List of eponymous laws
Encyclopedia
This list of eponymous laws provides links to articles on laws, adage
s, and other succinct observations or predictions named after a person. In some cases the person named has coined the law – such as Parkinson's law
. In others, the work or publications of the individual have led to the law being so named – as is the case with Moore's law
. There are also laws ascribed to individuals by others, such as Murphy's law
; or given eponym
ous names despite the absence of the named person.
Adage
An adage is a short but memorable saying which holds some important fact of experience that is considered true by many people, or that has gained some credibility through its long use....
s, and other succinct observations or predictions named after a person. In some cases the person named has coined the law – such as Parkinson's law
Parkinson's law
Parkinson's law is the adage first articulated by Cyril Northcote Parkinson as the first sentence of a humorous essay published in The Economist in 1955:...
. In others, the work or publications of the individual have led to the law being so named – as is the case with Moore's law
Moore's Law
Moore's law describes a long-term trend in the history of computing hardware: the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years....
. There are also laws ascribed to individuals by others, such as Murphy's law
Murphy's law
Murphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong". - History :The perceived perversity of the universe has long been a subject of comment, and precursors to the modern version of Murphy's law are not hard to find. Recent significant...
; or given eponym
Eponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
ous names despite the absence of the named person.
A–B
- Aitken's lawScottish Vowel Length RuleThe Scottish vowel length rule, also known as Aitken's law after Professor A.J. Aitken, who formulated it, describes how vowel length in Scots, Scottish English, and to some extent Mid Ulster English, is conditioned by environment.- Phonemes :...
– describes how vowel lengthVowel lengthIn linguistics, vowel length is the perceived duration of a vowel sound. Often the chroneme, or the "longness", acts like a consonant, and may etymologically be one, such as in Australian English. While not distinctive in most dialects of English, vowel length is an important phonemic factor in...
in ScotsScots languageScots is the Germanic language variety spoken in Lowland Scotland and parts of Ulster . It is sometimes called Lowland Scots to distinguish it from Scottish Gaelic, the Celtic language variety spoken in most of the western Highlands and in the Hebrides.Since there are no universally accepted...
and Scottish EnglishScottish EnglishScottish English refers to the varieties of English spoken in Scotland. It may or may not be considered distinct from the Scots language. It is always considered distinct from Scottish Gaelic, a Celtic language....
is conditioned by environment. Named for Professor A. J. Aitken, who formulated it. - Amara's lawRoy AmaraRoy Amara was a researcher, scientist and past president of the Institute for the Future. Born in Boston 1925, he has also worked at Stanford Research Institute....
– "We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run." - Amdahl's lawAmdahl's lawAmdahl's law, also known as Amdahl's argument, is named after computer architect Gene Amdahl, and is used to find the maximum expected improvement to an overall system when only part of the system is improved...
– Used to find out the maximum expected improvement to an overall system when only a part of it is improved. Named after Gene AmdahlGene AmdahlGene Myron Amdahl is a Norwegian-American computer architect and high-tech entrepreneur, chiefly known for his work on mainframe computers at IBM and later his own companies, especially Amdahl Corporation...
(born 1922). - Ampère's lawAmpère's lawIn classical electromagnetism, Ampère's circuital law, discovered by André-Marie Ampère in 1826, relates the integrated magnetic field around a closed loop to the electric current passing through the loop...
– In physics, it relates the circulating magnetic fieldMagnetic fieldA magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
in a closed loop to the electric currentElectric currentElectric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
passing through the loop. Discovered by André-Marie AmpèreAndré-Marie AmpèreAndré-Marie Ampère was a French physicist and mathematician who is generally regarded as one of the main discoverers of electromagnetism. The SI unit of measurement of electric current, the ampere, is named after him....
. - Archie's law – In petrophysics, relates the in-situ electrical conductivity of sedimentary rockSedimentary rockSedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
to its porosity and brineBrineBrine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...
saturationAquiferAn aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
. Named for Gus Archie (1907–1978). - Asimov's three laws of roboticsThree Laws of RoboticsThe Three Laws of Robotics are a set of rules devised by the science fiction author Isaac Asimov and later added to. The rules are introduced in his 1942 short story "Runaround", although they were foreshadowed in a few earlier stories...
– Also called, more simply, the three laws of robotics or just the three laws, a set of rules which the fictional robotRobotA robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control. In practice a robot is usually an electro-mechanical machine that is guided by computer and electronic programming. Robots can be autonomous, semi-autonomous or...
s appearing in the writings of Isaac AsimovIsaac AsimovIsaac Asimov was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000...
(1920–1992) must obey. There were eventually four laws when the Zeroth was added. - Augustine's lawsAugustine's lawsAugustine's laws were a series of tongue in cheek aphorisms put forth by Norman Ralph Augustine, an American aerospace businessman who served as Under Secretary of the Army from 1975 to 1977...
– on air force management. Named for Norman Augustine. - Avogadro's lawAvogadro's lawAvogadro's law is a gas law named after Amedeo Avogadro who, in 1811, hypothesized that two given samples of an ideal gas, at the same temperature, pressure and volume, contain the same number of molecules...
– In chemistryChemistryChemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
and physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, one of the gas lawsGas lawsThe early gas laws were developed at the end of the 18th century, when scientists began to realize that relationships between the pressure, volume and temperature of a sample of gas could be obtained which would hold for all gases...
, relating to the volume and molarity of a gas. - Bayes' theoremBayes' theoremIn probability theory and applications, Bayes' theorem relates the conditional probabilities P and P. It is commonly used in science and engineering. The theorem is named for Thomas Bayes ....
– In probability theoryProbability theoryProbability theory is the branch of mathematics concerned with analysis of random phenomena. The central objects of probability theory are random variables, stochastic processes, and events: mathematical abstractions of non-deterministic events or measured quantities that may either be single...
, shows the relation between one conditional probability and its inverse. - Beer–Lambert law – In opticsOpticsOptics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...
, the empirical relationshipEmpirical relationshipIn science, an empirical relationship is one based solely on observation rather than theory. An empirical relationship requires only confirmatory data irrespective of theoretical basis. Sometimes theoretical explanations for what were initially empirical relationships are found, in which case the...
of the absorptionAbsorption (electromagnetic radiation)In physics, absorption of electromagnetic radiation is the way by which the energy of a photon is taken up by matter, typically the electrons of an atom. Thus, the electromagnetic energy is transformed to other forms of energy for example, to heat. The absorption of light during wave propagation is...
of lightLightLight or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
to the properties of the material through which the light is traveling. Independently discovered (in various forms) by Pierre BouguerPierre BouguerPierre Bouguer was a French mathematician, geophysicist, geodesist, and astronomer. He is also known as "the father of naval architecture"....
in 1729, Johann Heinrich LambertJohann Heinrich LambertJohann Heinrich Lambert was a Swiss mathematician, physicist, philosopher and astronomer.Asteroid 187 Lamberta was named in his honour.-Biography:...
in 1760 and August BeerAugust BeerAugust Beer was a German physicist and mathematician. Beer was born in Trier, where he studied mathematics and natural sciences. He worked for Julius Plücker in Bonn afterwards, where he earned a Ph.D. in 1848 and became a lecturer in 1850. In 1854, Beer published his book Einleitung in die höhere...
in 1852. - Benford's lawBenford's lawBenford's law, also called the first-digit law, states that in lists of numbers from many real-life sources of data, the leading digit is distributed in a specific, non-uniform way...
– In any collection of statistics, a given statistic has roughly a 30% chance of starting with the digit 1. - Biot–Savart law – Describes the magnetic fieldMagnetic fieldA magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
set up by a steady current densityCurrent densityCurrent density is a measure of the density of flow of a conserved charge. Usually the charge is the electric charge, in which case the associated current density is the electric current per unit area of cross section, but the term current density can also be applied to other conserved...
. Named for Jean-Baptiste BiotJean-Baptiste BiotJean-Baptiste Biot was a French physicist, astronomer, and mathematician who established the reality of meteorites, made an early balloon flight, and studied the polarization of light.- Biography :...
and Félix SavartFélix SavartFélix Savart became a professor at Collège de France in 1836 and was the co-originator of the Biot-Savart Law, along with Jean-Baptiste Biot. Together, they worked on the theory of magnetism and electrical currents. Their law was developed about 1820. The Biot-Savart Law relates magnetic fields to...
. - Birch's law – In geophysicsGeophysicsGeophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
, establishes a linear relation of the compressional wave velocity of rocks and minerals of a constant average atomic weight. Named after Francis BirchFrancis Birch (geophysicist)Albert Francis Birch was an American geophysicist best known for his experimental work on the properties of Earth-forming minerals at high pressure and temperature, in 1952 he published a well-known paper in the Journal of Geophysical Research ,where he demonstrated that the mantle is chiefly...
. - Boyle's lawBoyle's lawBoyle's law is one of many gas laws and a special case of the ideal gas law. Boyle's law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system...
– In physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, one of the gas lawsGas lawsThe early gas laws were developed at the end of the 18th century, when scientists began to realize that relationships between the pressure, volume and temperature of a sample of gas could be obtained which would hold for all gases...
, relating the volume and pressure of an ideal gas held at a constant temperatureTemperatureTemperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
. Discovered by and named after Robert BoyleRobert BoyleRobert Boyle FRS was a 17th century natural philosopher, chemist, physicist, and inventor, also noted for his writings in theology. He has been variously described as English, Irish, or Anglo-Irish, his father having come to Ireland from England during the time of the English plantations of...
(1627–1691). - Bradford's lawBradford's lawBradford's law is a pattern first described by Samuel C. Bradford in 1934 that estimates the exponentially diminishing returns of extending a search for references in science journals...
– a pattern described by Samuel C. Bradford in 1934 that estimates the exponentially diminishing returns of extending a library search. - Bremermann's limitBremermann's limitBremermann's Limit, named after Hans-Joachim Bremermann, is the maximum computational speed of a self-contained system in the material universe. It is derived from Einstein's mass-energy equivalency and the Heisenberg uncertainty principle, and is c2/h ≈ 1.36 × 1050 bits per second per...
– Named after Hans-Joachim BremermannHans-Joachim BremermannHans-Joachim Bremermann was a German-American mathematician and biophysicist. He worked on computer science and evolution, introducing new ideas of how mating generates new gene combinations...
