In science, there are a specific number of established scientific laws, or physical laws as they are sometimes called, that are considered absolute and inarguable facts of the physical world. Laws of science may, however, be disproved if new facts or evidence arise to contradict them. A "law" differs from those as hypotheses, theories, postulates, and principles, etc., in that a law is a general statement about nature that is considered proven beyond doubt. Conservative estimates indicate that there are 18 basic physical laws in the universe: ^[1] Part of a scientific laboratory at the University of Cologne. ... A scientific law is a general and reasonably simple principle that is very well supported by evidence such as experimental results and observational data. ... A physical law, scientific law, or a law of nature is a scientific generalization based on empirical observations of physical behavior. ... A hypothesis (= assumption in ancient Greek) is a proposed explanation for a phenomenon. ... In mathematics, theory is used informally to refer to a body of knowledge about mathematics. ... For the algebra software named Axiom, see Axiom computer algebra system. ... A principle (not principal) is something, usually a rule or norm, that is part of the basis for something else. ...

Others, such as Roger Penrose with his 2004 book The Road to Reality – a complete guide to the laws of the universe, argues that there are a large number of established laws of science. Some laws, such as Descartes’ first law of nature, have become obsolete. A rough outline of the basic laws in science is as follows: In quantum physics, the Heisenberg uncertainty principle is a mathematical limit on the accuracy with which it is possible to measure everything there is to know about a physical system. ... Sir Roger Penrose, OM, FRS (born 8 August 1931) is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College. ... The Road to Reality is a book by the British mathematical physicist Roger Penrose, published in 2004. ... A physical law or a law of nature is a scientific generalization based on empirical observations. ... René Descartes René Descartes (IPA: , March 31, 1596 – February 11, 1650), also known as Cartesius, worked as a philosopher and mathematician. ...

Conservation laws

Most significant laws in science are conservation laws: In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves. ...

• Conservation of energy law
• Conservation of momentum law
• Conservation of angular momentum law
• Charge conservation law

These fundamental laws follow from homogeneity of space, time and phase (see Emmy Noether theorem). Conservation of energy states that the total amount of energy in an isolated system remains constant, although it may change forms (for instance, friction turns kinetic energy into thermal energy). ... In classical mechanics, momentum (pl. ... Gyroscope. ... Charge conservation is the principle that electric charge can neither be created nor destroyed. ... Space has been an interest for philosophers and scientists for much of human history. ... A pocket watch, a device used to keep time There are two distinct views on the meaning of time. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Gas laws

Other less significant (non fundamental) laws are the mathematical consequences of the above conservation laws for derivative physical quantities (mathematically defined as force, pressure, temperature, density, force fields, etc): In physics, force is an influence that may cause a body to accelerate. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ... Fig. ... Density, or volumic mass (ISO 31), is a measure of mass per unit volume. ... Originally a term coined by Michael Faraday to provide an intuitive paradigm, but theoretical construct (in the Kuhnian sense), for the behavior of electromagnetic fields, the term force field refers to the lines of force one object (the source object) exerts on another object or a collection of other objects. ...

• Boyle's Law (pressure and volume of ideal gas)
• Charles & Gay-Lussac (gases expand equally with the same change of temperature)
• Ideal Gas Law

Boyles law (sometimes referred to as the Boyle Mariotte law), one of the gas laws, states that the product of the pressure and volume of a fixed quantity of ideal gas, when held at a fixed temperature, is a constant. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ... Volume is how much space a thing has. ... An ideal gas or perfect gas is a hypothetical gas consisting of identical particles of zero volume, with no intermolecular forces. ... The Law of Charles and Gay-Lussac (frequently called simply Charles Law) is one of the gas laws, and relates the volume and temperature of an ideal gas held at a constant pressure. ... Fig. ... Isotherms of an ideal gas The ideal gas law is the equation of state of a hypothetical ideal gas. ...

