Physics
Physics (from the
Greek, φύσις (
phúsis), "nature" and φυσικός (
phusikós), "natural"), the most fundamental
physical science, is concerned with the underlying principles of the
natural world. Consequently, physics deals with the elementary constituents of the
Universe and their
interactions, as well as the analysis of systems which are best understood in terms of these fundamental principles.
Discoveries in physics find applications throughout the other
natural sciences as they regard the basic constituents of the Universe. Some of the phenomena studied in physics, such as the phenomenon of
conservation of energy, are common to
all material systems. These are often referred to as
laws of physics. Others, such as
superconductivity, stem from these laws, but are not laws themselves because they only appear in some systems. Physics is often said to be the "fundamental science" (chemistry is sometimes included), because each of the other sciences (
biology,
chemistry,
geology,
material science,
engineering,
medicine etc.) deals with particular types of material systems that obey the laws of physics. For example, chemistry is the science of matter (such as
atoms and
molecules) and the
chemical substances that they form in the bulk. The structure, reactivity, and properties of a
chemical compound are determined by the properties of the underlying molecules, which can be described by areas of physics such as
quantum mechanics (called in this case
quantum chemistry),
thermodynamics, and
electromagnetism.
(Refer to Branches of physics)Physics is closely related to
mathematics, which provides the logical framework in which physical laws can be precisely formulated and their predictions quantified. Physical
definitions,
models and
theories are invariably expressed using mathematical relations. A key difference between physics and mathematics is that because physics is ultimately concerned with descriptions of the material world, it tests its
theories by
observations (called
experiments), whereas mathematics is concerned with abstract logical patterns not limited by those observed in the real world (because the real world is limited in the number of dimensions and in many other ways it does not have to correspond to richer mathematical structures). The distinction, however, is not always clear-cut. There is a large area of research intermediate between physics and mathematics, known as
mathematical physics.
Physics attempts to describe the natural world by the application of the
scientific method.
Natural philosophy, its counterpart, is the study of the changing world by philosophy which has been also called "physics" since classical times to at least up to its separation from philosophy as a
positive science in the 19th century. Mixed questions, of which solutions can be attempted through the applications of both disciplines (e.g. the divisibility of the atom) can involve natural philosophy in physics the science and vice versa.
Since the construction of
quantum mechanics in the early twentieth century, it generally became evident to the physical community that it would be preferable for every known description of
Nature to be
quantized, that is, to follow the
postulates of quantum mechanics. To this effect, all results that were not quantized are called
classical: this includes the
special and general theories of relativity. Simply because a result is classical does not mean that it was discovered before the advent of quantum mechanics. Classical theories are, generally, much easier to work with and much research is still being conducted on them without the express aim of quantization. However, there exist problems in physics in which classical and quantum aspects must be combined to attain some appoximation or limit that may acquire several forms as the passage from classical to quantum mechanics is often difficult — such problems are termed
semiclassical.
However, because relativity and quantum mechanics provide the most complete known description of fundamental interactions, and because the changes brought by these two frameworks to the physicist's world view were revolutionary, the term
modern physics is used to describe physics which relies on these two theories. Colloquially, modern physics can be described as the physics of extremes: from systems at the extremely small (
atoms,
nuclei,
fundamental particles) to the extremely large (the
Universe) and of the extremely fast (
relativity).
|
Classification of physics fields by the types of effects that need to be accounted for |
Physicists study a wide range of physical phenomena, from
quarks to
black holes, from individual
atoms to the many-body systems of
superconductors.
Central theories
While physics deals with a wide variety of systems, there are certain theories that are used by all physicists. Each of these theories were experimentally tested numerous times and found correct as an approximation of Nature (within a certain domain of validity). For instance, the theory of
classical mechanics accurately describes the motion of objects, provided they are much larger than
atoms and moving at much less than the
speed of light. These theories continue to be areas of active research; for instance, a remarkable aspect of classical mechanics known as
chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by
Isaac Newton (
1642"
1727). These "central theories" are important tools for research into more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in them.