, is the maximum computational speed of a self-contained system in the material universe. - Brooks' lawBrooks' lawBrooks's law is a principle in software development which says that "adding manpower to a late software project makes it later". It was coined by Fred Brooks in his 1975 book The Mythical Man-Month. The corollary of Brooks's Law is that there is an incremental person who, when added to a project,...
– "Adding manpower to a late software project makes it later." Named after Fred BrooksFred BrooksFrederick Phillips Brooks, Jr. is a software engineer and computer scientist, best known for managing the development of IBM's System/360 family of computers and the OS/360 software support package, then later writing candidly about the process in his seminal book The Mythical Man-Month...
, author of the well known book on project managementProject managementProject management is the discipline of planning, organizing, securing, and managing resources to achieve specific goals. A project is a temporary endeavor with a defined beginning and end , undertaken to meet unique goals and objectives, typically to bring about beneficial change or added value...
The Mythical Man-MonthThe Mythical Man-MonthThe Mythical Man-Month: Essays on Software Engineering is a book on software engineering and project management by Fred Brooks, whose central theme is that "adding manpower to a late software project makes it later"...
. - Buys Ballot's law – Concerned with the notion that the wind travels counterclockwise around low pressure zones in the Northern Hemisphere. Named for C. H. D. Buys Ballot, who published an empirical validationEmpirical validationAn empirical validation of a hypothesis is required for it togain acceptance in the scientific community. Normally this validation is achieved by the scientific method of hypothesis commitment, experimental design, peer review, adversarial review, reproduction of results, conference presentation...
of an existing theory, in 1857. - Byerlee's lawByerlee's lawByerlee's law is an experimentally derived law in physics that gives the stress circumstances in the Earth's crust at which fracturing along a geological fault takes place...
– Gives the stress circumstances in the Earth's crust at which fracturing along a geological fault takes place.
C–D
- Campbell's lawCampbell's LawCampbell's law is an adage developed by Donald T. Campbell:The social science principle of Campbell's law is sometimes used to point out the negative consequences of high-stakes testing in U.S...
– "The more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor." Named for Donald T. CampbellDonald T. CampbellDonald Thomas Campbell was an American social scientist. He is noted for his work in methodology. He coined the term "evolutionary epistemology" and developed a selectionist theory of human creativity.- Biography :...
(1916–1996) - Celine's lawsCeline's lawsCeline's Laws are a series of three laws regarding government and social interaction attributed to the fictional character Hagbard Celine from Robert Anton Wilson's Illuminatus! Trilogy. Celine, a gentleman anarchist, serves as a mouthpiece for Wilson's libertarian, anarchist and sometimes...
– Celine's laws are a series of three laws regarding government and social interaction attributed to the fictional character Hagbard Celine from Robert Anton Wilson's The Illuminatus! TrilogyThe Illuminatus! TrilogyThe Illuminatus! Trilogy is a series of three novels written by Robert Shea and Robert Anton Wilson first published in 1975. The trilogy is a satirical, postmodern, science fiction-influenced adventure story; a drug-, sex-, and magick-laden trek through a number of conspiracy theories, both...
. - Charles's lawCharles's lawCharles' law is an experimental gas law which describes how gases tend to expand when heated. It was first published by French natural philosopher Joseph Louis Gay-Lussac in 1802, although he credited the discovery to unpublished work from the 1780s by Jacques Charles...
– States that at constant pressure, the volume of a given mass of a gas increases or decreases by the same factor as its temperature (in kelvins) increases or decreases. Named for Jacques CharlesJacques CharlesJacques Alexandre César Charles was a French inventor, scientist, mathematician, and balloonist.Charles and the Robert brothers launched the world's first hydrogen-filled balloon in August 1783, then in December 1783, Charles and his co-pilot Nicolas-Louis Robert ascended to a height of about...
. - Clarke's three lawsClarke's three lawsClarke's Three Laws are three "laws" of prediction formulated by the British writer and scientist Arthur C. Clarke. They are:# When a distinguished but elderly scientist states that something is possible, he is almost certainly right...
– Formulated by Arthur C. ClarkeArthur C. ClarkeSir Arthur Charles Clarke, CBE, FRAS was a British science fiction author, inventor, and futurist, famous for his short stories and novels, among them 2001: A Space Odyssey, and as a host and commentator in the British television series Mysterious World. For many years, Robert A. Heinlein,...
. Several corollaries to these lawsClarke's three lawsClarke's Three Laws are three "laws" of prediction formulated by the British writer and scientist Arthur C. Clarke. They are:# When a distinguished but elderly scientist states that something is possible, he is almost certainly right...
have also been proposed.- First law: When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
- Second law: The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
- Third law: Any sufficiently advanced technology is indistinguishable from magic.
- Classen's lawClassen's lawClaasen's logarithmic law of usefulness is named after technologist Theo A. C. M. Claasen, who introduced the idea in 1999 when he was CTO of Philips Semiconductors:The law can also be expressed as:-Examples of Claasen's law:...
– Theo Classen's "logarithmic law of usefulness" – 'usefulness = log(technology)'. - Conway's lawConway's LawConway's Law is an adage named after computer programmer Melvin Conway, who introduced the idea in 1968:...organizations which design systems ... are constrained to produce designs which are copies of the communication structures of these organizations....
– Any piece of software reflects the organizational structure that produced it. Named for Melvin ConwayMelvin ConwayMelvin Edward Conway was an early computer scientist, computer programmer, and hacker who coined what's now known as Conway's Law: "Organizations which design systems are constrained to produce designs which are copies of the communication structures of these organizations."Apart from the above,...
. - Cooper's law – The number of radio frequency conversations which can be concurrently conducted in a given area doubles every 30 months.
- Cope's ruleCope's ruleCope's rule states that population lineages tend to increase in body size over evolutionary time. While the rule has been demonstrated in many instances, it does not hold true at all taxonomic levels, or in all clades...
– Population lineages tend to increase in body size over evolutionary time. - Coulomb's lawCoulomb's lawCoulomb's law or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. It was first published in 1785 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism...
– An inverse-square lawInverse-square lawIn physics, an inverse-square law is any physical law stating that a specified physical quantity or strength is inversely proportional to the square of the distance from the source of that physical quantity....
indicating the magnitude and direction of electrostaticElectrostaticsElectrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....
force that one stationary, electrically charged object of small dimensions (ideally, a point source) exerts on another. It is named after Charles-Augustin de CoulombCharles-Augustin de CoulombCharles-Augustin de Coulomb was a French physicist. He is best known for developing Coulomb's law, the definition of the electrostatic force of attraction and repulsion. The [SI unit] of charge, the coulomb, was named after him....
. - Dale's principleDale's principleIn neuroscience, Dale's Principle is a rule attributed to the English neuroscientist Henry Hallett Dale. The principle basically states that a neuron performs the same chemical action at all of its synaptic connections to other cells, regardless of the identity of the target cell...
– In neuroscienceNeuroscienceNeuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
, states that a neuron is capable of producing and secreting only one neurotransmitter from its axon terminals. Named after Henry Hallett DaleHenry Hallett DaleSir Henry Hallett Dale, OM, GBE, PRS was an English pharmacologist and physiologist. For his study of acetylcholine as agent in the chemical transmission of nerve impulses he shared the 1936 Nobel Prize in Physiology or Medicine with Otto Loewi.-Biography:Henry Hallett Dale was born in Islington,...
but more recent data suggests it to be false. - Dalton's lawDalton's lawIn chemistry and physics, Dalton's law states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures of each individual component in a gas mixture...
– In chemistryChemistryChemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
and physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, states that the total pressurePressurePressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
exerted by a gasGasGas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
eous mixture is equal to the sum of the partial pressurePartial pressureIn a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture....
s of each individual component in a gas mixture. Also called Dalton's law of partial pressure, and related to the idealIdeal gasAn ideal gas is a theoretical gas composed of a set of randomly-moving, non-interacting point particles. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics.At normal conditions such as...
gas lawsGas lawsThe early gas laws were developed at the end of the 18th century, when scientists began to realize that relationships between the pressure, volume and temperature of a sample of gas could be obtained which would hold for all gases...
, this empiricalEmpiricalThe word empirical denotes information gained by means of observation or experimentation. Empirical data are data produced by an experiment or observation....
law was observed by John DaltonJohn DaltonJohn Dalton FRS was an English chemist, meteorologist and physicist. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness .-Early life:John Dalton was born into a Quaker family at Eaglesfield, near Cockermouth, Cumberland,...
in 1801. - Darcy's lawDarcy's lawDarcy's law is a phenomenologically derived constitutive equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on the results of experiments on the flow of water through beds of sand...
– In hydrogeologyHydrogeologyHydrogeology is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth's crust, . The term geohydrology is often used interchangeably...
, describes the flow of a fluidFluidIn physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....
(such as waterWaterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
) through a porous mediumPorous mediumA porous medium is a material containing pores . The skeletal portion of the material is often called the "matrix" or "frame". The pores are typically filled with a fluid...
(such as an aquiferAquiferAn aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
). - Davis' law – In anatomyAnatomyAnatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
, describes how soft tissue models along imposed demands. Corollary to Wolff's lawWolff's lawWolff's law is a theory developed by the German Anatomist/Surgeon Julius Wolff in the 19th century that states that bone in a healthy person or animal will adapt to the loads it is placed under. If loading on a particular bone increases, the bone will remodel itself over time to become stronger...
. - De Morgan's laws – Apply to formal logicFormal logicClassical or traditional system of determining the validity or invalidity of a conclusion deduced from two or more statements...
regarding the negation of pairs of logical operators. - Dermott's law – The sidereal period of major satelliteSatelliteIn the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s tends to follow a geometric series. Named after Stanley Dermott. - Dilbert principle – Coined by Scott AdamsScott AdamsScott Raymond Adams is the American creator of the Dilbert comic strip and the author of several nonfiction works of satire, commentary, business, and general speculation....
as a variation of the Peter PrinciplePeter PrincipleThe Peter Principle states that "in a hierarchy every employee tends to rise to his level of incompetence", meaning that employees tend to be promoted until they reach a position at which they cannot work competently. It was formulated by Dr. Laurence J...
of employee advancement. Named after Adams' DilbertDilbertDilbert is an American comic strip written and drawn by Scott Adams. First published on April 16, 1989, Dilbert is known for its satirical office humor about a white-collar, micromanaged office featuring the engineer Dilbert as the title character...
comic strip, it proposes that "the most ineffective workers are systematically moved to the place where they can do the least damage: management." - Dollo's lawDollo's lawDollo's law of irreversibility is a hypothesis proposed in 1893 by French-born Belgian paleontologist Louis Dollo which states that evolution is not reversible...