Einstein's laws

Einstein Albert Einstein ( ) (March 14, 1879 – April 18, 1955) was a German-born theoretical physicist who is widely considered one of the greatest physicists of all time. ...

• Energy of photons - Energy equals Planck's constant multiplied by the frequency of the light.

Special Relativity

• Constancy of the speed of light
• Lorentz transformations - Transformations of Cartesian coordinates between relatively moving reference frames.

  y' = y

  z' = z

• Law of force - Force equals mass times acceleration divided by the square root of one minus the ratio squared of the object's velocity to the speed of light.

• Mass-energy equivalence

  (Energy = mass × speed of light²)

General Relativity

• Energy-momentum (including mass via E=mc²) curves spacetime.

  This is described by the Einstein field equations:

  R_ab is the Ricci tensor, R is the Ricci scalar, g_ab is the metric tensor, T_ab is the stress-energy tensor, and the constant is given in terms of π (pi), c (the speed of light) and G (the gravitational constant).

The word light is defined here as electromagnetic radiation of any wavelength; thus, X-rays, gamma rays, ultraviolet light, microwaves, radio waves, and visible light are all forms of light. ... A commemoration plaque for Max Planck on his discovery of Plancks constant, in front of Humboldt University, Berlin. ... Sine waves of various frequencies; the bottom waves have higher frequencies than those above. ... Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength[1]. The elementary particle that defines light is the photon. ... The special theory of relativity was proposed in 1905 by Albert Einstein in his article On the Electrodynamics of Moving Bodies. Some three centuries earlier, Galileos principle of relativity had stated that all uniform motion was relative, and that there was no absolute and well-defined state of rest... The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. It is the speed of all electromagnetic radiation in a vacuum, not just visible light. ... The Lorentz transformation (LT), named after its discoverer, the Dutch physicist and mathematician Hendrik Antoon Lorentz (1853-1928), forms the basis for the special theory of relativity, which has been introduced to remove contradictions between the theories of electromagnetism and classical mechanics. ... Fig. ... A frame of reference in physics is a set of axes which enable an observer to measure the aspect, position and motion of all points in a system relative to the reference frame. ... In physics, force is an influence that may cause a body to accelerate. ... In physics, force is an influence that may cause a body to accelerate. ... Unsolved problems in physics: What causes anything to have mass? Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... Acceleration is the time rate of change of velocity, and at any point on a velocity-time graph, it is given by the slope of the tangent to that point In physics or physical science, acceleration (symbol: a) is defined as the rate of change (or derivative with respect to... In mathematics, a square root of a number x is a number whose square (the result of multiplying the number by itself) is x. ... One redirects here. ... A ratio is a dimensionless, or unitless, quantity denoting an amount or magnitude of one quantity relative to another. ... In algebra, the square of x is written x2 and is defined as the product of x with itself: x × x. ... The velocity of an object is its total speed in a particular direction. ... Albert Einsteins equation E=mc² is among the best-known equations of all time. ... Unsolved problems in physics: What causes anything to have mass? Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. It is the speed of all electromagnetic radiation in a vacuum, not just visible light. ... General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915/16. ... This article or section is in need of attention from an expert on the subject. ... In differential geometry, the Ricci curvature tensor is (0,2)-valent tensor, obtained as a trace of the full curvature tensor. ... In Riemannian geometry, the scalar curvature (or Ricci scalar) is the simplest way of describing the curvature of a Riemannian manifold. ... In general relativity, the metric tensor (or simply the metric) is the fundamental object of study. ... This article is in need of attention from an expert on the subject. ... This article is about the number. ... The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. It is the speed of all electromagnetic radiation in a vacuum, not just visible light. ... According to the law of universal gravitation, the attractive force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. ...

Newton's laws

Newton Sir Isaac Newton, (4 January 1643 – 31 March 1727) [ OS: 25 December 1642 – 20 March 1727][1] was an English physicist, mathematician, astronomer, alchemist, and natural philosopher, regarded by many as the greatest figure in the history of science. ...