| Concepts | | Classical mechanics | Newton's laws of motion, Lagrangian mechanics, Hamiltonian mechanics, Kinematics, Statics, Dynamics, Chaos theory, Acoustics, Fluid dynamics, Continuum mechanics | Density, Dimension, Gravity, Space, Time, Motion, Length, Position, Velocity, Acceleration, Mass, Momentum, Force, Energy, Angular momentum, Torque, Conservation law, Harmonic oscillator, Wave, Work, Power, Harmonic oscillator |
| Electromagnetism | Electrostatics, Electrodynamics, Electricity, Magnetism, Maxwell's equations, Optics | Capacitance, Electric charge, Current, Electrical conductivity, Electric field, Electric permittivity, Electrical resistance, Electromagnetic field, Electromagnetic induction, Electromagnetic radiation, Gaussian surface, Magnetic field, Magnetic flux, Magnetic monopole, Magnetic permeability |
| Thermodynamics and Statistical mechanics | Heat engine, Kinetic theory | Boltzmann's constant, Conjugate variables, Enthalpy, Entropy, Equation of state, Equipartition theorem, Free energy, Heat, Ideal gas law, Internal energy, Laws of thermodynamics, Irreversible process, Partition function, Pressure, Reversible process, Spontaneous process, State function, Statistical ensemble, Temperature, Thermodynamic equilibrium, Thermodynamic potential, Thermodynamic processes, Thermodynamic state, Thermodynamic system, Viscosity |
| Quantum mechanics | Path integral formulation, Scattering theory, Schrödinger equation, Quantum field theory, Quantum statistical mechanics | Adiabatic approximation, Correspondence principle, Free particle, Hamiltonian, Hilbert space, Identical particles, Matrix Mechanics, Planck's constant, Operators, Quanta, Quantization, Quantum entanglement, Quantum harmonic oscillator, Quantum number, Quantum tunneling, Schrödinger's cat, Dirac equation, Spin, Wavefunction, Wave mechanics, Wave-particle duality, Zero-point energy, Pauli Exclusion Principle, Heisenberg Uncertainty Principle |
| Theory of relativity | Special relativity, General relativity, Einstein field equations | Covariance, Einstein manifold, Equivalence principle, Four-momentum, Four-vector, General principle of relativity, Geodesic motion, Gravity, Gravitoelectromagnetism, Inertial frame of reference, Invariance, Length contraction, Lorentzian manifold, Lorentz transformation, Metric, Minkowski diagram, Minkowski space, Principle of Relativity, Proper length, Proper time, Reference frame, Rest energy, Rest mass, Relativity of simultaneity, Spacetime, Special principle of relativity, Speed of light, Stress-energy tensor, Time dilation, Twin paradox, World line |
Major fields of physics
Contemporary research in physics is divided into several distinct fields that study different aspects of the material world.
Condensed matter physics, by most estimates the largest single field of physics, is concerned with how the properties of bulk matter, such as the ordinary
solids and
liquids we encounter in everyday life, arise from the properties and mutual interactions of the constituent atoms. The field of
atomic, molecular, and optical physics deals with the behavior of individual atoms and molecules, and in particular the ways in which they absorb and emit
light. The field of
particle physics, also known as "high-energy physics", is concerned with the properties of submicroscopic particles much smaller than atoms, including the
elementary particles from which all other units of matter are constructed. Finally, the field of
astrophysics applies the laws of physics to explain
celestial phenomena, ranging from the
Sun and the other objects in the
solar system to the Universe as a whole.
Since the
20th century, the individual fields of physics have become increasingly
specialized, and nowadays it is not uncommon for physicists to work in a single field for their entire careers. "Universalists" like
Albert Einstein (
1879"
1955) and
Lev Landau (
1908"
1968), who were comfortable working in multiple fields of physics, are now very rare.