– "An organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors." Simply put this law states that evolution is not reversible. - Dulong–Petit lawDulong–Petit lawThe Dulong–Petit law, a chemical law proposed in 1819 by French physicists Pierre Louis Dulong and Alexis Thérèse Petit, states the classical expression for the molar specific heat capacity of a crystal...
– States the classical expression for the specific heat capacity of a crystalCrystalA crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
due to its lattice vibrationPhononIn physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, such as solids and some liquids...
s. Named for Pierre Louis DulongPierre Louis DulongPierre Louis Dulong was a French physicist and chemist, remembered today largely for the law of Dulong and Petit. He worked on the specific heat capacity and the expansion and refractive indices of gases....
and Alexis Thérèse PetitAlexis Thérèse PetitAlexis Thérèse Petit was a French physicist. Petit is known for his work on the efficiencies of air- and steam-engines, published in 1818...
. - Dunbar's numberDunbar's numberDunbar's number is suggested to be a theoretical cognitive limit to the number of people with whom one can maintain stable social relationships. These are relationships in which an individual knows who each person is, and how each person relates to every other person...
– A theoretical cognitive limit to the number of people with whom one can maintain stable social relationships. No precise value has been proposed for Dunbar's number, but a commonly cited approximation is 150. First proposed by British anthropologist Robin DunbarRobin DunbarRobin Ian MacDonald Dunbar is a British anthropologist and evolutionary psychologist and a specialist in primate behaviour. He is currently Professor of Evolutionary Anthropology and the Director of the Institute of Cognitive and Evolutionary Anthropology of the University of Oxford and the...
. - Duverger's lawDuverger's lawIn political science, Duverger's law is a principle which asserts that a plurality rule election system tends to favor a two-party system. This is one of two hypotheses proposed by Duverger, the second stating that “the double ballot majority system and proportional representation tend to...
– After Maurice Duverger. Winner-take-all (or first-past-the-post) electoral systems tend to create a 2 party system, while proportional representation tends to create a multiple party system.
E–G
- Einasto's lawEinasto profileThe Einasto profile is a mathematical function that describes how the density \rho of a spherical stellar system varies with distance r from its center...
– Relates the density of a galaxy to distance from the center. Named for Jaan EinastoJaan EinastoJaan Einasto is an eminent Estonian astrophysicist and one of the discoverers of the cellular structure of the Universe....
. - Faraday's law of inductionFaraday's law of inductionFaraday's law of induction dates from the 1830s, and is a basic law of electromagnetism relating to the operating principles of transformers, inductors, and many types of electrical motors and generators...
– States that a magnetic fieldMagnetic fieldA magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
changing in time creates a proportional electromotive forceElectromotive forceIn physics, electromotive force, emf , or electromotance refers to voltage generated by a battery or by the magnetic force according to Faraday's Law, which states that a time varying magnetic field will induce an electric current.It is important to note that the electromotive "force" is not a...
. Named for Michael FaradayMichael FaradayMichael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....
, based on his work in 1831. - Faraday's law of electrolysis – States that the mass of a substance produced at an electrodeElectrodeAn electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit...
during electrolysisElectrolysisIn chemistry and manufacturing, electrolysis is a method of using a direct electric current to drive an otherwise non-spontaneous chemical reaction...
is proportional to the number of molesMole (unit)The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value...
of electrons transferred at that electrode; again named for Michael Faraday. - Fick's laws of diffusionFick's law of diffusionFick's laws of diffusion describe diffusion and can be used to solve for the diffusion coefficient, D. They were derived by Adolf Fick in the year 1855.- Fick's first law :...
– Describe diffusionDiffusionMolecular diffusion, often called simply diffusion, is the thermal motion of all particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size of the particles...
, and define the diffusion coefficient D. Derived by Adolf Fick in the year 1855. - Fitts' lawFitts' lawFitts's law is a model of human movement primarily used in human–computer interaction and ergonomics that predicts that the time required to rapidly move to a target area is a function of the distance to the target and the size of the target...
– A principle of human movement published in 1954 by Paul FittsPaul FittsPaul M. Fitts was a psychologist at Ohio State University . He developed a model of human movement, Fitts's law, based on rapid, aimed movement, which went on to become one of the most highly successful and well studied mathematical models of human motion...
which predicts the time required to move from a starting position to a final target area. Fitts' law is used to model the act of pointing, both in the real world, e.g. with a hand or finger, and on a computerComputerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
, e.g. with a mouse. - Fourier's law, also known as the law of heat conduction, states that the time rate of heat flow Q through a slab (or a portion of a perfectly insulated wire) is proportionalProportionality (mathematics)In mathematics, two variable quantities are proportional if one of them is always the product of the other and a constant quantity, called the coefficient of proportionality or proportionality constant. In other words, are proportional if the ratio \tfrac yx is constant. We also say that one...
to the gradientGradientIn vector calculus, the gradient of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change....
of temperature difference; named for Joseph FourierJoseph FourierJean Baptiste Joseph Fourier was a French mathematician and physicist best known for initiating the investigation of Fourier series and their applications to problems of heat transfer and vibrations. The Fourier transform and Fourier's Law are also named in his honour...
. - Gall's lawGall's lawGall's Law is a rule of thumb from John Gall's Systemantics: How Systems Really Work and How They Fail:Systemantics is a commentary on systems theory and general semantics publications by such thinkers as Ludwig von Bertalanffy and Alfred Korzybski.Although dubbed Gall's Law...
– "A complex systemComplex systemA complex system is a system composed of interconnected parts that as a whole exhibit one or more properties not obvious from the properties of the individual parts....
that works is invariably found to have evolved from a simple system that worked." - Gause's law – In ecologyEcologyEcology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
, the competitive exclusion principleCompetitive exclusion principleIn ecology, the competitive exclusion principle, sometimes referred to as Gause's law of competitive exclusion or just Gause's law, is a proposition which states that two species competing for the same resources cannot coexist if other ecological factors are constant...
: "complete competitors cannot coexist." - Gauss's lawGauss's lawIn physics, Gauss's law, also known as Gauss's flux theorem, is a law relating the distribution of electric charge to the resulting electric field. Gauss's law states that:...
– In physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, gives the relation between the electric fluxFluxIn the various subfields of physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks.* In the study of transport phenomena , flux is defined as flow per unit area, where flow is the movement of some quantity per time...
flowing out a closed surface and the chargeElectric chargeElectric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
enclosed in the surface. It was formulated by Carl Friedrich GaussCarl Friedrich GaussJohann Carl Friedrich Gauss was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum...
. See also Gauss' law for gravityGauss' law for gravityIn physics, Gauss's law for gravity, also known as Gauss's flux theorem for gravity, is a law of physics which is essentially equivalent to Newton's law of universal gravitation...
, and Gauss's law for magnetism. - Gay-Lussac's lawGay-Lussac's lawThe expression Gay-Lussac's law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes, the first listed here...
– "The pressure of a fixed mass and fixed volume of a gas is directly proportional to the gas's temperature." - Gibrat's lawGibrat's lawGibrat's law, sometimes called Gibrat's rule of proportionate growth is a rule defined by Robert Gibrat stating that the size of a firm and its growth rate are independent. The law proportionate growth gives rise to a distribution that is log-normal...
—"The size of a firm and its growth rate are independent." - Ginsberg's theoremGinsberg's TheoremGinsberg's theorem is a set of adages which restate the laws of thermodynamics in terms of a person playing a game. The quote is attributed to the poet Allen Ginsberg.-Theorem:...
– A set of adages based on the laws of thermodynamicsLaws of thermodynamicsThe four laws of thermodynamics summarize its most important facts. They define fundamental physical quantities, such as temperature, energy, and entropy, in order to describe thermodynamic systems. They also describe the transfer of energy as heat and work in thermodynamic processes...
. - Godwin's lawGodwin's LawGodwin's law is a humorous observation made by Mike Godwin in 1990 that has become an Internet adage...
– An adage in InternetInternetThe Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
culture that states, "As an online discussion grows longer, the probability of a comparison involving NazisNazismNazism, the common short form name of National Socialism was the ideology and practice of the Nazi Party and of Nazi Germany...
or Hitler approaches one." Coined by Mike GodwinMike GodwinMichael Wayne Godwin is an American attorney and author. He was the first staff counsel of the Electronic Frontier Foundation , and the creator of the Internet adage Godwin's Law of Nazi Analogies. From July 2007 to October 2010, he was general counsel for the Wikimedia Foundation...
in 1990. - Goodhart's lawGoodhart's lawGoodhart's law, although it can be expressed in many ways, states that once a social or economic indicator or other surrogate measure is made a target for the purpose of conducting social or economic policy, then it will lose the information content that would qualify it to play that role...
– When a measure becomes a target, it ceases to be a good measure. - Graham's lawGraham's lawGraham's law, known as Graham's law of effusion, was formulated by Scottish physical chemist Thomas Graham in 1846. Graham found experimentally that the rate of effusion of a gas is inversely proportional to the square root of the mass of its particles...
– In physics, a gas law which states that the average kinetic energyKinetic energyThe kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
of the molecules of two samples of different gases at the same temperature is identical. It is named for Thomas GrahamThomas Graham (chemist)Thomas Graham FRS was a nineteenth-century Scottish chemist who is best-remembered today for his pioneering work in dialysis and the diffusion of gases.- Life and work :...
(1805–1869), who formulated it. - Greenspun's Tenth RuleGreenspun's Tenth RuleGreenspun's tenth rule of programming is an aphorism in computer programming and especially programming language circles that states:This expresses the opinion that the perceived flexibility and extensibility designed into the Lisp programming language includes all functionality that is...