• Newton's laws of motion - Replaced with relativity

  *1. Law of Inertia

  *2. Force equals mass times acceleration.

  *3. F_ab = − F_ba Force of a on b equals the negative force of b on a, or for every action there is an equal and opposite reaction.

• Law of heat conduction
• General law of gravitation - Gravitational force between two objects equals the gravitational constant times the product of the masses divided by the distance between them squared.

  This law is really just the low limit solution of Einstein's field equations and is not accurate with modern high precision gravitational measurements.

Newtons First and Second laws, in Latin, from the original 1687 edition of the Principia Mathematica. ... Two-dimensional analogy of space-time distortion described in General Relativity. ... The principle of inertia is one of the fundamental laws of classical physics which are used to describe the motion of matter and how it is affected by applied forces. ... A negative number is a number that is less than zero, such as −3. ... In physics, the action is an integral quantity that is used to determine the evolution of a physical system between two defined states using the calculus of variations. ... A reaction is the following: In physics, a reaction (physics) is defined by Newtons third law: For every action there is an equal and opposite reaction. The idea that any given force has a pair or opposite force. ... Heat flow along perfectly insulated wire Conduction is the transfer of heat or electric current from one substance to another by direct contact. ... Gravity is a force of attraction that acts between bodies that have mass. ... This article covers the physics of gravitation. ... According to the law of universal gravitation, the attractive force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. ... Unsolved problems in physics: What causes anything to have mass? Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... Distance is a numerical description of how far apart things lie. ... For other topics related to Einstein see Einstein (disambig) Introduction In physics, the Einstein field equation or Einstein equation is a tensor equation in the Einsteins theory of general relativity. ...

Electromagnetic laws

• Coulomb's law - Force between any two charges is equal to the absolute value of the multiple of the charges divided by 4 pi times the vacuum permittivity times the distance squared between the two charges.

• Ohm's Law

• Kirchhoff's circuit laws (current and voltage laws)
• Kirchhoff's law of thermal radiation
• Maxwell's equations (electric and magnetic fields):

Coulombs torsion balance In physics, Coulombs law is an inverse-square law indicating the magnitude and direction of electrostatic force that one stationary, electrically charged object of small dimensions (ideally, a point source) exerts on another. ... In physics, force is an influence that may cause a body to accelerate. ... Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ... In mathematics, the absolute value (or modulus1) of a real number is its numerical value without regard to its sign. ... This article is about the number. ... Permittivity is a physical quantity that describes how an electric field affects and is affected by a dielectric medium and is determined by the ability of a material to polarize in response to an applied electric field, and thereby to cancel, partially, the field inside the material. ... Distance is a numerical description of how far apart things lie. ... Ohms law states that, in an electrical circuit, the current passing through a conductor is directly proportional to the potential difference applied across them provided all physical conditions are kept constant. ... Kirchhoffs circuit laws are a pair of laws that deal with the conservation of charge and energy in electrical circuits, and were first described in 1845 by Gustav Kirchhoff. ... In electricity, current refers to electric current, which is the flow of electric charge. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... Kirchhoffs law in thermodynamics, also called e. ... In electromagnetics, Maxwells equations are a set of four equations, compiled by James Clerk Maxwell, that describe the behavior of both the electric and magnetic fields, as well as their interactions with matter. ... It has been suggested that optical field be merged into this article or section. ... Current (I) flowing through a wire produces a magnetic field () around the wire. ... In physics and mathematical analysis, Gausss law, closely related to Gausss theorem, gives the relation between the electric or gravitational flux flowing out a closed surface and, respectively, the electric charge or mass enclosed in the surface. ... Faradays law of induction (more generally, the law of electromagnetic induction) states that the induced emf (electromotive force) in a closed loop equals the negative of the time rate of change of magnetic flux through the loop. ... In physics, Ampères law is the magnetic equivalent of Gausss law, discovered by André-Marie Ampère. ...

