# Index of physics articles (R)

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

## R

* R-factor (crystallography)
* R-hadron
* R-parity
* R-process
* R-symmetry
* R. A. Stradling
* R. Orin Cornett
* R. S. Krishnan
* R. Stanley Williams
* R. Stephen Berry
* R136a1
* R1 (nuclear reactor)
* R4 nuclear reactor
* RA-1 Enrico Fermi
* RC time constant
* RF antenna ion source
* RHEED-TRAXS
* RKKY interaction
* RNS formalism
* ROI PAC
* ROOT
* RRKM theory
* RT (energy)
* RX J0806.3+1527
* R (cross section ratio)
* RaLa Experiment
* Rabbit (nuclear engineering)
* Rabi cycle
* Rabi frequency
* Rabi problem
* Radial distribution function
* Radial motion
* Radial polarization
* Radial velocity
* Radian per second
* Radian per second squared
* Radiance
* Radiant barrier
* Radiant energy
* Radiant flux
* Radiant intensity
* Radiation
* Radiation-dominated era
* Radiation chemistry
* Radiation damping
* Radiation flux
* Radiation hormesis
* Radiation impedance
* Radiation implosion
* Radiation intelligence
* Radiation length
* Radiation material science
* Radiation monitoring
* Radiation pressure
* Radiation protection
* Radiation scattering
* Radiation stress
* Radiation trapping
* Radiational cooling
* Radiative cooling
* Radiative equilibrium
* Radiative heat transfer
* Radiative process
* Radiative transfer
* Radio-frequency induction
* Radio-frequency quadrupole
* Radio Ice Cerenkov Experiment
* Radio astronomy
* Radio frequency
* Radio galaxy
* Radio noise source
* Radio occultation
* Radio spectrum pollution
* Radio waves
* Radio window
* Radioactive Substances Act 1993
* Radioactive decay
* Radioactive displacement law of Fajans and Soddy
* Radioactive waste
* Radioanalytical chemistry
* Radiobiology
* Radiochemistry
* Radiodensity
* Radiogenic nuclide
* Radiographic equipment
* Radiography
* Radiohalo
* Radioisotope piezoelectric generator
* Radioisotope thermoelectric generator
* Radioluminescence
* Radiometer
* Radiometric dating
* Radiometry
* Radion (physics)
* Radiophysics
* Radioscope
* Radiosity (heat transfer)
* Radium and radon in the environment
* Radius of curvature (optics)
* Radius of gyration
* Rafael Bruschweiler
* Rafael Ghazaryan
* Rafael Sorkin
* Rahul Mahajan (blogger)
* Rainbow
* Rainbow hologram
* Rainer Blatt
* Rainout (radioactivity)
* Raja Ramanna
* Rajaram Nityananda
* Rajesh Gopakumar
* Rajnath Singh
* Ralph A. Sawyer
* Ralph Asher Alpher
* Ralph H. Fowler
* Ralph Kronig
* Ralph Lapp
* Ralph Pudritz
* Ralph von Frese
* Ram pressure
* Rama Bansil
* Ramamurti Shankar
* Raman Prinja
* Raman Sundrum
* Raman laser
* Raman microscope
* Raman scattering
* Ramanuja Vijayaraghavan
* Rammal Rammal
* Ramond sector
* Ramond–Ramond field
* Ramsauer–Townsend effect
* Randall J. LeVeque
* Randall–Sundrum model
* Random close pack
* Random energy model
* Random laser
* Random matrix
* Random phase approximation
* Range (particle radiation)
* Rangefinder
* Rankine cycle
* Rankine vortex
* Rankine–Hugoniot conditions
* Raoul Franklin
* Raoul Pictet
* Raoult's law
* Raphael Tsu
* Rapid phase transition
* Rapid single flux quantum
* Rapidity
* Rare-earth magnet
* Rare Earth hypothesis
* Rare Isotope Accelerator
* Rare Symmetry Violating Processes
* Rarefaction
* Rarita-Schwinger action
* Rarita–Schwinger equation
* Rashba effect
* Rashid Sunyaev
* Rate of heat flow
* Rational conformal field theory
* Raul Rabadan
* Ravi Grover
* Ray (optics)
* Ray Kidder
* Ray Mackintosh
* Ray Streater
* Ray tracing (physics)
* Ray transfer matrix analysis
* Raychaudhuri equation
* Rayleigh distance
* Rayleigh flow
* Rayleigh law
* Rayleigh number
* Rayleigh scattering
* Rayleigh–Bénard convection
* Rayleigh–Gans approximation
* Rayleigh–Jeans law
* Rayleigh–Plesset equation
* Rayleigh–Taylor instability
* Raymond Chiao
* Raymond Davis, Jr.