– Any sufficiently complicated C or Fortran program contains an ad hoc, informally specified, bug-ridden, slow implementation of half of Common Lisp; coined by Philip GreenspunPhilip GreenspunPhilip Greenspun is a semi-retired American computer scientist, educator, and early Internet entrepreneur who was a pioneer in developing online communities.-Biography:...
. - Gresham's lawGresham's LawGresham's law is an economic principle that states: "When a government compulsorily overvalues one type of money and undervalues another, the undervalued money will leave the country or disappear from circulation into hoards, while the overvalued money will flood into circulation." It is commonly...
– Typically stated as "Bad money drives good money out of circulation", but more accurately "Bad money drives good money out of circulation if their exchange rate is set by law." Coined in 1858 by British economist Henry Dunning MacleodHenry Dunning Macleod-Life:Henry Dunning Macleod was born in Edinburgh, and educated at Eton, Edinburgh University, and Trinity College, Cambridge, where he graduated in 1843. Macleod traveled in Europe, and in 1849 was called to the English bar. He was employed in Scotland on the work of poor-law reform, and devoted...
, and named for Sir Thomas GreshamThomas GreshamSir Thomas Gresham was an English merchant and financier who worked for King Edward VI of England and for Edward's half-sisters, Queens Mary I and Elizabeth I.-Family and childhood:...
(1519–1579). The principle had been stated before Gresham by others, including Nicolaus CopernicusNicolaus CopernicusNicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....
. - Grimm's lawGrimm's lawGrimm's law , named for Jacob Grimm, is a set of statements describing the inherited Proto-Indo-European stops as they developed in Proto-Germanic in the 1st millennium BC...
– Explains correspondence between some consonants in Germanic languages and those in other Indo-European languages. Discovered by Jacob GrimmJacob GrimmJacob Ludwig Carl Grimm was a German philologist, jurist and mythologist. He is best known as the discoverer of Grimm's Law, the author of the monumental Deutsches Wörterbuch, the author of Deutsche Mythologie and, more popularly, as one of the Brothers Grimm, as the editor of Grimm's Fairy...
, (1785–1863), GermanGermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
philologist and mythologistMythologyThe term mythology can refer either to the study of myths, or to a body or collection of myths. As examples, comparative mythology is the study of connections between myths from different cultures, whereas Greek mythology is the body of myths from ancient Greece...
and one of the Brothers GrimmBrothers GrimmThe Brothers Grimm , Jacob Grimm and Wilhelm Grimm , were German academics, linguists, cultural researchers, and authors who collected folklore and published several collections of it as Grimm's Fairy Tales, which became very popular...
. - Grosch's lawGrosch's lawGrosch's law is the following observation about computer performance made by Herb Grosch in 1965:There is a fundamental rule, which I modestly call Grosch's law, giving added economy only as the square root of the increase in speed -- that is, to do a calculation 10 times as cheaply you must do it...
– Herb GroschHerb GroschHerbert Reuben John Grosch was an early computer scientist, perhaps best known for Grosch's law, which he formulated in 1950. Grosch's Law is an aphorism that states "economy is as the square root of the speed."...
in 1965 argued that the economic value of computation increases with the square root of the increase in speed—that is, to do a calculation 10 times as cheaply you must do it 100 times as fast. - Gustafson's lawGustafson's lawGustafson's Law is a law in computer science which says that problems with large, repetitive data sets can be efficiently parallelized. Gustafson's Law contradicts Amdahl's law, which describes a limit on the speed-up that parallelization can provide. Gustafson's law was first described by John...
(also known as Gustafson–Barsis' law) – a law in computer engineeringComputer engineeringComputer engineering, also called computer systems engineering, is a discipline that integrates several fields of electrical engineering and computer science required to develop computer systems. Computer engineers usually have training in electronic engineering, software design, and...
, that any sufficiently large problem can be efficiently parallelizedParallel computingParallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...
. Coined by John Gustafson in 1988.
H–K
- Hanlon's razorHanlon's razorHanlon's Razor is an eponymous adage that reads:This particular form is attributed to a Robert J. Hanlon. However, earlier utterances that convey basically the same idea are known.-Origins and similar quotations:The quotation first came from Robert J...
– A corollary of Finagle's lawFinagle's lawFinagle's Law of Dynamic Negatives is usually rendered:One variant favored among hackers is a takeoff on the second law of thermodynamics :The term "Finagle's Law" was first used by John W...
, and a play on Occam's razorOccam's razorOccam's razor, also known as Ockham's razor, and sometimes expressed in Latin as lex parsimoniae , is a principle that generally recommends from among competing hypotheses selecting the one that makes the fewest new assumptions.-Overview:The principle is often summarized as "simpler explanations...
, normally taking the form, "Never attribute to malice that which can be adequately explained by stupidity." As with Finagle, possibly not strictly eponymous. Alternatively, "Do not invoke conspiracy as explanation when ignorance and incompetence will suffice, as conspiracy implies intelligence." - Hartley's law – a way to quantify information and its line rate in an analog communications channel. Named for Ralph HartleyRalph HartleyRalph Vinton Lyon Hartley was an electronics researcher. He invented the Hartley oscillator and the Hartley transform, and contributed to the foundations of information theory.-Biography:...
(1888–1970). - Hauser's lawHauser's LawHauser's law is the proposition that, in the United States, federal tax revenues since World War II have always been approximately equal to 19.5% of GDP, regardless of wide fluctuations in the marginal tax rate.- Historic tax revenues :...
– empirical observation about U.S. tax receipts as a percentage of GDP, theorized to be a natural equilibrium. - Hawthorne effectHawthorne effectThe Hawthorne effect is a form of reactivity whereby subjects improve or modify an aspect of their behavior being experimentally measured simply in response to the fact that they know they are being studied, not in response to any particular experimental manipulation.The term was coined in 1950 by...
– A form of reactivityReactivity (psychology)Reactivity is a phenomenon that occurs when individuals alter their performance or behavior due to the awareness that they are being observed. The change may be positive or negative, and depends on the situation. It is a significant threat to a research study's internal validity and is typically...
whereby subjects improve an aspect of their behavior being experimentally measured simply in response to the fact that they are being studied. Named after Hawthorne WorksHawthorne WorksThe Hawthorne Works, in Cicero, Illinois, was a large factory complex built by Western Electric starting in 1905 and operating until 1983. It had 45,000 employees at the height of its operations. Besides telephone equipment, the factory produced a wide variety of consumer products, including...
. - Heisenberg's Uncertainty principleUncertainty principleIn quantum mechanics, the Heisenberg uncertainty principle states a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known...
– States that one cannot measure values (with arbitrary precision) of certain conjugate quantities, which are pairs of observables of a single elementary particle. The most familiar of these pairs is position and momentum. - Hebb's law – "Neurons that fire together wire together."
- Henry's lawHenry's lawIn physics, Henry's law is one of the gas laws formulated by William Henry in 1803. It states that:An equivalent way of stating the law is that the solubility of a gas in a liquid at a particular temperature is proportional to the pressure of that gas above the liquid...
– The massMassMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of a gasGasGas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
that dissolves in a definite volumeVolumeVolume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
of liquidLiquidLiquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
is directly proportional to the pressurePressurePressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
of the gas provided the gas does not react with the solventSolventA solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
. - HerblockHerblockHerbert Lawrence Block, commonly known as Herblock , was an American editorial cartoonist and author best known for his commentary on national domestic and foreign policy from a liberal perspective.-Career:...
's law – "If it's good, they'll stop making it." Possibly coined by Herbert Lawrence Block, whose pen name was HerblockHerblockHerbert Lawrence Block, commonly known as Herblock , was an American editorial cartoonist and author best known for his commentary on national domestic and foreign policy from a liberal perspective.-Career:...
. - Hick's lawHick's lawHick's Law, named after British psychologist William Edmund Hick, or the Hick–Hyman Law , describes the time it takes for a person to make a decision as a result of the possible choices he or she has. The Hick-Hyman Law assesses cognitive information capacity in choice reaction experiments...
– In psychology, the time it takes for a person to make a decision as a result of the possible choices he or she has. - Hofstadter's lawHofstadter's lawHofstadter's law is a self-referencing time-related adage, coined by Douglas Hofstadter and named after himself.Hofstadter's Law was a part of Douglas Hofstadter's 1979 book Gödel, Escher, Bach: An Eternal Golden Braid. The law is a statement regarding the difficulty of accurately estimating the...
– "It always takes longer than you expect, even when you take into account Hofstadter's Law" (Douglas HofstadterDouglas HofstadterDouglas Richard Hofstadter is an American academic whose research focuses on consciousness, analogy-making, artistic creation, literary translation, and discovery in mathematics and physics...
, Gödel, Escher, BachGödel, Escher, BachGödel, Escher, Bach: An Eternal Golden Braid is a book by Douglas Hofstadter, described by his publishing company as "a metaphorical fugue on minds and machines in the spirit of Lewis Carroll"....
, 1979). - Hooke's lawHooke's lawIn mechanics, and physics, Hooke's law of elasticity is an approximation that states that the extension of a spring is in direct proportion with the load applied to it. Many materials obey this law as long as the load does not exceed the material's elastic limit. Materials for which Hooke's law...
– The tension on a spring or other elastic object is proportional to the displacement from the equilibrium. Frequently cited in Latin as "Ut tensio sic vis." Named after Robert HookeRobert HookeRobert Hooke FRS was an English natural philosopher, architect and polymath.His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666, but...
(1635–1703). - Hotelling's lawHotelling's lawHotelling's law is an observation in economics that in many markets it is rational for producers to make their products as similar as possible. This is also referred to as the principle of minimum differentiation as well as Hotelling's "linear city model"...
in economicsEconomicsEconomics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...
– Under some conditions, it is rational for competitors to make their products as nearly identical as possible. - Hubble's lawHubble's lawHubble's law is the name for the astronomical observation in physical cosmology that: all objects observed in deep space are found to have a doppler shift observable relative velocity to Earth, and to each other; and that this doppler-shift-measured velocity, of various galaxies receding from...
– Galaxies recede from an observer at a rate proportional to their distance to that observer. Formulated by Edwin HubbleEdwin HubbleEdwin Powell Hubble was an American astronomer who profoundly changed the understanding of the universe by confirming the existence of galaxies other than the Milky Way - our own galaxy...
in 1929. - Humphrey's law – conscious attention to a task normally performed automatically can impair its performance. Described by psychologist George Humphrey in 1923.