Thermodynamic laws

Thermodynamics Thermodynamics (from the Greek thermos meaning heat and dynamics meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ...

• Zeroth law of thermodynamics

• First law of thermodynamics

• Second law of thermodynamics

• Third law of thermodynamics

• Onsager reciprocal relations - sometimes called the Fourth Law of Thermodynamics

  ;

  .

The zeroth law of thermodynamics may be succintly stated as: If two thermodynamic systems A and B are in thermal equilibrium, and B and C are also in thermal equilibrium, then A and C are in thermal equilibrium. ... The first law of thermodynamics, a generalized expression of the law of the conservation of energy, states: // Description Essentially, the First Law of Thermodynamics declares that energy is conserved for a closed system, with heat and work being the forms of energy transfer. ... The second law of thermodynamics is an expression of the universal law of increasing entropy. ... The third law of thermodynamics (hereinafter Third Law) states that as a system approaches the zero absolute temperature (hereinafter ZAT), all processes cease and the entropy of the system approaches a minimum value. ... In thermodynamics, the Onsager reciprocal relations express the equality of certain relations between flows and forces in thermodynamical systems out of equilibrium, but where a notion of local equilibrium exists. ...

Quantum laws

Quantum Mechanics Fig. ...

• Heisenberg Uncertainty Principle - Uncertainty in position multiplied by uncertainty in momentum is equal to or greater than Dirac's constant divided by 2.

• De Broglie hypothesis - Laid the foundations of particle-wave duality and was the key idea in the Schrödinger equation.

• Schrödinger equation - Describes the time dependence of a quantum mechanical system.

  The Hamiltonian H(t) is a self-adjoint operator acting on the state space, ψ(t) is the instantaneous state vector at time t, i is the unit imaginary number, is Planck's constant divided by 2π

It is thought that the successful integration of Einstein's field equations with the uncertainty principle and Schrödinger equation, something no one has achieved so far with a testable theory, will lead to a theory of quantum gravity, the most basic physical law sought after today. In quantum physics, the Heisenberg uncertainty principle, sometimes called the Heisenberg indeterminacy principle, expresses a limitation on accuracy of (nearly) simultaneous measurement of observables such as the position and the momentum of a particle. ... Uncertainty is a term used in subtly different ways in a number of fields, including philosophy, statistics, economics, finance, insurance, psychology, engineering and science. ... Look up position in Wiktionary, the free dictionary. ... In classical mechanics, momentum (pl. ... Plancks constant, denoted h, is a physical constant that is used to describe the sizes of quanta. ... In physics, the de Broglie hypothesis is the statement that all matter has a wave-like nature (wave-particle duality). ... In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the space- and time-dependence of quantum mechanical systems. ... The quantum Hamiltonian is the physical state of a system, which may be characterized as a ray in an abstract Hilbert space (or, in the case of ensembles, as a trace class operator with trace 1). ... On a finite-dimensional inner product space, a self-adjoint operator is one that is its own adjoint, or, equivalently, one whose matrix is Hermitian, where a Hermitian matrix is one which is equal to its own conjugate transpose. ... Quite literally, quantum state describes the state of a quantum system. ... A commemoration plaque for Max Planck on his discovery of Plancks constant, in front of Humboldt University, Berlin. ... For other topics related to Einstein see Einstein (disambig) Introduction In physics, the Einstein field equation or Einstein equation is a tensor equation in the Einsteins theory of general relativity. ... In quantum physics, the Heisenberg uncertainty principle is a mathematical limit on the accuracy with which it is possible to measure everything there is to know about a physical system. ... In physics, the Schrödinger equation, proposed by the Austrian physicist Erwin Schrödinger in 1925, describes the space- and time-dependence of quantum mechanical systems. ... The word theory has a number of distinct meanings in different fields of knowledge, depending on their methodologies and the context of discussion. ... This article or section does not cite its references or sources. ...

