# Index of physics articles (U)

The index of physics articles is split into multiple pages due to its size.
To navigate by individual letter use the table of contents below.

## Index of physics articles

* 0–9
* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z

## U

* U-duality
* U.S. Standard Atmosphere
* UA1 experiment
* UA2 experiment
* UC Santa Barbara Physics Department
* UK Dark Matter Collaboration
* UMER
* UMIST linear system
* UNIT OF REFRIGERATION
* UPTI Affair
* USAF Stability and Control DATCOM
* UV completion
* UV fixed point
* Über die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten Teilchen
* Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen
* Udipi Ramachandra Rao
* Ugo Fano
* Ukichiro Nakaya
* Ulf Leonhardt
* Ultimate fate of the universe
* Ultra-high-energy cosmic ray
* Ultra-low frequency
* Ultra high frequency
* Ultrafast x-rays
* Ultrahigh energy gamma-ray
* Ultralight trike
* Ultraluminous X-ray source
* Ultramicroscope
* Ultrarelativistic limit
* Ultrashort pulse
* Ultrasoft radiation
* Ultrasonic flow meter
* Ultrasonic foil (papermaking)
* Ultrasonic force microscopy
* Ultrasonic hearing
* Ultrasonic horn
* Ultrasonic nozzle
* Ultrasonic sensor
* Ultrasonic testing
* Ultrasonic welding
* Ultrasonics
* Ultrasound
* Ultrasound-enhanced systemic thrombolysis
* Ultrasound attenuation spectroscopy
* Ultraviolet
* Ultraviolet catastrophe
* Ultraviolet divergence
* Umklapp scattering
* Unbiennium
* Uncertainty
* Uncertainty principle
* Unconventional wind turbines
* Undercompressive shock wave
* Understanding Physics
* Undertow (wave action)
* Underwater acoustic communication
* Underwater acoustic positioning system
* Underwater acoustics
* Underwater telephone
* Undulation of the geoid
* Undulator
* Undulatory theory of light
* Unequal rotor lift distribution
* Uniaxial crystal
* Unified field theory
* Uniform acceleration
* Uniform circular motion
* Uniform motion
* Uniform theory of diffraction
* Uniqueness theorem for Poisson's equation
* Unit commensurability
* Unit of length
* Unitarity (physics)
* Unitarity bound
* Unitarity gauge
* Unitary Plan Wind Tunnel
* United States Air Force Stability and Control Digital DATCOM
* United States Invitational Young Physicists Tournament
* United States National Physics Olympiad
* United States gravity control propulsion research
* Units of measurement
* Universal conductance fluctuations
* Universal extra dimension
* Universal force field
* Universal linear accelerator
* Universal quantum simulator
* Universal wavefunction
* Universality (dynamical systems)
* Universe
* Unparticle physics
* Unrestricted Hartree–Fock
* Unruh effect
* Unruh temperature
* Unsepttrium
* Unsolved problems in astronomy
* Untriseptium
* Up quark
* Upper-atmospheric lightning
* Upper-convected Maxwell model
* Upper-convected time derivative
* Upper critical solution temperature
* Upper hybrid oscillation
* Upper tangent arc
* Upsilon meson
* Upward continuation
* Upward looking sonar
* Upwind scheme
* Uranium
* Uranium boride
* Uranium carbide
* Uranium dioxide
* Uranium hydride bomb
* Uranium in the environment
* Uranium pentafluoride
* Uranium tetrachloride
* Uranium tetrafluoride
* Uranyl carbonate
* Uranyl nitrate
* Uranyl peroxide
* Urca process
* Uriel Frisch
* Ursell number
* Ursula Franklin
* Uspekhi Fizicheskikh Nauk
* Ussing chamber
* Uzi Landman