# PlanetPhysics/Physical Laws
## The Laws of Physics

This is a new contributed topic summarizing the laws of Physics.
more to come...

### Laws of Classical, Newtonian Mechanics

* Newton's first, second and third laws of motion
* Euler--Lagrange equation
* Conservation of momentum
* Conservation of mass and energy
* Newton's Law of Gravitation
* Hook's law

### Principles and Laws of Relativistic Mechanics

* Equivalence of reference systems or coordination frames
* Constancy of the speed of light, $c$
* Einstein's Equivalence of gravitational and inertial mass
* Einstein's Law of Mass-Energy Equivalence
* Einstein--Hilbert action
* Einstein's field equations (EFEs)
* Einstein--Maxwell equations
* Correspondence principle: Newton's law of gravitation derived from EFEs
* Mach's 'principle', or conjecture

### Laws of Fluids and Hydrodynamics

* 1
* 2
* 3

### Principle and Laws of Optics

* Maupertuis' Principle; Principle of Least (or minimum) Action; Variational principles
* Hamilton's Principle; Principle of Stationary Action
* Snell's Laws
* Huygens's Principle of Diffraction

### Laws of Electromagnetism and Electrodynamics

* charge Conservation
* Coulomb's law
* Amp\'ere's Law
* Faraday's Law
* Kirchhoff law for electrical circuits
* Maxwell's equations
* Bragg's Law
* Clausius-Mossotti Law
* xxxx

### Laws of Thermodynamics and Molecular Physics

* Energy Conservation
* Zeroth, First, Second and Third principles of thermodynamics: \bigbreak Zeroth Law -defines temperature: If a \htmladdnormallink{system {http://planetphysics.us/encyclopedia/SimilarityAndAnalogousSystemsDynamicAdjointnessAndTopologicalEquivalence.html} A is in thermal equilibrium with both systems B and C, then systems B and C are also in thermal equilibrium with each other; that is, if A is at the same temperature as both B and C, then B and C have to be at the same temperature, in thermal equilibrium with each other}. First Law: The change in a system's internal energy is equal to the difference between \htmladdnormallink{heat {http://planetphysics.us/encyclopedia/Heat.html} added to the system from its surroundings and work done by the system on its surroundings}; \bigbreak Second Law: In any process occurring in a \htmladdnormallink{closed system {http://planetphysics.us/encyclopedia/ThermodynamicLaws.html} the entropy can only increase}; \bigbreak Third Law: the entropy of any pure crystalline system tends to zero in the limit of temperature approaching zero absolute (i.e., in deg Kelvin) ; also Nernst's law or Nernst heat theorem.
* Avogadro's law: the number of \htmladdnormallink{molecules {http://planetphysics.us/encyclopedia/Molecule.html} or atoms in a specific volume of gas is a universal constant, independent of their size or the molecular mass of the gas}; a mol of gas contains always Avogadro's number, $N_{A}$, of molecules of the gas; $N_{A}=6.022\times 10^{23}mol^{-1}$.
* Clausius--Clapeyron equation
* Van't Hoff equation
* Henry's law: At constant temperature, the amount of a given gas dissolved in a given \htmladdnormallink{type {http://planetphysics.us/encyclopedia/Bijective.html} and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid}.
* Dalton's law (Dalton's law of partial pressures): The total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture .
* Van der Waals equation of state: Principle of Corresponding States
* Gibbs--Duhem equation , or the Phase Law
* Gibbs--Helmholtz equations
* Kopp's law for heat capacities
* Ehrenfest equations
* Maxwell's relations for Thermodynamic potentials
* Onsager's Principle; Onsager reciprocal relations
* Stefan--Boltzmann's Law
* Fick's laws of diffusion
* Maxwell---Stefan diffusion
* Churchill-Bernstein Equation
* Raoult's law
* Duhem--Margules equation
* Thermodynamics of black holes and spin networks in Qauntum Gravity

### Statistical Mechanics

* Maxwell--Boltzmann distribution laws:
* Maxwell---Boltzmann statistics,
* Bose--Einstein statistics,
* Ferm--Dirac statistics,
* Partition function and the Equations of State of a Thermodynamic System
* Schwinger functions and Osterwalder---Schrader theorem in statistical field theory
* Langevin equation

### Laws of Quantum Mechanics

* Planck's law and Universal constant, $h$
* Einstein's Laws of Light absorption and Emission; Einstein's coefficients
* Law of photoelectric effect
* Quantization Laws
* First and Second quantization Principles
* Correspondence Principle
* wave-particle duality (de Broglie)
* Superposition Principle and the quantum Wavefunction
* Uncertainty Principle (Heisenberg)
* Schr"/odinger's Equations
* Hamilton's Principle
* Einstein--Maxwell--Dirac equations (EMD)
* Klein--Fock--Gordon equation
* Rarita--Schwinger equation for spin--3/2 fermions
* Conservation Laws in Spontaneous and quantum measurement Processes
* Pauli's Principle for fermions
* Goldstone theorem
* Kirchhoff's Laws of spectroscopic analysis: Kirchhoff showed that there are three types of spectra emitted by objects: 1) Continuous spectrum -- a solid or liquid body radiates an uninterrupted, smooth spectrum (called a Planck curve); 2) Emission spectrum-- a radiating gas produces a spectrum of discrete spectral lines 3) Absorption spectrum -- a continuous spectrum that passes through a cool gas has specific spectral lines removed (inverse of an emission spectrum)
* Dispersion laws
* superconductivity principle and Meissner effect
* Wheeler--DeWitt equation in quantum gravity
Principles of \htmladdnormallink{quantum field theory {http://planetphysics.us/encyclopedia/SpaceTimeQuantizationInQuantumGravityTheories.html} (QFT) and quantum electrodynamics (QED)}
* particle Indistinguishability
* Second Quantization
* Mass--renormalization laws
* Schwinger--Dyson equation

### Laws of Atomic and Nuclear Physics

* Law of radioactive decay
* lepton conservation laws in electroweak theory
* The Standard Model
* supersymmetry
* Equivalence of string theories
* Symmetry Breaking and the Higgs theory Dispersion laws for Goldstone bosons
more to come ...