* Raymond Gosling
* Raymond Herb
* Raymond Hide
* Raymond Jeanloz
* Raymond L. Orbach
* Raymond Seeger
* Raymond Thayer Birge
* Raynor Johnson
* Raziuddin Siddiqui
* Reactimeter
* Reaction (physics)
* Reaction coordinate
* Reaction field method
* Reactionless drive
* Reaction–diffusion–advection equation
* Reactive centrifugal force
* Reactor-grade plutonium
* Reactor Experiment for Neutrino Oscillation
* Reactor building
* Reactor protection system
* Reactor vessel
* Real-is-positive convention
* Real-time Neutron Monitor Database
* Real gas
* Real neutral particle
* Rear flank downdraft
* Reber Radio Telescope
* Received noise power
* Receiver (modulated ultrasound)
* Reciprocal lattice
* Reciprocal space
* Reciprocating oscillation
* Reciprocity (electrical networks)
* Reciprocity (electromagnetism)
* Recoil temperature
* Recombination (cosmology)
* Rectangular potential barrier
* Rectilinear lens
* Rectilinear propagation
* Recuperator
* Recurrence plot
* Recurrence quantification analysis
* Red adaptation goggles
* Red clump
* Red dwarf
* Redlich–Kwong equation of state
* Redshift
* Redshift quantization
* Redshift survey
* Reduced mass
* Reduced moderation water reactor
* Reduced pressure
* Reduced properties
* Reduced temperature
* Reduction criterion
* Reed Research Reactor
* Reeh–Schlieder theorem
* Reentrant superconductivity
* Reference beam
* Reference noise
* Reference surface
* Reflectin
* Reflection (physics)
* Reflection coefficient
* Reflection high-energy electron diffraction
* Reflections on the Motive Power of Fire
* Reflectivity
* Reflectometric interference spectroscopy
* Refraction
* Refractive index
* Refractive index contrast
* Refractive indices
* Refrigeration
* Refrigerator
* Regelation
* Regenerative amplification
* Regenerative fuel cell
* Regge calculus
* Regge theory
* Reginald Victor Jones
* Regnier de Graaf
* Regularization (physics)
* Reimar Lüst
* Reiner Kruecken
* Reinhard Meinel
* Reinhard Oehme
* Reinhold Bertlmann
* Reinhold Ewald
* Reinhold Mannkopff
* Reionization
* Reissner–Nordström metric
* Relation between Schrödinger's equation and the path integral formulation of quantum mechanics
* Relational quantum mechanics
* Relational theory
* Relationship between string theory and quantum field theory
* Relative angular momentum
* Relative density
* Relative humidity
* Relative intensity noise
* Relative locality
* Relative permeability
* Relative permittivity
* Relative pressure
* Relative velocity
* Relative viscosity
* Relative wind
* Relativistic Breit–Wigner distribution
* Relativistic Doppler effect
* Relativistic Euler equations
* Relativistic Heavy Ion Collider
* Relativistic aberration
* Relativistic beaming
* Relativistic dynamics
* Relativistic electromagnetism
* Relativistic electron beam
* Relativistic heat conduction
* Relativistic jet
* Relativistic mechanics
* Relativistic nuclear collisions
* Relativistic particle
* Relativistic plasma
* Relativistic quantum chemistry
* Relativistic similarity parameter
* Relativistic speed
* Relativistic wave equations
* Relativity: The Special and the General Theory
* Relativity of simultaneity
* Relativity priority dispute
* Relaxation (NMR)
* Relaxation (physics)
