List of eponymous laws

This list of eponymous laws provides links to articles on laws, adages, 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 eponymous names despite the absence of the named person.

A

• Amara's law — "We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run".
• Amdahl's law — Used to find out the maximum expected improvement to an overall system when only a part of it is improved. Named after Gene Amdahl (born 1922)
• Ampère's law — In physics, it relates the circulating magnetic field in a closed loop to the electric current passing through the loop. Discovered by André-Marie Ampère.
• Archie's law — In petrophysics, relates the in-situ electrical conductivity of sedimentary rock to its porosity and brine saturation. Named for Gus Archie (1907 – 1978)
• Asimov's three laws of robotics — also called, more simply, the Three Rules of Robotics, a set of rules which the fictional robots appearing in the writings of Isaac Asimov (1920–1992) must obey.
• Avogadro's law — In chemistry and physics, one of the gas laws, relating to the volume and molarity of a gas.

B–D

• Bechdel's Law — A movie is only worth watching if it contains 1) at least two women, 2) who talk to each other, 3) about something other than a man.
• Beer-Lambert law — in optics, the empirical relationship of the absorption of light to the properties of the material the light is travelling through. Independently discovered (in various forms) by Pierre Bouguer in 1729, Johann Heinrich Lambert in 1760 and August Beer in 1852.
• Benford's law — 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 field set up by a steady current density. Named for Jean-Baptiste Biot and Félix Savart.
• Boyle's law — In physics, one of the gas laws, relating the volume and pressure of an ideal gas held at a constant temperature. Discovered by and named after Robert Boyle (1627–1691)
• Bradford's law — a pattern described by Samuel C. Bradford in 1934 that estimates the exponentially diminishing returns of extending a library search
• Brooks' law — Adding manpower to a late software project makes it later. Named after Fred Brooks, author of the well known tome on Project Management, The Mythical Man-Month.
• Brim-DeForest's law — Life is a self-correcting system. Named after Brady Brim-DeForest, expedition philosopher and director for 'The Travels of Ibn Battuta.'
• Buys Ballot's law is 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 validation of an existing theory, in 1857.
• Bye's First Law of Model Railroading - Anytime you wish to demonstrate something, the number of faults is proportional to the number of viewers.
• Callahan's Principle — You can't argue with stupid. A corollary to Hanlon's razor and Finagle's law, normally taking the form "Never attribute to malice that which can be adequately explained by stupidity."
• Charles's law 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 Charles.
• Clarke's three laws. Formulated by Arthur C. Clarke. Several corollaries to these laws 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.
• Conway's Law: Any piece of software reflects the organizational structure that produced it. Named for Melvin Conway
• Cooper's law: The number of radio frequency conversations which can be concurrently conducted in a given area doubles every 30 months.
• Coulomb's law is an inverse-square law indicating the magnitude and direction of electrostatic force that one stationary, electrically charged object of small dimensions (ideally, a point source) exerts on another. It is named after Charles-Augustin de Coulomb.
• Dale's principle: In neuroscience, states that a neuron is capable of producing and secreting only one neurotransmitter from its axon terminals. Named after Henry Hallett Dale but more recent data suggests it to be false.
• Dalton's law — In chemistry and physics, 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. Also called Dalton's law of partial pressure, and related to the ideal gas laws, this empirical law was observed by John Dalton in 1801.
• De Morgan's laws — apply to formal logic regarding the negation of pairs of logical operators.
• Dermott's Law — the sidereal period of major satellites tends to follow a geometric series. Named after Stanley Dermott.
• Dilbert Principle — Coined by Scott Adams as a variation of the Peter Principle of employee advancement. Named after Adams' Dilbert 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 Law — "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.
• Duverger's law — 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

