The world's top physics 1 websites

<h1>Physics</h1><strong>Physics</strong> (from <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/greek_language" title="Greek language">Greek</A> from &#966;&#965;&#963;&#953;&#954;&#972;&#962; (<em>physikos</em>): <em>natural</em>, from &#966;&#973;&#963;&#953;&#962; (<em>physis</em>): <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/nature" title="Nature">Nature</A>) is the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/science_1" title="Science">science</A> of Nature (or <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/natural_science" title="Natural science">natural science</A>) in the broadest sense. <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/list_of_physicists" title="List of physicists">Physicists</A> study the behaviour and interactions of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/matter" title="Matter">matter</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/force" title="Force">force</A>. The <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/law_of_physics" title="Law of physics">laws of physics</A> are generally expressed as <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/mathematics" title="Mathematics">mathematical</A> relations.<p>
Physics is very closely related to the other <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/natural_science" title="Natural science">natural sciences</A>, particularly <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/chemistry" title="Chemistry">chemistry</A>, the science of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/molecule" title="Molecule">molecules</A> and the chemical compounds that they form in bulk.  Chemistry draws on many fields of physics, particularly <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_mechanics_1" title="Quantum mechanics">quantum mechanics</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/thermodynamics" title="Thermodynamics">thermodynamics</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">electromagnetism</A>. However, chemical phenomena are sufficiently varied and complex that chemistry is usually regarded as a separate discipline. Nevertheless, it is widely accepted among chemists and physicists that the laws of physics describe at the most fundamental level all chemical interactions. <p>
In fact, many physicists take the position that physics is the only fundamental science. Their argument runs as follows: all sciences--<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/biology" title="Biology">biology</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/chemistry" title="Chemistry">chemistry</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/geology" title="Geology">geology</A>, etc.--are concerned with <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/matter" title="Matter">matter</A>; all matter is composed of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/atom" title="Atom">atoms</A>; physics describes the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/dynamics" title="Dynamics">dynamics</A> and internal configurations of atoms. Extension of this physico-centric view can result in profound philosophical consequences. For example, if one accepts that the human <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/brain" title="Brain">brain</A> controls all human behavior, and if one accepts that the brain is composed entirely of atoms whose behavior is completely described by laws of physics, then one may reasonably question whether a person has the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/free_will" title="Free will">free will</A> to control his behavior. Nevertheless it is not the task of physics to answer philosophical questions.<p>
A common goal of theoretical physicists is to reduce the description of the physical world to a minimal set of laws governing a finite set of fundamental constituent elements in the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/universe" title="Universe">universe</A>. That the physical world can necessarily be completely reduced in such a way is unclear; one could conceive of a world comprised of an infinite variety of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/particle_physics" title="Particle physics">particles</A> behaving in accordance with an infinite number of laws, or perhaps behaving entirely randomly on occasion. However, thanks to experimental physicists, <strong>physics</strong> have been remarkably successful to date at this reduction process, and the reduction trend is evident in the names of some of the proposed theories listed below.<p>
Physics, like other sciences, is often subdivided into categories: <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/theoretical_physics" title="Theoretical physics">theoretical physics</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/experimental_physics" title="Experimental physics">experimental physics</A> or fundamental research and applied physics. Theoretical physicists seek new fundamental knowledge about the universe, using the observations of experimental physicists. Experimental physicists perform experiments designed to be able to decide which theory is true. Experimental physics often finds completely new phenomena with no existing theory, e.g. <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">electromagnetism</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/radioactivity" title="Radioactivity">radioactivity</A> were discovered this way. Fundamental research quests for the basic structure of nature while applied physicists apply existing knowledge to analyze complex systems in order to use them in practical life and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/economy" title="Economy">economy</A>. Both fundamental research and applied research has theoretical and experimental aspects. As an example, a particularly fertile area of applied physics is <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/condensed_matter_physics" title="Condensed matter physics"> solid-state physics</A>, in which researchers use the more fundamental laws of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_mechanics_1" title="Quantum mechanics">quantum mechanics</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">electromagnetism</A> to analyze the behavior of atoms that comprise a <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/solid" title="Solid">solid</A>.<p>
Below is an overview of the major subfields and concepts in physics, followed by a brief outline of the history of physics and its subfields. A more comprehensive <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/list_of_physics_topics" title="List of physics topics">list of physics topics</A> is also available.<p>
<A NAME=""><H2>Overview of physics</H2><p>
<blockquote>
<A NAME=""><H3>Theories</H3>
<em>Main article</em>: <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/theoretical_physics" title="Theoretical physics">Theories of Physics</A>
<blockquote><p>
<A NAME=""><H4>Central theories</H4>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/classical_mechanics_1" title="Classical mechanics">Classical mechanics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/thermodynamics" title="Thermodynamics">Thermodynamics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/statistical_mechanics_1" title="Statistical mechanics">Statistical mechanics</A> --  <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">Electromagnetism</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/special_relativity" title="Special relativity">Special relativity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/general_relativity" title="General relativity">General relativity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_mechanics_1" title="Quantum mechanics">Quantum mechanics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_field_theory" title="Quantum field theory">Quantum field theory</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/standard_model" title="Standard Model">Standard Model</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fluid_dynamics" title="Fluid dynamics">Fluid dynamics</A><p>
