
             
               
                 [ 
                 
                   
                     d 
                     
                       d 
                       ⁢ 
                       r 
                     
                   
                   ⁡ 
                   
                     [ 
                     
                       
                         ( 
                         kr 
                         ) 
                       
                       ⁢ 
                       
                         
                           h 
                           l 
                         
                         ⁡ 
                         
                           ( 
                           
                             k 
                             ⁢ 
                             r 
                           
                           ) 
                         
                       
                     
                     ] 
                   
                 
                 ] 
               
               
                 r 
                 = 
                 
                   r 
                   0 
                 
               
             
             = 
             
               
                 0 
                 ⁢ 
                 
                     
                 
                 ⁢ 
                 
                   
                     and 
                     ⁢ 
                     
                         
                     
                     [ 
                     
                       
                         d 
                         
                           d 
                           ⁢ 
                           r 
                         
                       
                       ⁡ 
                       
                         [ 
                         
                           
                             ( 
                             
                               k 
                               ⁢ 
                               r 
                             
                             ) 
                           
                           ⁢ 
                           
                             
                               h 
                               l 
                             
                             ⁡ 
                             
                               ( 
                               
                                 k 
                                 ⁢ 
                                 r 
                               
                               ) 
                             
                           
                         
                         ] 
                       
                     
                     ] 
                   
                   
                     r 
                     = 
                     
                       r 
                       1 
                     
                   
                 
               
               = 
               0 
             
           
         
       
     
     For a radial eigenvalue (k), a polar eigenvalue (l), a truncated radial length (r 0 ), a radial length (r 1 ), and a radial wave equation (h l (kr)) of the resonator: 
       [( kr ) h   l ( kr )] r=r     0   =0 or [( kr ) h   l ( kr )] r=r     1   =0 
     For a frequency (f), a radial eigenvalue (k), and a speed of light (c) of the resonator: 
     
       
         
           
             f 
             = 
             
               
                 k 
                 ⁢ 
                 c 
               
               
                 2 
                 ⁢ 
                 π 
               
             
           
         
       
     
       FIGS. 36 and 37  are non-limiting exemplary plots of a first and a second azimuthal eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 38 and 39  are non-limiting exemplary plots of a first and a second transverse magnetic polar eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 40 and 41  are non-limiting exemplary plots of a first and a second transverse magnetic radial eigenfunction of a pyramidal cavity resonator, respectively.  FIGS. 42 and 43  are non-limiting exemplary plots of a first and a second transverse magnetic evanescent radial eigenfunction of a pyramidal cavity resonator, respectively. 
       FIG. 86  is an exemplary perspective view of a first transverse magnetic three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 87  is an exemplary perspective view of a first transverse magnetic three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 88  is an exemplary axial cross section view of a first electric field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 89  is an exemplary axial cross section view of a first magnetic field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 94  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 95  is an exemplary radial cross section view of a first electric field transverse magnetic vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 96  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 97  is an exemplary radial cross section view of a first magnetic field transverse magnetic density plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 98  is an exemplary perspective view of a second transverse magnetic three-dimensional electric field vector plot of a non-limiting pyramidal cavity resonator.  FIG. 99  is an exemplary perspective view of a second transverse magnetic three-dimensional magnetic field vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 100  is an exemplary axial cross section view of a second electric field transverse magnetic density plot of a non-limiting pyramidal cavity resonator.  FIG. 101  is an exemplary axial cross section view of a second magnetic field transverse magnetic vector plot of a non-limiting pyramidal cavity resonator. 
       FIG. 106  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 107  is an exemplary radial cross section view of a second electric field transverse magnetic vector plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
       FIG. 108  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting truncated pyramidal cavity resonator.  FIG. 109  is an exemplary radial cross section view of a second magnetic field transverse magnetic density plot of a non-limiting truncated pyramidal cavity resonator comprising a substantially flat base and truncated interior surfaces. 
     As the size of the arrows in the above figures are positively correlated with an electric field and an electric field density, or with a magnetic field and a magnetic field density, the non-limiting pyramidal cavity resonator exhibits one or both a highly asymmetric electric field and a highly asymmetric electric field density, and a highly asymmetric magnetic field and a highly asymmetric magnetic field density, wherein the electric field and the electric field density, and the magnetic field and the magnetic field density, are more concentrated away from one or more of the at least three tapered interior surfaces and the truncated interior surface. 
     Terms and Definitions 
     Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. 
     As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. 
     As used herein, the term “about” refers to an amount that is near the stated amount by about 10%, 5%, or 1%, including increments therein. 
     The embodiments of the invention described above are intended to be merely exemplary; numerous variations and modifications will be apparent to those skilled in the art. Such variations and modifications are intended to be within the scope of the present invention as defined by any of the appended claims.