| Major theories | Concepts | | Astrophysics | Cosmology, Gravitation physics, High-energy astrophysics, Planetary astrophysics, Plasma physics, Space physics, Stellar astrophysics | Big Bang, Lambda-CDM model, Cosmic inflation, General relativity, Law of universal gravitation | Black hole, Cosmic background radiation, Cosmic string, Cosmos, Dark energy, Dark matter, Galaxy, Gravity, Gravitational radiation, Gravitational singularity, Planet, Solar system, Star, Supernova, Universe |
| Atomic, molecular, and optical physics | Atomic physics, Molecular physics, Atomic and Molecular astrophysics, Chemical physics, Optics, Photonics | Quantum optics, Quantum chemistry, Quantum information science | Atom, Molecule, Diffraction, Electromagnetic radiation, Laser, Polarization, Spectral line, Casimir effect |
| Particle physics | Accelerator physics, Nuclear physics, Nuclear astrophysics, Particle astrophysics, Particle physics phenomenology | Standard Model, Quantum field theory, Quantum chromodynamics, Electroweak theory, Effective field theory, Lattice field theory, Lattice gauge theory, Gauge theory, Supersymmetry, Grand unification theory, Superstring theory, M-theory | Fundamental force (gravitational, electromagnetic, weak, strong), Elementary particle, Spin, Antimatter, Spontaneous symmetry breaking, Brane, String, Quantum gravity, Theory of everything, Vacuum energy |
| Condensed matter physics | Solid state physics, High pressure physics, Low-temperature physics, Nanoscale and Mesoscopic physics, Polymer physics | BCS theory, Bloch wave, Fermi gas, Fermi liquid, Many-body theory | Phases (gas, liquid, solid, Bose-Einstein condensate, superconductor, superfluid), Electrical conduction, Magnetism, Self-organization, Spin, Spontaneous symmetry breaking |
The culture of physics research differs from the other sciences in the separation of
theory and
experiment. Since the
20th century, most individual physicists have specialized in either
theoretical physics or
experimental physics. The great
Italian physicist
Enrico Fermi (
1901"
1954), who made fundamental contributions to both theory and experimentation in
nuclear physics, was a notable exception. In contrast, almost all the successful theorists in
biology and
chemistry (e.g. American
quantum chemist and
biochemist Linus Pauling) have also been experimentalists, though this is changing as of late.
Roughly speaking, theorists seek to develop through
abstractions and
mathematical models theories that can both describe and interpret existing experimental results and successfully predict future results, while experimentalists devise and perform experiments to explore new phenomena and test theoretical predictions. Although theory and experiment are developed separately, they are strongly dependent on each other. However, theoretical research in physics may further be considered to draw from
mathematical physics and
computational physics in addition to experimentation. Progress in physics frequently comes about when experimentalists make a discovery that existing theories cannot account for, necessitating the formulation of new theories. Likewise, ideas arising from theory often inspire new experiments. In the absence of experiment, theoretical research can go in the wrong direction; this is one of the criticisms that has been leveled against
M-theory, a popular theory in high-energy physics for which no practical experimental test has ever been devised.
Fringe theories
*
Cold fusion*
Dynamic theory of gravity *
Luminiferous aether*
Steady state theoryPhenomenology
Phenomenology is intermediate between experiment and theory. It is more abstract and includes more logical steps than experiment, but is more directly tied to experiment than theory. The boundaries between theory and phenomenology, and between phenomenology and experiment, are somewhat fuzzy and to some extent depend on the understanding and intuition of the
scientist describing these. An example is Einstein's
1905 paper on the
photoelectric effect,
"On a Heuristic Viewpoint Concerning the Production and Transformation of Light".
Applied physics is physics that is intended for a particular technological or practical use, as for example in
engineering, as opposed to
basic research. This approach is similar to that of
applied mathematics. Applied physics is rooted in the fundamental truths and basic concepts of the physical sciences but is concerned with the utilization of scientific principles in practical devices and systems, and in the application of physics in other areas of science. "Applied" is distinguished from "pure" by a subtle combination of factors such as the motivation and attitude of researchers and the nature of the relationship to the technology or science that may be affected by the work. [
1]
| Branches of Applied Physics | | Acoustics, Agrophysics, Biophysics, Chemical Physics, Communication Physics, Econophysics, Engineering physics, Fluid dynamics, Geophysics, Medical physics, Nanotechnology, Optoelectronics, Photovoltaics, Physical chemistry, Physics of computation, Quantum chemistry, Quantum information science, Vehicle dynamics |
Since antiquity, people have tried to understand the behavior of
matter: why unsupported objects drop to the ground, why different
materials have different properties, and so forth. Also a mystery was the character of the
Universe, such as the form of the
Earth and the behavior of celestial objects such as the
Sun and the
Moon. Several theories were proposed, most of which were wrong. These theories were largely couched in
philosophical terms, and never verified by systematic experimental testing as is popular today. The works of
Ptolemy and
Aristotle however, were also not always found to match everyday observations. There were exceptions and there are
anachronisms: for example,
Indian philosophers and
astronomers gave many correct descriptions in
atomism and
astronomy, and the
Greek thinker
Archimedes derived many correct quantitative descriptions of
mechanics and
hydrostatics.