- Hutber's lawHutber's lawHutber's law states that "improvement means deterioration". It is founded on the cynical observation that a stated improvement actually hides a deterioration.The term has seen wide application in business, engineering, and risk analysis...
– "Improvement means deterioration." Coined by financial journalist Patrick Hutber. - Hume's law – In meta-ethicsMeta-ethicsIn philosophy, meta-ethics is the branch of ethics that seeks to understand the nature of ethical properties, statements, attitudes, and judgments. Meta-ethics is one of the three branches of ethics generally recognized by philosophers, the others being normative ethics and applied ethics. Ethical...
, the assertion that normative statements cannot be deduced exclusively from descriptive statements. - Isaac Bonewits's laws of magicIsaac BonewitsPhillip Emmons Isaac Bonewits was an influential American Druid who published a number of books on the subject of Neopaganism and magic. He was also a liturgist, singer and songwriter, and founded the Druidic organisation Ár nDraíocht Féin, as well as the Neopagan civil rights group, the Aquarian...
– "Laws" synthesized from a multitude of belief systems from around the world, collected in order to explain and categorize magical beliefs within a cohesive framework, by Isaac BonewitsIsaac BonewitsPhillip Emmons Isaac Bonewits was an influential American Druid who published a number of books on the subject of Neopaganism and magic. He was also a liturgist, singer and songwriter, and founded the Druidic organisation Ár nDraíocht Féin, as well as the Neopagan civil rights group, the Aquarian...
. - Joule's laws – Heat laws related to electricity and to gasses, named for James Prescott JouleJames Prescott JouleJames Prescott Joule FRS was an English physicist and brewer, born in Salford, Lancashire. Joule studied the nature of heat, and discovered its relationship to mechanical work . This led to the theory of conservation of energy, which led to the development of the first law of thermodynamics. The...
. - Kepler's laws of planetary motionKepler's laws of planetary motionIn astronomy, Kepler's laws give a description of the motion of planets around the Sun.Kepler's laws are:#The orbit of every planet is an ellipse with the Sun at one of the two foci....
– Describe the motion of the planets around the sun. First articulated by Johannes KeplerJohannes KeplerJohannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...
. - Kerckhoffs' principleKerckhoffs' principleIn cryptography, Kerckhoffs's principle was stated by Auguste Kerckhoffs in the 19th century: A cryptosystem should be secure even if everything about the system, except the key, is public knowledge.Kerckhoffs's principle was reformulated by Claude Shannon as...
of secure cryptography – A cryptosystem should be secure even if everything about the system, except the key, is public knowledge. - Keynes's law – Demand creates its own supply.
- Kirchhoff's lawsKirchhoff's lawsThere are several Kirchhoff's laws, all named after Gustav Robert Kirchhoff:* Kirchhoff's circuit laws* Kirchhoff's law of thermal radiation* Kirchhoff's equations* Kirchhoff's three laws of spectroscopy* Kirchhoff's law of thermochemistry-See also:...
– One law in thermodynamics and two about electrical circuits, named after Gustav KirchhoffGustav KirchhoffGustav Robert Kirchhoff was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects...
. - Koomey's lawKoomey's lawKoomey’s law describes a long-term trend in the history of computing hardware. The number of computations per joule of energy dissipated has been doubling approximately every 1.57 years. This trend has been remarkably stable since the 1950s and has actually been somewhat faster than Moore’s law...
– That the energy of computation is halved every year and a half. - Kopp's lawKopp's LawKopp's law can refer to either of two relationships discovered by the German chemist Hermann Franz Moritz Kopp .#Kopp found "that the molecular heat capacity of a solid compound is the sum of the atomic heat capacities of the elements composing it; the elements having atomic heat capacities lower...
– The molecular heat capacity of a solid compound is the sum of the atomic heat capacities of the elements composing it. Named for Hermann Franz Moritz KoppHermann Franz Moritz KoppHermann Franz Moritz Kopp , German chemist, was born at Hanau, where his father, Johann Heinrich Kopp , a physician, was professor of chemistry, physics and natural history at the local lyceum....
. - Kranzberg's first law of technologyKranzberg's laws of technologyMelvin Kranzberg's six laws of technology state:#Technology is neither good nor bad; nor is it neutral.#Invention is the mother of necessity.#Technology comes in packages, big and small....
– Technology is neither good nor bad; nor is it neutral.
L–M
- Leibniz's law – A principle in metaphysicsMetaphysicsMetaphysics is a branch of philosophy concerned with explaining the fundamental nature of being and the world, although the term is not easily defined. Traditionally, metaphysics attempts to answer two basic questions in the broadest possible terms:...
also known as the Identity of Indiscernibles. It states: "If two objects have all their properties in common, then they are one and the same object." - Lenz's lawLenz's lawLenz's law is a common way of understanding how electromagnetic circuits must always obey Newton's third law and The Law of Conservation of Energy...
– An induced current is always in such a direction as to oppose the motion or change causing it. - Linus' law – "Given enough eyeballs, all bugs are shallow." Named for Linus TorvaldsLinus TorvaldsLinus Benedict Torvalds is a Finnish software engineer and hacker, best known for having initiated the development of the open source Linux kernel. He later became the chief architect of the Linux kernel, and now acts as the project's coordinator...
. - Little's lawLittle's lawIn the mathematical theory of queues, Little's result, theorem, lemma, law or formula says:It is a restatement of the Erlang formula, based on the work of Danish mathematician Agner Krarup Erlang...
– In queuing theory, "The average number of customers in a stable system (over some time interval) is equal to their average arrival rate, multiplied by their average time in the system." The law was named for John Little from results of experiments in 1961. - Littlewood's lawLittlewood's lawLittlewood's Law states that individuals can expect a "miracle" to happen to them at the rate of about one per month.-History:The law was framed by Cambridge University Professor J. E...
– States that individuals can expect miracles to happen to them, at the rate of about one per month. Coined by Professor J E LittlewoodJohn Edensor LittlewoodJohn Edensor Littlewood was a British mathematician, best known for the results achieved in collaboration with G. H. Hardy.-Life:...
, (1885–1977). - Lotka's law – In infometrics, states that the number of authors publishing a certain number of articles is a fixed ratio to the number of authors publishing a single article. As the number of articles published increases, authors producing that many publications become less frequent. For example, there may be 1/4 as many authors publishing two articles within a specified time period as there are single-publication authors, 1/9 as many publishing three articles, 1/16 as many publishing four articles, etc. Though the law itself covers many disciplines, the actual ratios involved are very discipline-specific.
- Marconi's lawMarconi's lawMarconi's law is the relation between height of antennae and maximum signalling distance. Guglielmo Marconi enunciated at one time an empirical law that, for simple vertical sending and receiving antennae of equal height, the maximum working telegraphic distance varied as the square of the height...
– An empirical law that relates radio communication distance to antenna tower height - Meadow's lawMeadow's lawMeadow's Law was a precept much in use until recently in the field of child protection, specifically by those investigating cases of multiple cot or crib death — SIDS — within a single family.-History:...
– A precept, now discredited, that since cot deaths are so rare, "One is a tragedy, two is suspicious and three is murderMurderMurder is the unlawful killing, with malice aforethought, of another human being, and generally this state of mind distinguishes murder from other forms of unlawful homicide...
, until proved otherwise." It was named for Sir Roy MeadowRoy MeadowSir Samuel Roy Meadow is a British paediatrician and professor, who rose to initial fame for his 1977 academic paper on the now controversial Munchausen Syndrome by Proxy and his crusade against parents who, he believes, wilfully harm or kill their children. He was knighted for these works...
, a discredited paediatrician prominent in the United Kingdom in the last quarter of the twentieth century. - Mendel's lawsMendelian inheritanceMendelian inheritance is a scientific description of how hereditary characteristics are passed from parent organisms to their offspring; it underlies much of genetics...
– Named for the 19th century Austrian monk Gregor MendelGregor MendelGregor Johann Mendel was an Austrian scientist and Augustinian friar who gained posthumous fame as the founder of the new science of genetics. Mendel demonstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance...
who determined the patterns of inheritance through his plant breeding experiments, working especially with peas. Mendel's first law, or the law of segregation, states that each organism has a pair of genesGênesGênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...
; that that it inherits one from each parent, and that the organism will pass down only one of these genes to its own offspring. These different copies of the same gene are called alleles. Mendel's second law, the law of independent assortment, states that different traits will be inherited independently by the offspring. - Metcalfe's lawMetcalfe's lawMetcalfe's law states that the value of a telecommunications network is proportional to the square of the number of connected usersof the system...
– In communicationCommunicationCommunication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...
s and network theoryNetwork theoryNetwork theory is an area of computer science and network science and part of graph theory. It has application in many disciplines including statistical physics, particle physics, computer science, biology, economics, operations research, and sociology...
, states that the value of a system grows as approximately the square of the number of users of the system. Framed by Robert MetcalfeRobert MetcalfeRobert Melancton Metcalfe is an electrical engineer from the United States who co-invented Ethernet, founded 3Com and formulated Metcalfe's Law., he is a general partner of Polaris Venture Partners...
in the context of ethernetEthernetEthernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
. - Mooers' lawMooers' LawMooers' Law is an empirical observation of behavior made by American computer scientist Calvin Mooers in 1959. The observation is made in relation to information retrieval and the interpretation of the observation is used commonly throughout the information profession both within and outside its...
– "An information retrieval system will tend not to be used whenever it is more painful and troublesome for a customer to have information than for him not to have it." An empirical observation made by American computer scientistComputer scientistA computer scientist is a scientist who has acquired knowledge of computer science, the study of the theoretical foundations of information and computation and their application in computer systems....
Calvin MooersCalvin MooersCalvin Northrup Mooers , was an American computer scientist known for his work in information retrieval and for the programming language TRAC....
in 1959. - Moore's lawMoore's LawMoore's law describes a long-term trend in the history of computing hardware: the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every two years....
– An empirical observation stating that the complexity of integrated circuitIntegrated circuitAn integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s doubles every 24 months. Outlined in 1965 by Gordon MooreGordon MooreGordon Earle Moore is the co-founder and Chairman Emeritus of Intel Corporation and the author of Moore's Law .-Life and career:...
, co-founder of IntelIntel CorporationIntel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...