<A NAME=""><H4>Proposed theories</H4>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/theory_of_everything" title="Theory of everything">Theory of everything</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/grand_unification_theory" title="Grand unification theory">Grand unification theory</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/m_theory" title="M-theory">M-theory</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/loop_quantum_gravity" title="Loop quantum gravity">Loop quantum gravity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/emergence" title="Emergence">Emergence</A>
-- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/process_physics" title="Process Physics">Process Physics</A><p>
<A NAME=""><H4>Fringe theories</H4>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/cold_fusion" title="Cold fusion">Cold fusion</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/dynamic_theory_of_gravity" title="Dynamic theory of gravity">Dynamic theory of gravity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/luminiferous_aether" title="Luminiferous aether">Luminiferous aether</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/wilhelm_reich" title="Wilhelm Reich">Orgone energy</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/reciprocal_system_of_theory" title="Reciprocal System of Theory">Reciprocal System of Theory</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/steady_state_theory" title="Steady state theory">Steady state theory</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/time_cube" title="Time Cube">Time Cube</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/unified_field_theory" title="Unified field theory">Unified field theory</A> -- Variable speed of light <p>
</blockquote><p>
<A NAME=""><H3>Concepts</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/matter" title="Matter">Matter</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/antimatter" title="Antimatter">Antimatter</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/elementary_particle" title="Elementary particle">Elementary particle</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/boson" title="Boson">Boson</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fermion" title="Fermion">Fermion</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/symmetry" title="Symmetry">Symmetry</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/motion" title="Motion">Motion</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/conservation_law" title="Conservation law">Conservation law</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/mass" title="Mass">Mass</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/energy" title="Energy">Energy</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/momentum" title="Momentum">Momentum</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/angular_momentum" title="Angular momentum">Angular momentum</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/spin__physics_" title="Spin (physics)">Spin</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/time" title="Time">Time</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/space" title="Space">Space</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/dimension" title="Dimension">Dimension</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/spacetime" title="Spacetime">Spacetime</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/length" title="Length">Length</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/velocity" title="Velocity">Velocity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/force" title="Force">Force</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/torque" title="Torque">Torque</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/wave" title="Wave">Wave</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/wavefunction" title="Wavefunction">Wavefunction</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_entanglement" title="Quantum entanglement">Quantum entanglement</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/harmonic_oscillator" title="Harmonic oscillator">Harmonic oscillator</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/magnetism" title="Magnetism">Magnetism</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electricity" title="Electricity">Electricity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetic_radiation" title="Electromagnetic radiation">Electromagnetic radiation</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/temperature" title="Temperature">Temperature</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/entropy" title="Entropy">Entropy</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/physical_information" title="Physical information">Physical information</A> --
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/vacuum_energy" title="Vacuum energy">Vacuum energy</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/zero_point_energy" title="Zero-point energy">Zero-point energy</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/phase_transition" title="Phase transition">Phase transitions</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/critical_phenomena" title="Critical phenomena">Critical phenomena</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/self_organization" title="Self-organization">Self-organization</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/spontaneous_symmetry_breaking" title="Spontaneous symmetry breaking">Spontaneous symmetry breaking</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/superconductivity" title="Superconductivity">Superconductivity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/superfluid" title="Superfluid">Superfluidity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quantum_phase_transitions" title="Quantum phase transitions">Quantum phase transitions</A><p>
<A NAME=""><H3><A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fundamental_force" title="Fundamental force">Fundamental forces</A></H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/gravity" title="Gravity">Gravitational</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">Electromagnetic</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/weak_nuclear_force" title="Weak nuclear force">Weak</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/strong_interaction" title="Strong interaction">Strong</A><p>
<A NAME=""><H3>Particles</H3>
