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.
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OECC OPAL detector OPERA experiment OSA Fellow OSO 3 OSO 7 OVRO 40 meter Telescope OZI Rule Oak Ridge National Laboratory Oberth effect Objective (optics) Oblique correction Oblique shock Oblique wing Observable Observable universe Observational cosmology Observer (general relativity) Observer (quantum physics) Observer (special relativity) Observer effect (physics) Ocean gyre Ocean thermal energy conversion Oceanography Ocellus Lucanus Octavio Novaro Odd molecule Odd sympathy Oersted Oersted Medal Ofer Biham Ofer Lahav Off-axis optical system Oganesson Ogden Rood Ohm Ohm's law Ohmic contact Ohnesorge number Oil drop experiment Okorokov effect Ola Hunderi Olaf Dreyer Olami–Feder–Christensen model Olav Holt Olbers' paradox Old quantum theory Oldroyd-B model Ole Jacob Broch Oleg D. Jefimenko Oleg Firsov Oleg Losev Oleg Sushkov Olexander Smakula Olga Kennard Olinto De Pretto Oliver E. Buckley Condensed Matter Prize Oliver Heaviside Oliver Lodge Olli Lounasmaa Olympia Academy Omega baryon Omega meson On-Line Isotope Mass Separator On Physical Lines of Force On shell and off shell On the Shoulders of Giants (book) On the movement of small particles suspended in a stationary liquid demanded by the molecular-kinetic theory of heat One-electron universe One-loop Feynman diagram One-way speed of light Onium Online refuelling Onsager reciprocal relations Onset of deconfinement Oops-Leon Oort constants Opacity (optics) Opalescence Open-pool Australian lightwater reactor OpenFOAM OpenScientist Open Source Physics Open quantum system Open shell Operator (physics) Operator product expansion Oppenheimer–Phillips process Optic crystals Optical Fiber Technology Optical Gravitational Lensing Experiment Optical Physics Optical Review Optical Society Optical Society of Japan Optical aberration Optical amplifier Optical autocorrelation Optical axis Optical black hole Optical brightener Optical cavity Optical chopper Optical circulator Optical coating Optical coherence tomography Optical communication Optical conductivity Optical contact bonding Optical depth Optical downconverter Optical equivalence theorem Optical feedback Optical field Optical flat Optical force Optical format Optical lattice Optical lens design Optical levitation Optical medium Optical metamaterial Optical microsphere Optical modulator Optical modulators using semiconductor nano-structures Optical neural network Optical parametric amplifier Optical parametric oscillator Optical path Optical path length Optical phenomenon Optical phonon Optical physics Optical power Optical properties of carbon nanotubes Optical pulsar Optical pumping Optical reader Optical rectification Optical ring resonators Optical rotatory dispersion Optical scalars Optical science Optical sciences Optical sectioning Optical sine theorem Optical superresolution Optical switch Optical telescope Optical theorem Optical train Optical transition radiation Optical tweezers Optical window Optically stimulated luminescence Opticks Optics Optics & Photonics News Optics (physics) Optics Classification and Indexing Scheme Optics Communications Optics Express Optics Letters Optics and Photonics News Optics and Spectroscopy Optik (journal) Optoelectric nuclear battery Optoelectronics Optofluidics Optomechanics Orb (optics) Orbit Orbit (dynamics) Orbit equation Orbit phasing Orbital angular momentum multiplexing Orbital angular momentum of light Orbital decay Orbital eccentricity Orbital elements Orbital inclination Orbital integral Orbital mechanics Orbital motion Orbital motion (quantum) Orbital node Orbital period Orbital plane (astronomy) Orbital state vectors Orbiting body Orbitrap Ordal Demokan Order and disorder (physics) Order operator Ordered exponential Orders of magnitude (charge) Orders of magnitude (density) Orders of magnitude (energy) Orders of magnitude (entropy) Orders of magnitude (force) Orders of magnitude (length) Orders of magnitude (luminous flux) Orders of magnitude (magnetic field) Orders of magnitude (mass) Orders of magnitude (power) Orders of magnitude (pressure) Orders of magnitude (radiation) Orders of magnitude (resistance) Orders of magnitude (specific energy density) Orders of magnitude (specific heat capacity) Orders of magnitude (temperature) Orders of magnitude (voltage) Orest Khvolson Oreste Piccioni Orfeu Bertolami Organic field-effect transistor Organic nonlinear optical materials Organic photorefractive materials Organic superconductor Orientifold Orifice plate Origin of avian flight Ornstein–Zernike equation Orr–Sommerfeld equation Orso Mario Corbino OrthoCAD Network Research Cell Orthobaric density Orthometric height Orthomode transducer Orthorhombic crystal system Orthovoltage X-rays Osborne Reynolds Oscar Lanford Oscar Sala Oscar W. Greenberg Oscillation Oscillator linewidth Oscillator phase noise Oscillatory universe Oscillon Osculating orbit Oseen's approximation Oseen equations Oskar Heil Oskar Klein Oskar Klein Memorial Lecture Oskar Ritter Osmosis Osoaviakhim-1 Ostro Ostwald ripening Ostwald–Freundlich equation Otoacoustic emission Ottaviano-Fabrizio Mossotti Otto Bastiansen Otto Hahn Otto Haxel Otto Klemperer (physicist) Otto Kratky Otto Laporte Otto Laporte Award Otto Lehmann (physicist) Otto Lummer Otto Robert Frisch Otto Scherzer Otto Schmitt Otto Stern Otto Wiener (physicist) Otto cycle Otto von Guericke Otto Øgrim Our Mr. Sun Outdoor–indoor transmission class Outflow channels Outhouse (unit) Outline of applied physics Outline of astronomy Outline of geophysics Outline of physical science Outline of physics Ouzo effect Over/under cable coiling Overflow (software) Overlap matrix Overtone Owen Chamberlain Owen Willans Richardson Oxford Calculators Oxford Electric Bell Oxide thin-film transistor Oxsensis Oxygen-burning process Oxygen permeability Oyo Buturi Øyvind Grøn Ozsváth–Schücking metric