. - Muphry's lawMuphry's lawMuphry's law is an adage that states that "if you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written"...
– "If you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written." The editorial equivalent of Murphy's lawMurphy's lawMurphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong". - History :The perceived perversity of the universe has long been a subject of comment, and precursors to the modern version of Murphy's law are not hard to find. Recent significant...
, according to John BangsundJohn BangsundJohn Bangsund was a prominent Australian science fiction fan in the 1960s, 1970s and 1980s. He was a major force, with Andrew I. Porter behind Australia winning the right to host the 1975 Aussiecon, and he was Toastmaster at the Hugo Award ceremony at that convention.He was an influential and...
. - Murphy's lawMurphy's lawMurphy's law is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong". - History :The perceived perversity of the universe has long been a subject of comment, and precursors to the modern version of Murphy's law are not hard to find. Recent significant...
– "Anything that can go wrong will go wrong." Ascribed to Edward A. Murphy, Jr.
N–Q
- Newton's law of cooling – The rate of cooling (or heating) of a body due to convection is proportional to the difference between the body temperature and the ambient temperature.
- Newton's laws of motionNewton's laws of motionNewton's laws of motion are three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces...
– In physics, three scientific laws concerning the behaviour of moving bodiesMotion (physics)In physics, motion is a change in position of an object with respect to time. Change in action is the result of an unbalanced force. Motion is typically described in terms of velocity, acceleration, displacement and time . An object's velocity cannot change unless it is acted upon by a force, as...
, which are fundamental to classical mechanicsClassical mechanicsIn physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces...
(and since EinsteinAlbert EinsteinAlbert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
, which are valid only within inertial reference frames). Discovered and stated by Isaac NewtonIsaac NewtonSir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
(1643–1727), they can be formulated, in modern terms, as follows:- First law: "A body remains at rest, or keeps moving in a straight line (at a constant velocity), unless acted upon by a net outside force."
- Second law: "The acceleration of an object of constant mass is proportional to the net force acting upon it."
- Third law: "Whenever one body exerts a force upon a second body, the second body exerts an equal and opposite force upon the first body."
- Niven's lawsNiven's lawsNiven’s laws were named after science fiction author Larry Niven, who has periodically published them as "how the Universe works" as far as he can tell. These were most recently rewritten on January 29, 2002...
: "If the universe of discourse permits the possibility of time travel and of changing the past, then no time machine will be invented in that universe." - Nyquist rateNyquist rateIn signal processing, the Nyquist rate, named after Harry Nyquist, is two times the bandwidth of a bandlimited signal or a bandlimited channel...
– The minimum sampling rate required to avoid aliasing, equal to twice the highest frequency contained within the signal. Named after Harry NyquistHarry NyquistHarry Nyquist was an important contributor to information theory.-Personal life:...
. - Occam's razorOccam's razorOccam's razor, also known as Ockham's razor, and sometimes expressed in Latin as lex parsimoniae , is a principle that generally recommends from among competing hypotheses selecting the one that makes the fewest new assumptions.-Overview:The principle is often summarized as "simpler explanations...
– States that explanations should never multiply causes without necessity. ("Entia non sunt multiplicanda praeter necessitatem.") When two explanations are offered for a phenomenon, the simplest full explanation is preferable. Named after William of OckhamWilliam of OckhamWilliam of Ockham was an English Franciscan friar and scholastic philosopher, who is believed to have been born in Ockham, a small village in Surrey. He is considered to be one of the major figures of medieval thought and was at the centre of the major intellectual and political controversies of...
(ca.1285–1349). - Ohm's lawOhm's lawOhm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points...
– In physics, states that the ratio of the potential difference (or voltageVoltageVoltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
drop) between the ends of a conductor (and resistorResistorA linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
) to the current flowing through it is a constant, provided the temperature also does not change. Discovered and named after Georg Simon Ohm (1789–1854). - Ohm's acoustic lawOhm's acoustic lawOhm's acoustic law, sometimes called the acoustic phase law or simply Ohm's law, states that a musical sound is perceived by the ear as a set of a number of constituent pure harmonic tones.The law was proposed by physicist Georg Ohm in 1843...
– an empirical approximation concerning the perception of musical tones, also named for Georg Simon Ohm. - Okun's lawOkun's lawIn economics, Okun's law is an empirically observed relationship relating unemployment to losses in a country's production first quantified by Arthur M. Okun. The "gap version" states that for every 1% increase in the unemployment rate, a country's GDP will be at an additional roughly 2% lower...
– In economics, this refers to the trend that every time unemployment increases by 1%, a 2% decrease in the annual GDP occurs. - Orgel's ruleOrgel's ruleOrgel's rules are a set of axioms attributed to the evolutionary biologist Leslie Orgel.-Orgel's First Rule:"Whenever a spontaneous process is too slow or too inefficient a protein will evolve to speed it up or make it more efficient."...
s – In evolutionary biology, a set of axioms attributed to the evolutionary biologist Leslie OrgelLeslie OrgelLeslie Eleazer Orgel FRS was a British chemist.Born in London, England, Orgel received his B.A. in chemistry with first class honours from Oxford University in 1949...
.- First rule: "Whenever a spontaneous process is too slow or too inefficient a protein will evolve to speed it up or make it more efficient."
- Second rule: "Evolution is cleverer than you are."
- Pareto optimality – Given an initial allocation of goods among a set of individuals, a change to a different allocation that makes at least one individual better off without making any other individual worse off is called a Pareto improvement. An allocation is defined as "Pareto efficient" or "Pareto optimal" when no further Pareto improvements can be made.
- Pareto principlePareto principleThe Pareto principle states that, for many events, roughly 80% of the effects come from 20% of the causes.Business-management consultant Joseph M...
– States that for many phenomena 80% of consequences stem from 20% of the causes. Named after Italian economist Vilfredo ParetoVilfredo ParetoVilfredo Federico Damaso Pareto , born Wilfried Fritz Pareto, was an Italian engineer, sociologist, economist, political scientist and philosopher. He made several important contributions to economics, particularly in the study of income distribution and in the analysis of individuals' choices....
, but framed by management thinker Joseph M. Juran. - Parkinson's lawParkinson's lawParkinson's law is the adage first articulated by Cyril Northcote Parkinson as the first sentence of a humorous essay published in The Economist in 1955:...
– "Work expands so as to fill the time available for its completion." Coined by C. Northcote Parkinson (1909–1993), who also coined its corollary, "Expenditure rises to meet income." In computers: Programs expand to fill all available memory. - Peter PrinciplePeter PrincipleThe Peter Principle states that "in a hierarchy every employee tends to rise to his level of incompetence", meaning that employees tend to be promoted until they reach a position at which they cannot work competently. It was formulated by Dr. Laurence J...
– "In a hierarchy, every employee tends to rise to his level of incompetence." Coined by Dr. Laurence J. Peter (1919–1990) in his book The Peter Principle. In his follow-up book, The Peter Prescription, he offered possible solutions to the problems his Principle could cause. - Planck's law – In physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, given a black bodyBlack bodyA black body is an idealized physical body that absorbs all incident electromagnetic radiation. Because of this perfect absorptivity at all wavelengths, a black body is also the best possible emitter of thermal radiation, which it radiates incandescently in a characteristic, continuous spectrum...
at a given temperature, describes the spectral radiance of the object. After Max PlanckMax PlanckMax Karl Ernst Ludwig Planck, ForMemRS, was a German physicist who actualized the quantum physics, initiating a revolution in natural science and philosophy. He is regarded as the founder of the quantum theory, for which he received the Nobel Prize in Physics in 1918.-Life and career:Planck came...
. - Plateau's lawsPlateau's lawsPlateau's laws describe the structure of soap films. These laws were formulated in the 19th century by the Belgian physicist Joseph Plateau from his experimental observations.Plateau's laws state:# Soap films are made of entire smooth surfaces....
– Describe the structure of soap filmSoap filmSoap films are thin layers of liquid surrounded by air. For example, if two soap bubbles enters in contact, they merged and a thin film is created in between. Thus, foams are composed of a network of films connected by Plateau borders...
s. Named after Belgian physicist Joseph Plateau. - Poe's law (poetry) – There is a maximum desirable length for poems: "The unit of poetry must be fixed by the reader's capacity of attention, and ... the limits of a poem must accord with the limits of a single movement of intellectual apprehension and emotional exaltation," named for Edgar Allan PoeEdgar Allan PoeEdgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...
. See "The Philosophy of CompositionThe Philosophy of Composition"The Philosophy of Composition" is an 1846 essay written by American writer Edgar Allan Poe that elucidates a theory about how good writers write when they write well. He concludes that length, "unity of effect" and a logical method are important considerations for good writing. He also makes the...
".
- Poe's lawPoe's lawPoe's law, named after its author Nathan Poe, is an Internet adage reflecting the fact that without a clear indication of the author's intent, it is difficult or impossible to tell the difference between sincere extremism and an exaggerated parody of extremism....
(religious fundamentalism) – "Without a winking smiley or other blatant display of humour, it is impossible to create a parody of fundamentalism that someone won't mistake for the real thing." named after Nathan Poe who formulated it on the Web site Christian Forums in 2005. Although it originally referred to creationismCreationismCreationism is the religious beliefthat humanity, life, the Earth, and the universe are the creation of a supernatural being, most often referring to the Abrahamic god. As science developed from the 18th century onwards, various views developed which aimed to reconcile science with the Genesis...
, the scope later widened to religious fundamentalism. - Poisson's law of large numbers – For independent random variables with a common distribution, the average value for a sample tends to the mean as sample size increases. Named after Siméon-Denis Poisson (1781–1840) and derived from "Recherches sur la probabilité des jugements en matière criminelle et en matière civile" (1837; "Research on the Probability of Criminal and Civil Verdicts").
- Postel's law – Be conservative in what you do; be liberal in what you accept from others. Derived from RFC 761 (Transmission Control ProtocolTransmission Control ProtocolThe Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...
, 1980) in which Jon PostelJon PostelJonathan Bruce Postel was an American computer scientist who made many significant contributions to the development of the Internet, particularly with respect to standards...
summarized earlier communications of desired interoperability criteria for the Internet ProtocolInternet ProtocolThe Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
(cf. IEN 111) - Premack's principlePremack's principlePremack's principle, or the relativity theory of reinforcement,states that more probable behaviors will reinforce less probable behaviors. The principle was derived from a study of Cebus monkeys by Professor David Premack, but has explanatory and predictive power when applied to humans. This is...