<em>Main article</em>: <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/particle_physics" title="Particle physics">Particless</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/atom" title="Atom">Atom</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electron" title="Electron">Electron</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/gluon" title="Gluon">Gluon</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/graviton" title="Graviton">Graviton</A>  --  <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/neutrino" title="Neutrino">Neutrino</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/neutron" title="Neutron">Neutron</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/quark" title="Quark">Quark</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/photino" title="Photino">Photino</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/photon" title="Photon">Photon</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/proton" title="Proton">Proton</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/w_and_z_bosons" title="W and Z bosons">W and Z bosons</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/particle_radiation" title="Particle radiation">Particle radiation</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/phonon" title="Phonon">Phonon</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/roton" title="Roton">Roton</A><p>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/boson" title="Boson">Bosons</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fermion" title="Fermion">Fermions</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/supersymmetry" title="Supersymmetry">Supersymmetry</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/higgs_boson" title="Higgs boson">Higgs boson</A><p>
<A NAME=""><H3>Subfields of physics</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/accelerator_physics_1" title="Accelerator physics">Accelerator physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/acoustics" title="Acoustics">Acoustics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/astrophysics" title="Astrophysics">Astrophysics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/atomic__molecular__and_optical_physics" title="Atomic, molecular, and optical physics">Atomic, Molecular, and Optical physics</A> --  <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/computational_physics" title="Computational physics">Computational physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/condensed_matter_physics" title="Condensed matter physics">Condensed matter physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/cosmology" title="Cosmology">Cosmology</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/cryogenics" title="Cryogenics">Cryogenics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fluid_dynamics" title="Fluid dynamics">Fluid dynamics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/polymer_physics" title="Polymer physics">Polymer physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/optics" title="Optics">Optics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/materials_physics" title="Materials physics">Materials physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/nuclear_physics" title="Nuclear physics">Nuclear physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/plasma_physics" title="Plasma physics">Plasma physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/particle_physics" title="Particle physics">Particle physics</A> (or High Energy Physics) -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/vehicle_dynamics" title="Vehicle dynamics">Vehicle dynamics</A><p>
<A NAME=""><H3>Methods</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/scientific_method_1" title="Scientific method">Scientific method</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/physical_quantity" title="Physical quantity">Physical quantity</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/measurement" title="Measurement">Measurement</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/measuring_instrument" title="Measuring instrument">Measuring instruments</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/dimensional_analysis" title="Dimensional analysis">Dimensional analysis</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/statistics" title="Statistics">Statistics</A>--<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/scaling" title="Scaling">Scaling</A><p>
<A NAME=""><H3>Tables</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/list_of_laws_in_science" title="List of laws in science">List of physical laws</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/physical_constant" title="Physical constant">Physical constants</A> -- SI base units -- SI derived units -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/si_prefix" title="SI prefix">SI prefixes</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/conversion_of_units" title="Conversion of units">Unit conversions</A><p>
<A NAME=""><H3>History</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/history_of_physics" title="History of physics">History of Physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/list_of_physicists" title="List of physicists">Famous Physicists</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/nobel_prize_in_physics_1" title="Nobel Prize in Physics">Nobel Prize in physics</A><p>
<A NAME=""><H3>Related Fields</H3>
<A HREF="http://allwebhunt.com/wiki-article-tab.cfm/astronomy" title="Astronomy">Astronomy</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/biophysics" title="Biophysics">Biophysics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/cycles" title="Cycles">Cycles</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electronics" title="Electronics">Electronics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/engineering_1" title="Engineering">Engineering</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/geophysics" title="Geophysics">Geophysics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/materials_science_1" title="Materials science">Materials science</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/mathematical_physics" title="Mathematical physics">Mathematical physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/medical_physics" title="Medical physics">Medical physics</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/physical_chemistry" title="Physical chemistry">Physical chemistry</A> -- <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/physics_of_computation" title="Physics of computation">Physics of computation</A>
</blockquote><p>
<A NAME=""><H2>A brief history of physics</H2>
<em>Note: The following is a cursory overview of the development of physics. For a more detailed history, please refer to the main article on this subject, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/history_of_physics" title="History of physics">History of physics</A>.</em><p>
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 <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/universe" title="Universe">universe</A>, such as the form of the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/earth_1" title="Earth">Earth</A> and the behavior of celestial objects such as the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/sun" title="Sun">Sun</A> and the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/moon" title="Moon">Moon</A>. Several theories were proposed, most of them were wrong. These theories were largely couched in <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/philosophy_1" title="Philosophy">philosophical</A> terms, and never verified by systematic experimental testing. There were exceptions and there are anachronisms: for example, the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/history_of_greece" title="History of Greece">Greek</A> thinker <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/archimedes" title="Archimedes">Archimedes</A> derived many correct quantitative descriptions of mechanics and hydrostatics.<p>