The willingness to question previously held truths and search for new answers eventually resulted in a period of major scientific advancements, now known as the
Scientific Revolution of the late
17th century. The precursors to the scientific revolution can be traced back to the important developments made in
India and
Persia, including the
elliptical model of the planets based on the
heliocentric solar system of
gravitation developed by
Indian mathematician-astronomer
Aryabhata; the basic ideas of
atomic theory developed by
Hindu and
Jaina philosophers; the theory of light being equivalent to energy particles developed by the Indian
Buddhist scholars
Dignāga and
Dharmakirti; the optical theory of
light developed by
Persian scientist Alhazen; the
Astrolabe invented by the Persian
Mohammad al-Fazari; and the significant flaws in the
Ptolemaic system pointed out by Persian scientist
Nasir al-Din al-Tusi.
As the influence of the
Islamic
Caliphate expanded to Europe, the works of Aristotle preserved by the
Arabs, and the works of the Indians and Persians, became known in Europe by the
12th and
13th centuries. This eventually lead to the scientific revolution which culminated with the publication of the
Philosophiae Naturalis Principia Mathematica in
1687 by the mathematician, physicist, alchemist and inventor Sir
Isaac Newton (
1643-
1727).
The Scientific Revolution is held by most historians (e.g., Howard Margolis) to have begun in
1543, when the first printed copy of
Nicolaus Copernicus's
De Revolutionibus (most of which had been written years prior but whose publication had been delayed) was brought to the influential Polish astronomer from
Nuremberg.
Further significant advances were made over the following century by
Galileo Galilei,
Christiaan Huygens,
Johannes Kepler, and
Blaise Pascal. During the early
17th century,
Galileo pioneered the use of experimentation to validate physical theories, which is the key idea in modern
scientific method. Galileo formulated and successfully tested several results in
dynamics, in particular the Law of
Inertia. In
1687,
Newton published the
Principia, detailing two comprehensive and successful physical theories:
Newton's laws of motion, from which arise
classical mechanics; and
Newton's Law of Gravitation, which describes the
fundamental force of
gravity. Both theories agreed well with experiment. The Principia also included several theories in
fluid dynamics. Classical mechanics was re-formulated and extended by
Leonhard Euler, French mathematician
Joseph-Louis Comte de Lagrange, Irish mathematical physicist
William Rowan Hamilton, and others, who produced new results in mathematical physics. The law of universal gravitation initiated the field of
astrophysics, which describes
astronomical phenomena using physical theories.
After Newton defined
classical mechanics, the next great field of inquiry within physics was the nature of
electricity. Observations in the
17th and
18th century by scientists such as
Robert Boyle,
Stephen Gray, and
Benjamin Franklin created a foundation for later work. These observations also established our basic understanding of electrical charge and
current.
In
1821, the English physicist and chemist
Michael Faraday integrated the study of
magnetism with the study of electricity. This was done by demonstrating that a moving
magnet induced an
electric current in a
conductor. Faraday also formulated a physical conception of
electromagnetic fields.
James Clerk Maxwell built upon this conception, in
1864, with an interlinked set of 20 equations that explained the interactions between
electric and
magnetic fields. These 20 equations were later reduced, using
vector calculus, to a set of
four equations by
Oliver Heaviside.
In addition to other electromagnetic phenomena, Maxwell's equations also can be used to describe
light. Confirmation of this observation was made with the
1888 discovery of
radio by
Heinrich Hertz and in
1895 when
Wilhelm Roentgen detected
X rays. The ability to describe light in electromagnetic terms helped serve as a springboard for
Albert Einstein's publication of the theory of
special relativity in 1905. This theory combined classical mechanics with Maxwell's equations. The theory of
special relativity unifies space and time into a single entity,
spacetime. Relativity prescribes a different transformation between
reference frames than classical mechanics; this necessitated the development of relativistic mechanics as a replacement for classical mechanics. In the regime of low (relative) velocities, the two theories agree. Einstein built further on the special theory by including gravity into his calculations, and published his theory of
general relativity in
1915.
One part of the theory of general relativity is
Einstein's field equation. This describes how the
stress-energy tensor creates curvature of
spacetime and forms the basis of general relativity. Further work on Einstein's field equation produced results which predicted the
Big Bang,
black holes, and the
expanding universe. Einstein believed in a static universe and tried (and failed) to fix his equation to allow for this. However, by
1929 Edwin Hubble's astronomical observations suggested that the universe is expanding.
From the late
17th century onwards,
thermodynamics was developed by physicist and chemist
Boyle,
Young, and many others. In
1733,
Bernoulli used statistical arguments with classical mechanics to derive thermodynamic results, initiating the field of
statistical mechanics. In
1798,
Thompson demonstrated the conversion of mechanical work into heat, and in
1847 Joule stated the law of conservation of
energy, in the form of heat as well as mechanical energy.