– More probable behaviors will reinforce less probable behaviors. Named by David PremackDavid PremackDavid Premack is currently emeritus professor of psychology at the University of Pennsylvania. He was educated at the University of Minnesota when logical positivism was in full bloom. The departments of Psychology and Philosophy were closely allied...
(1925 – )
R–S
- Raoult's law – In chemistryChemistryChemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, Raoult's law states that the vapor pressureVapor pressureVapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system. All liquids have a tendency to evaporate, and some solids can sublimate into a gaseous form...
of mixed liquidLiquidLiquid is one of the three classical states of matter . Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly...
s is dependent on the vapor pressures of the individual liquids and the molar vulgar fraction of each present in solution. - Reed's lawReed's lawReed's law is the assertion of David P. Reed that the utility of large networks, particularly social networks, can scale exponentially with the size of the network....
– The assertion of David P. Reed that the utilityUtilityIn economics, utility is a measure of customer satisfaction, referring to the total satisfaction received by a consumer from consuming a good or service....
of large networks, particularly social networkSocial networkA social network is a social structure made up of individuals called "nodes", which are tied by one or more specific types of interdependency, such as friendship, kinship, common interest, financial exchange, dislike, sexual relationships, or relationships of beliefs, knowledge or prestige.Social...
s, can scale exponentiallyExponential growthExponential growth occurs when the growth rate of a mathematical function is proportional to the function's current value...
with the size of the network. - Reilly's law of retail gravitationReilly's law of retail gravitationIn economics, Reilly's law of retail gravitation states that larger cities will have larger spheres of influence than smaller ones, meaning people travel farther to reach a larger city....
– People generally patronize the largest mall in the area. - Roemer's lawRoemer's lawIn health policy, Roemer's Law may be expressed as follows: "in an insured population, a hospital bed built is a bed filled" This rule was deduced by the American health services researcher Milton Roemer, working at the UCLA School of Public Health...
– A hospital bed built is a bed filled. - Rothbard's law – Everyone specializes in his own area of weakness.
- Sarnoff's lawSarnoff's lawSarnoff's law states that the value of a broadcast network is directly proportional to the number of viewers. It is attributed to David Sarnoff.For example, a network with 100 members is 10 times as valuable as a network with 10 members.-See also:...
– The value of a broadcast network is proportional to the number of viewers. - Say's lawSay's lawSay's law, or the law of market, is an economic principle of classical economics named after the French businessman and economist Jean-Baptiste Say , who stated that "products are paid for with products" and "a glut can take place only when there are too many means of production applied to one kind...
– Attributed to economistEconomicsEconomics is the social science that analyzes the production, distribution, and consumption of goods and services. The term economics comes from the Ancient Greek from + , hence "rules of the house"...
Jean-Baptiste SayJean-Baptiste SayJean-Baptiste Say was a French economist and businessman. He had classically liberal views and argued in favor of competition, free trade, and lifting restraints on business...
and contrasted to Keynes' law (discussed hereinbefore), saying that "supply creates its own demand", i.e., if businesses produce more output in a free market economy, the wages and other payment for productive inputs will provide sufficient demand so that there is no general glutGeneral glutIn macroeconomics, a general glut is when supply exceeds demand, specifically, when there is more production in all fields of production in comparison with what resources are available to consume said production....
. - Sayre's lawSayre's LawSayre's law states, in a formulation quoted by Charles Philip Issawi: "In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake." By way of corollary, it adds: "That is why academic politics are so bitter." Sayre's law is named after Wallace Stanley...
– "In any dispute the intensity of feeling is inversely proportional to the value of the stakes at issue." By way of corollary, the law adds: "That is why academic politics are so bitter." - Schneier's lawSchneier's LawThe term Schneier's Law was coined by Cory Doctorow in his speech about Digital Rights Management for Microsoft Research, which is included in his 2008 book Content: Selected Essays on Technology, Creativity, Copyright, and the Future of the Future...
– "Any person can invent a security system so clever that she or he can't think of how to break it." - Segal's lawSegal's lawSegal's law is an adage that states:It refers to the potential pitfalls of having too much conflicting information when making a decision....
– "A man with a watch knows what time it is. A man with two watches is never sure." - Shermer's last lawShermer's Last LawShermer's last law is:"Any sufficiently advanced ETI is indistinguishable from God." It's Michael Shermer's modification of the third law of Arthur C. Clarke's famous three laws...
– A corollary of Clarke's three lawsClarke's three lawsClarke's Three Laws are three "laws" of prediction formulated by the British writer and scientist Arthur C. Clarke. They are:# When a distinguished but elderly scientist states that something is possible, he is almost certainly right...
, it states that "Any sufficiently advanced alien intelligence is indistinguishable from God." Originally posited in Michael ShermerMichael ShermerMichael Brant Shermer is an American science writer, historian of science, founder of The Skeptics Society, and Editor in Chief of its magazine Skeptic, which is largely devoted to investigating pseudoscientific and supernatural claims. The Skeptics Society currently has over 55,000 members...
's "Skeptic" column in the Jan 2002 issue of Scientific American. - Skitt's law – A corollary of Muphry's lawMuphry's lawMuphry's law is an adage that states that "if you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written"...
, variously expressed as, "Any post correcting an error in another post will contain at least one error itself," or, "The likelihood of an error in a post is directly proportional to the embarrassment it will cause the poster." - Smeed's lawSmeed's lawSmeed's Law, named after R. J. Smeed, who first proposed the relationship in 1949, is an empirical rule relating traffic fatalities to traffic congestion as measured by the proxy of motor vehicle registrations and country population. Thus, increasing traffic volume leads to an increase in...
– An empirical rule relating traffic fatalities to traffic congestion as measured by the proxy of motor vehicle registrations and country population. After R. J. Smeed. - Snell's lawSnell's lawIn optics and physics, Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass...
– The simple formula used to calculate the refractionRefractionRefraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
of light when travelling between two media of differing refractive indexRefractive indexIn optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
. It is named after one of its discoverers, DutchNetherlandsThe Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
mathematician Willebrord van Roijen Snell (1580–1626). - Sowa's law of standardsJohn F. SowaJohn Florian Sowa is the computer scientist who invented conceptual graphs, a graphic notation for logic and natural language, based on the structures in semantic networks and on the existential graphs of Charles S. Peirce. He is currently developing high-level "ontologies" for artificial...
– "Whenever a major organization develops a new system as an official standard for X, the primary result is the widespread adoption of some simpler system as a de facto standard for X." - Stang's lawStang's lawStang's law is a Proto-Indo-European phonological rule named after Norwegian linguist Christian Stang. The law governs the word-final sequences of a vowel, followed by a laryngeal or a semivowel */y/ or */w/, followed by a nasal, and according to the law those sequences are simplified in a way that...
– A Proto-Indo-EuropeanProto-Indo-European languageThe Proto-Indo-European language is the reconstructed common ancestor of the Indo-European languages, spoken by the Proto-Indo-Europeans...
phonologicalProto-Indo-European phonologyThe phonology of the Proto-Indo-European language has been reconstructed by linguists, based on the similarities and differences among current and extinct Indo-European languages...
rule named after Norwegian linguist Christian Stang. The law governs the word-final sequences of a vowel, followed by a laryngeal or a semivowel */y/ or */w/, followed by a nasal, and according to the law those sequences are simplified in a way that laryngeals and semivowels are dropped, with compensatory lengtheningCompensatory lengtheningCompensatory lengthening in phonology and historical linguistics is the lengthening of a vowel sound that happens upon the loss of a following consonant, usually in the syllable coda...
of a preceding vowel. - Stefan–Boltzmann law – The total energyEnergyIn physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
radiated per unit surface areaAreaArea is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...
of a black bodyBlack bodyA black body is an idealized physical body that absorbs all incident electromagnetic radiation. Because of this perfect absorptivity at all wavelengths, a black body is also the best possible emitter of thermal radiation, which it radiates incandescently in a characteristic, continuous spectrum...
in unit timeTimeTime is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
is directly proportionalProportionality (mathematics)In mathematics, two variable quantities are proportional if one of them is always the product of the other and a constant quantity, called the coefficient of proportionality or proportionality constant. In other words, are proportional if the ratio \tfrac yx is constant. We also say that one...
to the fourth power of the black body's thermodynamic temperatureThermodynamic temperatureThermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is an "absolute" scale because it is the measure of the fundamental property underlying temperature: its null or zero point, absolute zero, is the...
. Named for Jožef StefanJoseph StefanJoseph Stefan was a physicist, mathematician, and poet of Slovene mother tongue and Austrian citizenship.- Life and work :...
(1835–1893) and Ludwig BoltzmannLudwig BoltzmannLudwig Eduard Boltzmann was an Austrian physicist famous for his founding contributions in the fields of statistical mechanics and statistical thermodynamics...
. - Stein's law – If something cannot go on forever, it will stop. If a trend cannot go on forever, there is no need for action or a program to make it stop, much less to make it stop immediately; it will stop of its own accord.
- Stevens' power lawStevens' power lawStevens' power law is a proposed relationship between the magnitude of a physical stimulus and its perceived intensity or strength. It is often considered to supersede the Weber–Fechner law on the basis that it describes a wider range of sensations, although critics argue that the validity of the...
– In physics, this law relates the intensity of a stimulus to its perceived strength. It supersedes the Weber-Fechner law, since it can describe a wider range of sensations. The theory is named after its inventor, S. Smith Stevens (1906–1973). - Stigler's lawStigler's law of eponymyStigler's law of eponymy is a process proposed by University of Chicago statistics professor Stephen Stigler in his 1980 publication "Stigler’s law of eponymy". In its simplest and strongest form it says: "No scientific discovery is named after its original discoverer." Stigler named the...
– No scientific discovery is named after its original discoverer, named by statistician Stephen StiglerStephen StiglerStephen Mack Stigler is Ernest DeWitt Burton Distinguished Service Professor at the Department of Statistics of the University of Chicago. His research has focused on statistical theory of robust estimators and the history of statistics...
who attributes it to sociologist Robert K. Merton, making the law self-referentialSelf-referenceSelf-reference occurs in natural or formal languages when a sentence or formula refers to itself. The reference may be expressed either directly—through some intermediate sentence or formula—or by means of some encoding...