During the early <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/17th_century" title="17th century">17th century</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/galileo_galilei" title="Galileo Galilei">Galileo</A> pioneered the use of experiment to validate physical theories, which is the key idea in the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/scientific_method_1" title="Scientific method">scientific method</A>. Galileo formulated and successfully tested several results in <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/dynamics__mechanics_" title="Dynamics (mechanics)">dynamics</A>, in particular the Law of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/inertia" title="Inertia">Inertia</A>. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1687" title="1687">1687</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/isaac_newton" title="Isaac Newton">Newton</A> published the <em><A HREF="http://allwebhunt.com/wiki-article-tab.cfm/philosophiae_naturalis_principia_mathematica" title="Philosophiae Naturalis Principia Mathematica">Principia Mathematica</A></em>, detailing two comprehensive and successful physical theories:  <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/newton_s_laws_of_motion_1" title="Newton's laws of motion">Newton's laws of motion</A>, from which arise <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/classical_mechanics_1" title="Classical mechanics">classical mechanics</A>; and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/gravity" title="Gravity">Newton's Law of Gravitation</A>, which describes the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/fundamental_force" title="Fundamental force">fundamental force</A> of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/gravity" title="Gravity">gravity</A>. Both theories agreed well with experiment. Classical mechanics would be exhaustively extended by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/joseph_louis_lagrange" title="Joseph Louis Lagrange">Lagrange</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/william_rowan_hamilton" title="William Rowan Hamilton">Hamilton</A>, and others, who produced new formulations, principles, and results. The Law of Gravitation initiated the field of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/astrophysics" title="Astrophysics">astrophysics</A>, which describes <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/astronomy" title="Astronomy">astronomical</A> phenomena using physical theories.<p>
From the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/18th_century" title="18th century">18th century</A> onwards, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/thermodynamics" title="Thermodynamics">thermodynamics</A> was developed by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/robert_boyle" title="Robert Boyle">Boyle</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/thomas_young" title="Thomas Young">Young</A>, and many others. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1733" title="1733">1733</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/daniel_bernoulli" title="Daniel Bernoulli">Bernoulli</A> used statistical arguments with classical mechanics to derive thermodynamic results, initiating the field of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/statistical_mechanics_1" title="Statistical mechanics">statistical mechanics</A>. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1798" title="1798">1798</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/benjamin_thompson" title="Benjamin Thompson">Thompson</A> demonstrated the conversion of mechanical work into heat, and in <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1847" title="1847">1847</A> <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/james_prescott_joule" title="James Prescott Joule">Joule</A> stated the law of conservation of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/energy" title="Energy">energy</A>, in the form of heat as well as mechanical energy.<p>
The behavior of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electricity" title="Electricity">electricity</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/magnetism" title="Magnetism">magnetism</A> was studied by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/michael_faraday" title="Michael Faraday">Faraday</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/georg_ohm" title="Georg Ohm">Ohm</A>, and others. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1855" title="1855">1855</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/james_clerk_maxwell" title="James Clerk Maxwell">Maxwell</A> unified the two phenomena into a single theory of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetism" title="Electromagnetism">electromagnetism</A>, described by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/maxwell_s_equations" title="Maxwell's equations">Maxwell's equations</A>. A prediction of this theory was that <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/light" title="Light">light</A> is an <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electromagnetic_radiation" title="Electromagnetic radiation">electromagnetic wave</A>.<p>
In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1895" title="1895">1895</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/wilhelm_roentgen" title="Wilhelm RÃƒï¿½Ã¯ï¿½ï¿½ntgen">Roentgen</A> discovered <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/x_ray" title="X-ray">X-rays</A>, which turned out to be high-frequency electromagnetic radiation. <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/radioactivity" title="Radioactivity">Radioactivity</A> was discovered in <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1896" title="1896">1896</A> by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/henri_becquerel" title="Henri Becquerel">Henri Becquerel</A>, and further studied by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/pierre_curie" title="Pierre Curie">Pierre Curie</A> and <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/marie_curie" title="Marie Curie">Marie Curie</A> and others. This initiated the field of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/nuclear_physics" title="Nuclear physics">nuclear physics</A>.<p>
In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1897" title="1897">1897</A>, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/joseph_john_thomson" title="Joseph John Thomson">Thomson</A> discovered the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/electron" title="Electron">electron</A>, the elementary particle which carries electrical current in circuits. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1904" title="1904">1904</A>, he proposed the first model of the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/atom" title="Atom">atom</A>, known as the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/plum_pudding_model" title="Plum pudding model">plum pudding model</A>. (The existence of the atom had been proposed in <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1808" title="1808">1808</A> by <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/john_dalton" title="John Dalton">Dalton</A>.)<p>
In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1905" title="1905">1905</A>, Einstein formulated the theory of <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/special_relativity" title="Special relativity">special relativity</A>, unifying space and time into a single entity, <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/spacetime" title="Spacetime">spacetime</A>. Relativity prescribes a different transformation between <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/inertial_frame_of_reference" title="Inertial frame of reference">reference frames</A> 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. In <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/1915" title="1915">1915</A>, Einstein extended special relativity to explain gravity with the <A HREF="http://allwebhunt.com/wiki-article-tab.cfm/general_relativity" title="General relativity">general theory of relativity</A>, which replace.