* Relaxation length
* Relaxed stability
* Relaxometry
* Relic particles
* Religious views of Albert Einstein
* Reluctance
* Remanence
* Remission (spectroscopy)
* Remo Ruffini
* Remote plasma
* Remote sensing
* Renata Kallosh
* Renate Loll
* Renewable energy
* Renewable energy debate
* Renninger negative-result experiment
* Renormalizable
* Renormalization
* Renormalization group
* Renormalon
* Replica trick
* Reports on Progress in Physics
* Representation theory of the Galilean group
* Representation theory of the Poincaré group
* Reprocessed uranium
* Reptation Monte Carlo
* Research Letters in Physics
* Research reactor
* Residual chemical shift anisotropy
* Residual entropy
* Residual flux density
* Residual gas analyzer
* Residual property (physics)
* Residual strength
* Residual stress
* Resilience
* Resist
* Resistance distance
* Resistive skin time
* Resolved sideband cooling
* Resonance
* Resonance (particle)
* Resonance (particle physics)
* Resonance chamber
* Resonance disaster
* Resonant inelastic X-ray scattering
* Resonant magnetic perturbations
* Resonating valence bond theory
* Resonator
* Response reactions
* Resputtering
* Rest (physics)
* Rest energy
* Rest frame
* Restoring force
* Restricted open-shell Hartree–Fock
* Resultant tone
* Resummation
* Retarded position
* Retarded potential
* Retarded time
* Retentivity
* Retreating blade stall
* Retrocausality
* Retroflect
* Retrograde condensation
* Retrogression heat treatment
* Revaz Dogonadze
* Reverberation
* Reverberation chamber
* Reverberation room
* Reverse diffusion
* Reverse leakage current
* Reverse phase velocity
* Reverse phasevelocity
* Reversed field pinch
* Reversible dynamics
* Reversible process (thermodynamics)
* Reversible reference system propagation algorithm
* Reversing thermometer
* Review of Scientific Instruments
* Reviews of Geophysics
* Reviews of Modern Physics
* Reyn
* Reynolds-averaged Navier–Stokes equations
* Reynolds decomposition
* Reynolds number
* Reynolds operator
* Reynolds stress
* Reynolds transport theorem
* Reza Mansouri
* Rheology
* Rheometer
* Rheometry
* Rheonomous
* Rheopecty
* Rheoscope
* Rheoscopic fluid
* Rho meson
* Rhombohedral lattice system
* Riabouchinsky solid
* Riazuddin (physicist)
* Riccardo Giacconi
* Ricci calculus
* Ricci curvature
* Ricci decomposition
* Richard A. Muller
* Richard Arnowitt
* Richard Becker (physicist)
* Richard Beeching, Baron Beeching
* Richard Bolt
* Richard C. Lord
* Richard C. Powell
* Richard C. Tolman
* Richard Christopher Carrington
* Richard Clegg
* Richard D. Gill
* Richard D. James (scientist)
* Richard D. Leapman
* Richard Dalitz
* Richard Davisson
* Richard Dixon Oldham
* Richard Duffin
* Richard E. Berendzen
* Richard E. Hayden
* Richard E. Taylor
* Richard Ellis (astronomer)
* Richard Epp (physicist)
* Richard Ernest Kronauer
* Richard F. Post
* Richard Feynman
* Richard Franklin Humphreys
* Richard Friend
* Richard G. Compton
* Richard Gans
* Richard Garwin
* Richard Gill (physicist)
* Richard Glazebrook
* Richard H. Price
* Richard J. Gambino
* Richard K. Yamamoto
* Richard Keith Ellis
* Richard L. Abrams
* Richard Liboff
* Richard Lindzen
* Richard M. Weiner
* Richard Makinson
* Richard Massey
* Richard Mollier