Ludwig Boltzmann, in the 19th century, is responsible for the modern form of statistical mechanics.
In
1895,
Röntgen discovered
X-rays, which turned out to be high-frequency electromagnetic radiation.
Radioactivity was discovered in
1896 by
Henri Becquerel, and further studied by
Marie Curie,
Pierre Curie, and others. This initiated the field of
nuclear physics.
In
1897,
Joseph J. Thomson discovered the
electron, the elementary particle which carries electrical current in
circuits. In
1904, he proposed the first model of the
atom, known as the
plum pudding model. (The existence of the atom had been proposed in
1808 by
John Dalton.)
These discoveries revealed that the assumption of many physicists that atoms were the basic unit of
matter was flawed, and prompted further study into the structure of
atoms.
In
1911,
Ernest Rutherford deduced from
scattering experiments the existence of a compact atomic nucleus, with positively charged constituents dubbed
protons.
Neutrons, the neutral nuclear constituents, were discovered in
1932 by
Chadwick. The equivalence of mass and energy (Einstein, 1905) was spectacularly demonstrated during
World War II, as research was conducted by each side into
nuclear physics, for the purpose of creating a
nuclear bomb. The German effort, led by Heisenberg, did not succeed, but the Allied
Manhattan Project reached its goal. In America, a team led by
Fermi achieved the first man-made
nuclear chain reaction in
1942, and in
1945 the world's first
nuclear explosive was detonated at
Trinity site, near
Alamogordo,
New Mexico.
In
1900,
Max Planck published his explanation of
blackbody radiation. This equation assumed that radiators are
quantized in nature, which proved to be the opening argument in the edifice that would become
quantum mechanics.Beginning in
1900,
Planck, Einstein,
Niels Bohr, and others developed
quantum theories to explain various anomalous experimental results by introducing discrete energy levels. In
1925,
Heisenberg and
1926,
Schrödinger and
Paul Dirac formulated
quantum mechanics, which explained the preceding heuristic quantum theories. In quantum mechanics, the outcomes of physical measurements are inherently
probabilistic; the theory describes the calculation of these probabilities. It successfully describes the behavior of matter at small distance scales. During the
1920s Erwin Schrödinger,
Werner Heisenberg, and
Max Born were able to formulate a consistent picture of the chemical behavior of matter, a complete theory of the electronic structure of the atom, as a byproduct of the quantum theory.
Quantum field theory was formulated in order to extend quantum mechanics to be consistent with special relativity. It was devised in the late
1940s with work by
Richard Feynman,
Julian Schwinger,
Sin-Itiro Tomonaga, and
Freeman Dyson. They formulated the theory of
quantum electrodynamics, which describes the electromagnetic interaction, and successfully explained the
Lamb shift. Quantum field theory provided the framework for modern
particle physics, which studies
fundamental forces and elementary particles.
Chen Ning Yang and
Tsung-Dao Lee, in the
1950s, discovered an unexpected
asymmetry in the decay of a
subatomic particle. In
1954, Yang and
Robert Mills then developed a class of
gauge theories which provided the framework for understanding the nuclear forces. The theory for the
strong nuclear force was first proposed by
Murray Gell-Mann. The
electroweak force, the unification of the
weak nuclear force with electromagnetism, was proposed by
Sheldon Lee Glashow,
Abdus Salam and
Steven Weinberg and confirmed in
1964 by
James Watson Cronin and
Val Fitch. This led to the so-called
Standard Model of particle physics in the
1970s, which successfully describes all the elementary particles observed to date.
Quantum mechanics also provided the theoretical tools for
condensed matter physics, whose largest branch is
solid state physics. It studies the physical behavior of solids and liquids, including phenomena such as
crystal structures,
semiconductivity, and
superconductivity. The pioneers of condensed matter physics include
Felix Bloch, who created a quantum mechanical description of the behavior of electrons in crystal structures in
1928. The transistor was developed by physicists
John Bardeen,
Walter Houser Brattain and
William Bradford Shockley in
1947 at
Bell Telephone Laboratories.