. - Stokes' lawStokes' lawIn 1851, George Gabriel Stokes derived an expression, now known as Stokes' law, for the frictional force – also called drag force – exerted on spherical objects with very small Reynolds numbers in a continuous viscous fluid...
– An expression for the frictionFrictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
al force exerted on spherical objects with very small Reynolds numbers, named for George Gabriel StokesGeorge Gabriel StokesSir George Gabriel Stokes, 1st Baronet FRS , was an Irish mathematician and physicist, who at Cambridge made important contributions to fluid dynamics , optics, and mathematical physics...
, (1819–1903) - Sturgeon's lawSturgeon's LawSturgeon's revelation, commonly referred to as Sturgeon's law, is an adage derived from quotations by Theodore Sturgeon, an American science fiction author. While Sturgeon coined another adage that he termed "Sturgeon's law", it is his "revelation" that is usually referred to by that term...
– "Ninety percent of everything is crud." Derived from a quote by science fictionScience fictionScience fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
author Theodore SturgeonTheodore SturgeonTheodore Sturgeon was an American science fiction author.His most famous novel is More Than Human .-Biography:...
(1918–1985). - Sutton's lawSutton's lawSutton's law states that when diagnosing, one should first consider the obvious. It suggests that one should first conduct those tests which could confirm the most likely diagnosis...
– "Go where the money is". Often cited in medical schools to teach new doctors to spend resources where they are most likely to pay off. The law is named after bank robber Willie SuttonWillie SuttonWilliam "Willie" Sutton was a prolific U.S. bank robber. During his forty-year criminal career he stole an estimated $2 million, and eventually spent more than half of his adult life in prison...
, who when asked why he robbed banks, is claimed to have answered "Because that's where the money is." - Szemerényi's lawSzemerényi's lawSzemerényi's law is a Proto-Indo-European phonological rule, named after Hungarian linguist Oswald Szemerényi, according to which word-final clusters of vowels , resonants and of either */s/ or */h₂/ are simplified by dropping the word-final fricative , with compensatory lengthening of the...
– A Proto-Indo-EuropeanProto-Indo-European languageThe Proto-Indo-European language is the reconstructed common ancestor of the Indo-European languages, spoken by the Proto-Indo-Europeans...
phonologicalProto-Indo-European phonologyThe phonology of the Proto-Indo-European language has been reconstructed by linguists, based on the similarities and differences among current and extinct Indo-European languages...
rule, named after Hungarian linguist Oswald SzemerényiOswald SzemerényiOswald John Louis Szemerényi was a Hungarian Indo-Europeanist with strong interests in comparative linguistics in general....
, according to which word-final clusters of vowels (V), resonants (R) and of either */s/ or */h₂/ are simplified by dropping the word-final fricative (} was phonetically itself probably a back fricative), with compensatory lengtheningCompensatory lengtheningCompensatory lengthening in phonology and historical linguistics is the lengthening of a vowel sound that happens upon the loss of a following consonant, usually in the syllable coda...
of the preceding vowel.
T–Z
- Thomas theoremThomas theoremThe Thomas theorem is a theory of sociology which was formulated in 1928 by W. I. Thomas :In other words, the interpretation of a situation causes the action. This interpretation is not objective. Actions are affected by subjective perceptions of situations...
– "If men define situations as real, they are real in their consequences," a social law as far as there are any. (After W.I. Thomas and D.S. Thomas.) - Tobler's first law of geography – "Everything is related to everything else, but near things are more related than distant things." Coined by Waldo R. ToblerWaldo R. ToblerWaldo Tobler is an American-Swiss geographer and cartographer. Tobler's idea that "Everything is related to everything else, but near things are more related to each other" is referred to as the "first law of geography." Tobler is a Professor Emeritus at the University of California, Santa Barbara...
(b.1930). - Tully-Fisher relationTully-Fisher relationIn astronomy, the Tully–Fisher relation, published by astronomers R. Brent Tully and J. Richard Fisher in 1977, is an empirical relationship between the intrinsic luminosity of a spiral galaxy and its velocity width...
– Stated by R. Brent TullyR. Brent TullyR. Brent Tully is an astronomer at the Institute for Astronomy in Honolulu, Hawaii.Tully's specialty is astrophysics of galaxies. He, along with J. Richard Fisher, proposed the now-famous Tully-Fisher relation in a paper, A New Method of Determining Distances to Galaxies, published in Astronomy...
and J. Richard FisherJ. Richard FisherJ. Richard Fisher is an astronomer at the National Radio Astronomy Observatory at Charlottesville, VA. He received his Ph.D. in Astronomy from the University of Maryland, College Park and his B.S. in Physics from the Pennsylvania State University.Fisher, along with R...
, relates the intrinsic luminosity of a galaxy to its velocity width. - Verdoorn's lawVerdoorn's LawVerdoorn's law is named after Dutch economist, Petrus Johannes Verdoorn. In economics, this law pertains to the relationship between the growth of output and the growth of productivity. According to the law, faster growth in output increases productivity due to increasing returns...
– In economics, this law pertains to the relationship between the growth of output and the growth of productivity. According to the law, faster growth in output increases productivity due to increasing returns. Named after Dutch economist, Petrus Johannes Verdoorn. - Verner's lawVerner's lawVerner's law, stated by Karl Verner in 1875, describes a historical sound change in the Proto-Germanic language whereby voiceless fricatives *f, *þ, *s, *h, *hʷ, when immediately following an unstressed syllable in the same word, underwent voicing and became respectively the fricatives *b, *d, *z,...
– Stated by Karl VernerKarl VernerKarl Verner was a Danish linguist. He is remembered today for Verner's law, which he discovered in 1875.Verner, whose interest in languages was stimulated by reading about the work of Rasmus Christian Rask, began his university studies in 1864. He studied Oriental, Germanic and Slavic languages,...
in 1875, Verner's law describes a historical sound changeSound changeSound change includes any processes of language change that affect pronunciation or sound system structures...
in the Proto-Germanic languageProto-Germanic languageProto-Germanic , or Common Germanic, as it is sometimes known, is the unattested, reconstructed proto-language of all the Germanic languages, such as modern English, Frisian, Dutch, Afrikaans, German, Luxembourgish, Danish, Norwegian, Icelandic, Faroese, and Swedish.The Proto-Germanic language is...
whereby voiceless fricatives *f, *þ, *s and *x, when immediately following an unstressed syllable in the same word, underwent voicing and became respectively *b, *d, *z and *g. - Wagner's lawWagner's LawWagner's law, also known as the law of increasing state spending, is a principle named after the German economist Adolph Wagner . The law predicts that the development of an industrial economy will be accompanied by an increased share of public expenditure in gross national product:Wagner's law...
predicts that the development of an industrial economy will be accompanied by an increased share of public expenditure in gross national product, and is named after the German economist Adolph WagnerAdolph WagnerAdolph Wagner was a German economist and politician, a leading Kathedersozialist and public finance scholar and advocate of Agrarianism...
(1835–1917). - Weber-Fechner law – This law named after the Germans Ernst Heinrich WeberErnst Heinrich WeberErnst Heinrich Weber was a German physician who is considered one of the founders of experimental psychology.Weber studied medicine at Wittenberg University...
and Gustav Theodor FechnerGustav FechnerGustav Theodor Fechner , was a German experimental psychologist. An early pioneer in experimental psychology and founder of psychophysics, he inspired many 20th century scientists and philosophers...
attempts to describe the human perception of various physical stimuli. In most cases, Stevens' power lawStevens' power lawStevens' power law is a proposed relationship between the magnitude of a physical stimulus and its perceived intensity or strength. It is often considered to supersede the Weber–Fechner law on the basis that it describes a wider range of sensations, although critics argue that the validity of the...
gives a more accurate description. - Wike's law of low odd primesWike's law of low odd primesWike's law of low odd primes is a methodological principle to help design sound experiments in psychology. It is: "If the number of experimental treatments is a low odd prime number, then the experimental design is unbalanced and partially confounded" Wike's law of low odd primes is a...
– "If the number of experimental treatments is a low odd prime number, then the experimental design is unbalanced and partially confounded." (Wike, 1973, pp. 192–193). - Wirth's lawWirth's lawWirth's law is a computing adage made popular by Niklaus Wirth in 1995:Wirth attributed the saying to Martin Reiser, who, in the preface to his book on the Oberon System, wrote: The hope is that the progress in hardware will cure all software ills...
– Software gets slower faster than hardware gets faster. - Wolff's lawWolff's lawWolff's law is a theory developed by the German Anatomist/Surgeon Julius Wolff in the 19th century that states that bone in a healthy person or animal will adapt to the loads it is placed under. If loading on a particular bone increases, the bone will remodel itself over time to become stronger...
– Bone adapts to pressure, or a lack of it. A broken bone is stronger once repaired. - Woodward–Hoffmann rules – in organic chemistry predicting the stereochemistry of pericyclic reactions based on orbital symmetry.
- Zawinski's law – Every program attempts to expand until it can read mail. Those programs which cannot so expand are replaced by ones which can.
- Zipf's law – In linguisticsLinguisticsLinguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
, the observation that the frequency of use of the nth-most-frequently-used word in any natural language is approximately inversely proportional to n, or, more simply, that a few words are used very often, but many or most are used rarely. Named after George Kingsley Zipf (1902–1950), whose statistical body of research led to the observation. More generally, the term Zipf's law refers to the probability distributionProbability distributionIn probability theory, a probability mass, probability density, or probability distribution is a function that describes the probability of a random variable taking certain values....
s involved, which are applied by statisticians not only to linguistics but also to fields remote from that.
See also
- EponymEponymAn eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
- EtymologyEtymologyEtymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...
- List of eponyms
- Lists of etymologies
- List of paradoxes
- List of scientific laws named after people
- Scientific phenomena named after peopleScientific phenomena named after peopleThis is a list of scientific phenomena and concepts named after people . For other lists of eponyms, see eponym.-A:* Abderhalden–Fauser reaction – Emil Abderhalden* Abney effect, Abney's law of additivity – William de Wiveleslie Abney...