This list of eponymous laws provides links to articles on laws, principles, 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. Named laws range from significant scientific laws such as Newton's laws of motion, to humorous examples such as Murphy's law.
A–B
Acton's dictum: "Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men [...]" Aitken's law describes how vowel length in Scots and Scottish English is conditioned by environment. Named for Professor A. J. Aitken, who formulated it. Alder's razor: See Newton's flaming laser sword below. Allen's rule: Endotherms from colder climates usually have shorter limbs (or appendages) than the equivalent animals from warmer climates. Amagat's law describes the behaviour and properties of mixtures of ideal gases. Named for Émile Amagat. Amara's law: "We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run." Named after Roy Amara (1925–2007). Amdahl's law is used to find out the maximum expected improvement to an overall system when only a part of it is improved. Named after Gene Amdahl (1922–2015). Ampère's circuital law, in physics, relates the circulating magnetic field in a closed loop to the electric current through the loop. Discovered by André-Marie Ampère. Ampère's force law, in physics, relates the mutual force between two parallel electrical conductors to the electric current flowing through them, and their separation distance. Anderson's rule is used for the construction of energy band diagrams of the heterojunction between two semiconductor materials. Named for R. L. Anderson. Anderson's rule (computer science) refers to a trilemma of security, functionality, and scale, of systems that handle sensitive personal information. Named for Ross J. Anderson. Andy and Bill's law describes how, when a computer chip is released, new software will be released to use up all of its power. Named for Andy Grove, then CEO of Intel, and Bill Gates, then CEO of Microsoft. 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). Archimedes' lever: "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world". Archimedes' principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces. Named for Archimedes. Artin reciprocity law is a general theorem in number theory that forms a central part of global class field theory. Named after Emil Artin. Ashby's law of requisite variety, that the number of states in a control mechanism must be greater than or equal to the number of states in the system it controls. Asimov's Three Laws of Robotics formulated by Isaac Asimov: A robot may not injure a human being or, through inaction, allow a human being to come to harm. A robot must obey the orders given it by human beings, except where such orders would conflict with the First Law. A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws. (Asimov later added what became known as the "Zeroth Law", to precede the initial three: A robot may not harm humanity, or, by inaction, allow humanity to come to harm.) Atwood's law: Any software that can be written in JavaScript will eventually be written in JavaScript. Augustine's laws on air force management. 52 humorous laws formulated by Norman R. Augustine. Avogadro's law, one of the gas laws, states that: "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules." Babinet's principle, in physics, states that the diffraction pattern from an opaque body is identical to that from a hole of the same size and shape except for the overall forward beam intensity. Named for Jacques Babinet. Baldwin's rules predict feasibility of ring-closing reactions in organic synthesis, proposed by Jack Baldwin. Barlow's law was an incorrect physical law proposed by Peter Barlow in 1825 to describe the ability of wires to conduct electricity. Bayes' theorem describes the probability of an event, based on prior knowledge of conditions that might be related to the event. Bechdel test, AKA Bechdel–Wallace test, measures representation of women in film and other fiction by asking if a work features at least two women who have a conversation about something other than a man. Named for Alison Bechdel. Beckstrom's law, in economics, states that the value of a network equals the net value added to each user's transactions conducted through that network, summed over all users. Named for Rod Beckstrom. Bedrosian's theorem in signal processing: the Hilbert transform of the product of a low-pass and a high-pass signal with non-overlapping spectra is given by the product of the low-pass signal and the Hilbert transform of the high-pass signal. Beer–Lambert law: in optics, the empirical relationship of the absorption of light to the properties of the material through which the light is traveling. Independently discovered (in various forms) by Pierre Bouguer in 1729, Johann Heinrich Lambert in 1760 and August Beer in 1852. Benford's law: In many collections of data, a given data point has roughly a 30% chance of starting with the digit 1. Benford's law of controversy: Passion is inversely proportional to the amount of real information available. Bennett's laws are principles in quantum information theory. Named for Charles H. Bennett. Bergmann's rule: within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, and species of smaller size are found in warmer regions. Bernoulli's principle, in fluid dynamics, describes the effect that flow has on pressure contributing lift to airfoils. Betteridge's law of headlines: "any headline which ends in a question mark can be answered by the word 'no. Betz's law: No wind turbine can capture more than 16/27 (59.3%) of the kinetic energy in wind, independent of the design of the turbine, in open flow. Biot–Savart law describes the magnetic field set up by a steady current density. Named for Jean-Baptiste Biot and Félix Savart. Birch's law, in geophysics, establishes a linear relation of the compressional wave velocity of rocks and minerals of a constant average atomic weight. Named after Francis Birch. Bloch's law: in human vision, the product of contrast and luminosity is a constant for small targets below the resolution limit. Bode's law, another name for the Titius–Bode law. Born's law, in quantum mechanics, gives the probability that a measurement on a quantum system will yield a given result. Named after physicist Max Born. Boyle's law, in physics, one of the gas laws, states that the volume and pressure of an ideal gas of fixed mass held at a constant temperature are inversely proportional, or, that the product of absolute pressure and volume of a fixed mass is always constant. Discovered by and named after Robert Boyle (1627–1691). Bradford's law is a pattern described by Samuel C. Bradford in 1934 that estimates the exponentially diminishing returns of extending a library search. Bragg's law, in physics, gives the angles for coherent and incoherent scattering from a crystal lattice. Brandolini's law: The amount of energy needed to refute bullshit is an order of magnitude bigger than to produce it. Named after Italian programmer Alberto Brandolini. Brewster's law, an angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection. Named after Scottish physicist David Brewster. Briffault's law: "The female, not the male, determines all the conditions of the animal family. Where the female can derive no benefit from association with the male, no such association takes place." Named after Robert Briffault. Brooks's law: "Adding manpower to a late software project makes it later." Named after Fred Brooks, author of the well known book on project management The Mythical Man-Month. 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. Byerlee's law gives the stress circumstances in the Earth's crust at which fracturing along a geological fault takes place.
C–D
Campbell's law: "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 after Donald T. Campbell (1916–1996). Casper's Dictum is a law in forensic medicine that states the ratio of time a body takes to putrefy in different substances – 1:2:8 in air, water and earth. Cassie's law describes the effective contact angle θc for a liquid on a composite surface. Cassini's laws provide a compact description of the motion of the Moon. Established in 1693 by Giovanni Domenico Cassini. 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! Trilogy. Chargaff's rules state that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. Discovered by Austrian chemist Erwin Chargaff. Charles's law, one of the gas laws in physics, 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 kelvin) increases or decreases. Named after Jacques Charles. Chekhov's gun states that nonessential elements of a story must be removed. Cheops law: Nothing ever gets built on schedule or within budget. Chesterton's fence states that reforms should not be made until the reasoning behind the existing state of affairs is understood. Child's law states that the space-charge limited current in a plane-parallel diode varies directly as the three-halves power of the anode voltage and inversely as the square of the distance separating the cathode and the anode. Named after Clement D. Child; also known as the Child–Langmuir law (after Irving Langmuir). See also Mott–Gurney law. Chladni's law relates the frequency of modes of vibration for flat circular surfaces with fixed center as a function of the numbers of diametric (linear) nodes and of radial (circular) nodes. Named after Ernst Chladni. Claasen's law, or the logarithmic law of usefulness: usefulness = log(technology). 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.