* Richard P.A.C. Newman
* Richard P. Turco
* Richard Schoen
* Richard Scott Perkin
* Richard Sears McCulloh
* Richard Sillitto
* Richard T. Whitcomb
* Richard Threlkeld Cox
* Richard W. Ziolkowski
* Richard Wolfson (physicist)
* Richard von Mises
* Richards equation
* Richardson number
* Richtmyer–Meshkov instability
* Ricky J Sethi
* Ridge lift
* Ridged mirror
* Ridley–Watkins–Hilsum theory
* Riemann curvature tensor
* Riemann solver
* Riemann tensor (general relativity)
* Riemannian Penrose inequality
* Riemann–Silberstein vector
* Rietdijk–Putnam argument
* Rietveld refinement
* Riggatron
* Right-hand rule
* Right hand grip rule
* Rigid-body kinematics
* Rigid body
* Rigid body dynamics
* Rigid rotor
* Rijke tube
* Rindler coordinates
* Ring-imaging Cherenkov detector
* Ring current
* Ring laser
* Ring laser gyroscope
* Ring singularity
* Ring wave guide
* Rip current
* Ripple (electrical)
* Rise over thermal
* Rishon model
* Ritz method
* Rivista del Nuovo Cimento
* Roald Sagdeev
* Rob Adam
* Robbert Dijkgraaf
* Robert A. Woodruff
* Robert Adair (physicist)
* Robert Alfano
* Robert Andrews Millikan
* Robert Arns
* Robert Aymar
* Robert Ayres (scientist)
* Robert B. Laughlin
* Robert B. Leighton
* Robert Bacher
* Robert Bindschadler
* Robert Blinc
* Robert Boyle
* Robert Brout
* Robert Bruce Lindsay
* Robert C. Duncan (astrophysicist)
* Robert C. Dynes
* Robert Coleman Richardson
* Robert Corey
* Robert Cornog
* Robert D. Maurer
* Robert D. Richtmyer
* Robert Delbourgo
* Robert Dunkin
* Robert Döpel
* Robert E. Hopkins
* Robert E. Vardeman
* Robert Edward Bell
* Robert Emden
* Robert F. Beck
* Robert F. Christy
* Robert Fischell
* Robert G. Chambers
* Robert G. Greenler
* Robert G. Shulman
* Robert Geroch
* Robert Griffiths (physicist)
* Robert H. Dicke
* Robert H. Lieberman
* Robert H. Williams (physicist)
* Robert Haynes
* Robert Herman
* Robert Hofstadter
* Robert Hooke
* Robert J. Birgeneau
* Robert J. Lang
* Robert J. Van de Graaff
* Robert Jaffe (physicist)
* Robert K. Logan
* Robert Karplus
* Robert Kirby-Harris
* Robert Kraichnan
* Robert L. Byer
* Robert L. Forward
* Robert L. Hurt
* Robert L. Park
* Robert Leigh (physicist)
* Robert Lin
* Robert Lyster Thornton
* Robert M. L. Baker, Jr.
* Robert Mallet
* Robert Marshak
* Robert Matthews (scientist)
* Robert Mills (physicist)
* Robert Morris Page
* Robert Myers (physicist)
* Robert Norman
* Robert Noyce
* Robert Ochsenfeld
* Robert P. Madden
* Robert Parr
* Robert Pohl
* Robert Pound
* Robert R. Shannon
* Robert R. Wilson
* Robert Resnick
* Robert Retherford
* Robert Rosner
* Robert Russell Newton
* Robert S. Mulliken
* Robert S. Shankland
* Robert Shaw (physicist)
* Robert Sproull
* Robert Strutt, 4th Baron Rayleigh
* Robert Thomas Jones (engineer)
* Robert T. Siegel
* Robert W. Bower
* Robert W. Boyd
* Robert W. Bussard
* Robert W. Wood
* Robert Wald
* Robert Were Fox the Younger
* Robert William Boyle
* Robert Woodrow Wilson
* Robert von Lieben
* Roberto Abraham
* Roberto Car
* Roberto Merlin
* Roberto Peccei
* Roberto Salmeron
* Roberval balance
* Robijn Bruinsma
* Robin Devenish
* Robinson oscillator
* Robinson–Dadson curves
* Robley C. Williams
* Robot kinematics
* Robotic telescope
* Roche limit