• Ebert's law — Roger Ebert's oft-quoted and essential rule of thumb when reviewing a film: "It's not what the movie is about, it's how it's about it."
• Edwards' law — "You cannot apply a technological solution to a sociological problem."
• Faraday's law of induction states that a magnetic field changing in time creates a proportional electromotive force. Named for Michael Faraday, based on his work in 1831
• Faraday's law of electrolysis states that the mass of a substance produced at an electrode during electrolysis is proportional to the number of moles of electrons transferred at that electrode; again named for Michael Faraday.
• Fick's laws of diffusion describe diffusion, and define the diffusion coefficient D, and were derived by Adolf Fick in the year 1855.
• Finagle's law — Generalized version of Murphy's law, fully named Finagle's Law of Dynamic Negatives and usually rendered "anything that can go wrong, will". Not strictly eponymous, since there was no Finagle.
• Fitts's law — A principle of human movement published in 1954 by Paul Fitts 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 computer, 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 proportional to the gradient of temperature difference; named for Joseph Fourier.
• Gall's law — "A complex system that works is invariably found to have evolved from a simple system that worked."
• Gauss's law — In physics, gives the relation between the electric flux flowing out a closed surface and the charge enclosed in the surface. It was formulated by Carl Friedrich Gauss.
• Godwin's Law — An adage in Internet culture that states "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one." Coined by Mike Godwin in 1990.
• Goodhart's law — When a measure becomes a target, it ceases to be a good measure.
• Graham's law — In physics, a gas law which states that the average kinetic energy of the molecules of two samples of different gases at the same temperature is identical. It is named for Thomas Graham (1805–1869), who formulated it.
• Greenspun's Tenth Rule — 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 Greenspun.
• Gresham's law — "bad money drives good money out of circulation". Coined in 1858 by British economist Henry Dunning Macleod, and named for Sir Thomas Gresham (1519–1579). The principle had been stated before Gresham by others, including Nicolaus Copernicus.
• Grimm's law — explains correspondence between some consonants in Germanic languages vs. other Indo-European languages. Discovered by Jacob Grimm, (1785 – 1863), German philologist and mythologist and one of the Brothers Grimm.
• Gustafson's Law (also known as Gustafson-Barsis' law) is a law in computer engineering which states that any sufficiently large problem can be efficiently parallelized. Coined by John Gustafson in 1988

H–K

• Hanlon's razor — A corollary of Finagle's law, normally taking the form "Never attribute to malice that which can be adequately explained by stupidity.". As with Finagle, possibly not strictly eponymous. Alternately, "Do not invoke conspiracy as explanation when ignorance and incompetence will suffice, as conspiracy implies intelligence."
• Heisenberg's Uncertainty principle — 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 the position and momentum.
• Hebb's law states that "Neurons that fire together wire together."
• Henry's law — The mass of a gas that dissolves in a definite volume of liquid is directly proportional to the pressure of the gas provided the gas does not react with the solvent.
• Herblock's law states that "If it's good, they'll stop making it." Possibly coined by Herbert Lawrence Block, whose pen name was Herblock.
• Hofstadter's law — "It always takes longer than you expect, even when you take into account Hofstadter's Law." It was created by Douglas Hofstadter in his book Gödel, Escher, Bach.
• Hooke's law — The tension on a spring or other elastic object is proportional to the displacement from the equilibrium. Named after Robert Hooke (1635–1703)
• Hotelling's law in economics — Under some conditions, it is rational for competitors to make their products as nearly identical as possible.
• Hubble's law — Galaxies recede from an observer at a rate proportional to their distance to that observer. Formulated by Edwin Hubble in 1929.
• Hutber's law — "Improvement means deterioration". Coined by financial journalist Patrick Hutber.
• Hume's Law — In meta-ethics, the assertion that normative statements cannot be deduced exclusively from descriptive statements.
• Isaac Bonewits laws of magic - "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 Bonewits.
• Kepler's laws of planetary motion — govern the motion of the planets around the sun, and were first discovered by Johannes Kepler
• Kerckhoffs' law on secure cryptography by Auguste Kerckhoffs a cryptosystem should be secure even if everything about the system, except the key, is public knowledge
• Keynes' Law — Demand creates its own supply
• Kirchhoff's laws — one law in thermodynamics and two about electrical circuits, named after Gustav Kirchhoff.

L–M

• Leibniz's law — a principle in metaphysics 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.
• Linus's law — named for Linus Torvalds, states "given enough eyeballs, all bugs are shallow". This law is, incidentally, the only one on this list to use the forename rather than the family name.
• Little's law, in queueing theory, says 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 law — States that individuals can expect miracles to happen to them, at the rate of about one per month. Coined by Professor J E Littlewood, (1885–1977)
• Macfarlane's law — You can talk faster than you can type, but you can read faster than you can listen. [late 1970s]
• Meadow's law is a precept, now discredited, that since cot deaths are so rare, "One is a tragedy, two is suspicious and three is murder, until proved otherwise." It was named for Sir Roy Meadow, a discredited paediatrician prominent in the United Kingdom in the last quarter of the twentieth century.
• Metcalfe's law — In communications and network theory, states that the value of a system grows as approximately the square of the number of users of the system. Framed by Robert Metcalfe in the context of the ethernet.
• Moore's law — An empirical observation stating that the complexity of integrated circuits doubles every 24 months. Outlined in 1965 by Gordon Moore, co-founder of Intel
• Moynihan's law — "The amount of violations of human rights in a country is always an inverse function of the amount of complaints about human rights violations heard from there. The greater the number of complaints being aired, the better protected are human rights in that country." Coined by Daniel Patrick Moynihan (1927–2003).
• Muphry's law - "if you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written", first described by Australian editor John Bangsund in 1992. Name derived from Murphy's law.
• Murphy's law — Most commonly formulated as "if anything can go wrong, it will", less commonly "If it can happen, it will happen". Ascribed to Edward A. Murphy, Jr.