Other laws

• Navier-Stokes equations of fluid dynamics

• Poiseuille's law (voluminal laminar stationary flow of incompressible uniform viscous liquid through a cylindrical tube with the constant circular cross-section)

Radiation laws The Navier-Stokes equations, named after Claude-Louis Navier and George Gabriel Stokes, are a set of equations that describe the motion of fluid substances such as liquids and gases. ... Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... The Poiseuilles law (or the Hagen-Poiseuille law also named after Gotthilf Heinrich Ludwig Hagen (1797-1884) for his experiments in 1839) is the physical law concerning the voluminal laminar stationary flow ΦV of incompressible uniform viscous liquid (so called Newtonian fluid) through a cylindrical tube with the constant... laminar and turbulent water flow over the hull of a submarine In fluid dynamics, laminar flow is a flow regime characterized by high momentum diffusion, low momentum convection, and pressure and velocity independence from time. ... Stationary can mean: Look up stationary in Wiktionary, the free dictionary. ... In fluid dynamics, potential flow, also known as irrotational flow (of incompressible fluids) is steady flow defined by the equations Note that ∇ · v is something different than ∇ v The equations above imply , or Laplaces equation, holds. ... The pitch drop experiment at the University of Queensland. ... Radiation in physics is the process of emitting energy in the form of waves or particles. ...

• Planck's law of black body radiation (spectral density in a radiation of a black-body)
• Wien's law (wavelength of the peak of the emission of a black body) :λ₀T = k_w
• Stefan-Boltzmann law (total radiation from a black body)

• Laws of Kepler (planetary motion)
• Beer-Lambert (light absorption)
• Dulong-Petit law (specific heat capacity at constant volume)

• Buys-Ballot's law (wind travels counterclockwise around low pressure systems in the Northern Hemisphere)

Black body spectrum In physics, Plancks law of black body radiation predicts the spectral intensity of electromagnetic radiation at all wavelengths from a black body at temperature  : where the following table provides the definition and SI units of measure for each symbol: The wavelength is related to the frequency... In applied mathematics and physics, the spectral density is a general concept applied to a signal which may have any physical dimensions or none at all. ... Radiation in physics is the process of emitting energy in the form of waves or particles. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... Wiens displacement law is a law of physics that states that there is an inverse relationship between the wavelength of the peak of the emission of a black body and its temperature. ... The Stefan-Boltzmann law, also known as Stefans law, states that the total energy radiated per unit surface area of a black body in unit time (known variously as the black-body irradiance, energy flux density, radiant flux, or the emissive power), j*, is directly proportional to the fourth... Johannes Keplers primary contributions to astronomy/astrophysics were the three laws of planetary motion. ... ... In optics, the Beer-Lambert law, also known as Beers law or the Lambert-Beer law or the Beer-Lambert-Bouguer law is an empirical relationship that relates the absorption of light to the properties of the material through which the light is travelling. ... The Dulong-Petit law, found in 1819 by Pierre Louis Dulong and Alexis Thérèse Petit, states the classical expression for the specific heat capacity of a crystal due to its lattice vibrations. ... Specific heat capacity, also known simply as specific heat (Symbol: C or c) is the measure of the heat energy required to raise the temperature of a specific quantity of a substance (thus, the name “specific” heat) by certain amount, usually one kelvin. ... C.H.D. Buys Ballot Buys-Ballots law, in meteorology, is the name given to a law which may be expressed as follows: In the Northern Hemisphere, stand with your back to the wind; the low pressure area will be on your left. ... A low, or a low pressure area, is a region of rising atmospheric air. ... The Northern Hemisphere is the half of a planets surface (or celestial sphere) that is north of the equator (the word hemisphere literally means half ball). On the Earth, the Northern Hemisphere contains most of the land and about 88-90% of the human population. ...

References

1. ^ Powell, Michael (2004). Stuff You Should Have Learned at School. Barnes & Noble Books. ISBN 0-7607-6279-1. 

See also

• Scientific laws named after people