* Rochon prism
* Rock magnetism
* Rocket engine nozzle
* Rocket glider
* Rod C. Alferness
* Rod Crewther
* Rod Cross
* Roddam Narasimha
* Roderich Moessner
* Rodney Baxter
* Rodney Cotterill
* Rodney Jory
* Rodney Marks (astrophysicist)
* Rodney S. Ruoff
* Rodolfo Gambini
* Roe solver
* Roentgen (unit)
* Roentgen equivalent man
* Rogallo wing
* Roger Balian
* Roger Cashmore
* Roger Cowley
* Roger Penrose
* Roger Temam
* Rogue wave
* Roland Benz
* Roland Dobbs
* Roland Dobrushin
* Roland Hüttenrauch
* Roland Omnès
* Roland W. Schmitt
* Rolf-Dieter Heuer
* Rolf Hagedorn
* Rolf Landauer
* Rolf Maximilian Sievert
* Rolf Michel
* Rolf Widerøe
* Roll center
* Roll moment
* Rollin film
* Rolling
* Rolling ball argument
* Rolling cone motion
* Rolling resistance
* Roman Jackiw
* Roman Ulrich Sexl
* Roman pot
* Roman ring
* Ronald Collé
* Ronald Drever
* Ronald E. Cohen
* Ronald Ernest Aitchison
* Ronald F. Probstein
* Ronald Fedkiw
* Ronald Kantowski
* Ronald McNair
* Ronald N. Bracewell
* Ronald Rivlin
* Ronald W. Gurney
* Ronald W. Yeung
* Ronnie Bell
* Ronold W. P. King
* Room-temperature superconductor
* Room acoustics
* Room temperature
* Root-mean-square speed
* Roothaan equations
* Roper resonance
* Rosalind Franklin
* Rosalyn Sussman Yalow
* Rosatom
* Rosemary Wyse
* Roshko number
* Ross H. McKenzie
* Rossby number
* Rossby wave
* Rossiter–McLaughlin effect
* Roswell Clifton Gibbs
* Rotameter
* Rotating black hole
* Rotating furnace
* Rotating radio transient
* Rotating reference frame
* Rotating spheres
* Rotating tank
* Rotating wave approximation
* Rotation
* Rotation-powered pulsar
* Rotation around a fixed axis
* Rotation number
* Rotation operator (quantum mechanics)
* Rotational Brownian motion
* Rotational diffusion
* Rotational energy
* Rotational invariance
* Rotational motion
* Rotational speed
* Rotational temperature
* Rotational transition
* Rotational–vibrational coupling
* Roton
* Rotordynamics
* Rotor–stator interaction
* Rouse model
* Rouse number
* Route dependence
* Routhian
* Rovibrational coupling
* Rovibronic coupling
* Rowland ring
* Roy J. Glauber
* Roy Kerr
* Roy McWeeny
* Roy Sambles
* Roy Schwitters
* Royal Astronomical Society
* Rp-process
* Ruark number
* Rubber elasticity
* Rubens tube
* Rubidium standard
* Ruby Payne-Scott
* Ruby laser
* Rudder ratio
* Rudolf Clausius
* Rudolf Fleischmann
* Rudolf Grimm
* Rudolf Haag
* Rudolf Kingslake
* Rudolf Kohlrausch
* Rudolf Kompfner
* Rudolf Ladenburg
* Rudolf Luneburg
* Rudolf M. Tromp
* Rudolf Mössbauer
* Rudolf Peierls
* Rudolf Podgornik
* Rudolf Schulten
* Rudolf Seeliger
* Rudolf Tomaschek
* Rudolph Koenig
* Rudolph Schild
* Ruggero Santilli
* Rui-Ming Xu
* Rumble (noise)
* Runaway breakdown
* Rush D. Holt, Jr.
* Rushbrooke inequality
* Russell Alan Hulse
* Russell Stannard
* Russell Targ
* Russell–Einstein Manifesto
* Rustle noise
* Rutherford backscattering spectrometry
* Rutherford cable
* Rutherford model
* Rutherford scattering
* Rydberg atom
* Rydberg constant
* Rydberg formula
* Rydberg matter
* Rydberg molecule
* Rydberg state
* Rydberg–Klein–Rees method
* Rydberg–Ritz combination principle
* Ryogo Kubo
* Rytov number
* Rényi entropy
* Rømer's determination of the speed of light