N–Q

• Newton's laws of motion — In physics, three scientific laws concerning the behaviour of moving bodies, which are fundamental to classical mechanics (and since Einstein, which are valid only within inertial reference frames). Discovered and stated by Isaac Newton (1643– 1727).
  • First law: A body remains at rest, or moves 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 force acting upon it.
  • Third law: Whenever one body exerts force upon a second body, the second body exerts an equal and opposite force upon the first body.
• 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.
• Occam's razor — States that explanations should never multiply causes without necessity. When two explanations are offered for a phenomenon, the simplest full explanation is preferable. Named after William of Ockham (ca.1285–1349)
• Ohm's law — In physics, states that the ratio of the potential difference (or voltage drop) between the ends of a conductor (and resistor) to the current flowing through it is a constant, provided the temperature doesn't change. Discovered and named after Georg Simon Ohm (1789–1854).
• Parkinson's law — "Work expands so as to fill the time available for its completion". Coined by C. Northcote Parkinson (1909–1993)
• Pareto principle — States that for many phenomena 80% of consequences stem from 20% of the causes. Named after Italian economist Vilfredo Pareto, but framed by management thinker Joseph M. Juran.
• Peckham's Law - Beauty times brains equals a constant.
• Peter principle — "In a hierarchy, every employee tends to rise to his level of incompetence". Coined by Laurence J. Peter (1919–1990)
• Poe's Law — Without a winking smiley or other blatant display of humor, it is impossible to create a parody of Fundamentalism that someone won't mistake for the real thing.
• 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").

R–T

• Raoult's law — In chemistry, Raoult's law states that the vapor pressure of mixed liquids is dependent on the vapor pressures of the individual liquids and the molar vulgar fraction of each present in solution.
• Reed'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.
• Reilly's law — of Retail Gravitation, people generally patronize the largest mall in the area.
• Roemer's law — a hospital bed built is a bed filled
• Rothbard's law — everyone specializes in his own area of weakness.
• Salem hypothesis — the conjecture that an education in the engineering disciplines forms a predisposition to Scientific Creationism
• Sarnoff's law — the value of a broadcast network is proportional to the number of viewers.
• Say's law — attributed to economist Jean-Baptiste Say and contrasted to Keynes' law (discussed above), saying that "supply creates its own demand," i.e., that 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 glut[1].
• Sayre's law — "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 Law - "Any person can invent a security system so clever that she or he can't think of how to break it."
• Segal's law — "A man with a watch knows what time it is. A man with two watches is never sure."
• Shenker's law -- "Whatever subfield of theoretical physics you feel is the most worthless, that is the one which will be the source of the next breakthrough." Due to Stephen Shenker, a string theorist at Stanford.
• Skitt's law — a corollary of Muphry's law, 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."
• Snell's law is the simple formula used to calculate the refraction of light when traveling between two media of differing refractive index. It is named after one of its discoverers, Dutch mathematician Willebrord van Roijen Snell (1580–1626).
• Sod's law — Another name for Murphy's law.
• Stang's law — 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 laryngeals and semivowels are dropped, with compensatory lengthening of a preceding vowel.
• Stein's law — An observation regarding sustainability: "If something cannot go on forever, it will stop." Herbert Stein
• Stevens' power law — 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 law — No scientific discovery is named after its original discoverer, named by statistician Stephen Stigler who attributes it to sociologist Robert K. Merton, making the law self-referential.
• Stokes' law — an expression for the frictional force exerted on spherical objects with very small Reynolds numbers, named for George Gabriel Stokes, (1819–1903)
• Sturgeon's law — "Nothing is always absolutely so." Derived from a quote by science fiction author Theodore Sturgeon (1918–1985)
• Sturgeon's revelation — "90 percent of everything is crap."
• Sutton's law — "'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 Sutton, who when asked why he robbed banks is claimed to have answered "Because that's where the money is."
• Szemerényi's law — a Proto-Indo-European phonological rule, named after Hungarian linguist Oswald Szemerényi, 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 (*/h₂/ was phonetically itself probably a back fricative), with compensatory lengthening of the preceding vowel.

U–Z

• Verdoorn's Law — named after Dutch economist, Jake 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.
• Verner's law — Stated by Karl Verner in 1875, Verner's law describes a historical sound change in the Proto-Germanic language 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.
• Weber-Fechner law — This law named after Ernst Heinrich Weber and Gustav Theodor Fechner attempts to describe the human perception of various physical stimuli. In most cases, Stevens' power law gives a more accurate description.
• Wirth's law — Software gets slower faster than hardware gets faster.
• 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 linguistics, 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 work research led to the observation. More generally, the term Zipf's law refers to the probability distributions involved, which are applied by statisticians not only to linguistics but also to fields remote from that.

See also

• Eponym
• Etymology
• List of eponyms
• Lists of etymologies
• List of paradoxes
• Scientific laws named after people
• Scientific phenomena named after people