The two themes of the
20th century, general relativity and quantum mechanics, appear inconsistent with each other. General relativity describes the
universe on the scale of
planets and
solar systems while quantum mechanics operates on sub-atomic scales. This challenge is being attacked by
string theory, which treats
spacetime as composed, not of points, but of one-dimensional objects,
strings. Strings have properties like a common string (e.g.,
tension and
vibration). The theories yield promising, but not yet testable results. The search for experimental verification of string theory is in progress.
The United Nations declared the year
2005, the centenary of Einstein's
annus mirabilis, as the
World Year of Physics.
Research in physics is progressing constantly on a large number of fronts, and is likely to do so for the foreseeable future.
In condensed matter physics, the biggest unsolved theoretical problem is the explanation for
high-temperature superconductivity. Strong efforts, largely experimental, are being put into making workable
spintronics and
quantum computers.
In particle physics, the first pieces of experimental evidence for physics beyond the
Standard Model have begun to appear. Foremost amongst these are indications that
neutrinos have non-zero
mass. These experimental results appear to have solved the long-standing
solar neutrino problem in solar physics. The physics of massive neutrinos is currently an area of active theoretical and experimental research. In the next several years,
particle accelerators will begin probing energy scales in the
TeV range, in which experimentalists are hoping to find evidence for the
Higgs boson and
supersymmetric particles.
Theoretical attempts to unify
quantum mechanics and
general relativity into a single theory of
quantum gravity, a program ongoing for over half a century, have not yet borne fruit. The current leading candidates are
M-theory,
superstring theory and
loop quantum gravity.
Many
astronomical and
cosmological phenomena have yet to be satisfactorily explained, including the existence of
ultra-high energy cosmic rays, the
baryon asymmetry, the
acceleration of the universe and the
anomalous rotation rates of galaxies.
Although much progress has been made in high-energy,
quantum, and astronomical physics, many everyday phenomena, involving
complexity,
chaos, or
turbulence are still poorly understood. Complex problems that seem like they could be solved by a clever application of dynamics and mechanics, such as the formation of sandpiles, nodes in trickling
water, the shape of water
droplets, mechanisms of
surface tension catastrophes, or self-sorting in shaken heterogeneous collections are unsolved. These complex phenomena have received growing attention since the 1970s for several reasons, not least of which has been the availability of modern
mathematical methods and
computers which enabled
complex systems to be modeled in new ways. The
interdisciplinary relevance of complex physics has also increased, as exemplified by the study of
turbulence in
aerodynamics or the
observation of
pattern formation in
biological systems. In 1932,
Horace Lamb correctly prophesied:
I am an old man now, and when I die and go to heaven there are two matters on which I hope for enlightenment. One is quantum electrodynamics, and the other is the turbulent motion of fluids. And about the former I am rather optimistic.
*
E = mc²*
Classical physics*
Glossary of classical physics*
List of basic physics topics*
List of physics topics*
Unsolved problems in physics*
Philosophy of physics*
Physics (Aristotle) - an early book on physics, which attempted to analyze and define motion from a philosophical point of view
*
Perfection in physics and chemistry*
Mathematics*
Astronomy*
Chemistry*
Engineering* Alpher, Herman, and Gamow.
Nature 162,774 (1948).
Wilson's 1978 Nobel lecture
*
C.S. Wu's contribution to the overthrow of the conservation of parity * Yang, Mills
1954 Physical Review 95, 631; Yang, Mills 1954
Physical Review 96, 191.
Popular Reading
*
University Level Textbooks
Introductory
*
Undergraduate
*
Graduate
*
History
*
*
Contemporary Physics;General
* Aristotle's
Physics, trans. by R. P. Hardie and R. K. Gaye *
Physics and Math Textbooks Numerous online textbooks on Physics and Mathematics
*
Usenet Physics FAQ. A
FAQ compiled by sci.physics and other physics newsgroups.
*
Physics.org - Web portal run by the
Institute of Physics.
*
World of Physics. An online encyclopedic dictionary of physics.
*
Website of the Nobel Prize in Physics.
*
The Physics Network Official Physics Network
*
Physics Today - Your daily physics news and research source
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The Skeptic's Guide to Physics*
PlanetPhysics Online Physics
*
Physics 2005: Website of the
World Year of Physics 2005*
Physicsweb.org*
Physics community The Physics Community accepts contributions from those knowledgeable in physics
*
Contemporary Physics;Organizations
*
AIP.org Website of the
American Institute of Physics*
IOP.org Website of the
Institute of Physics*
APS.org Website of the
American Physical Society*
SPS National Website of the
Society of Physics Students*
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