A

• Accelerator effect
  Accelerator effect
  The accelerator effect in economics refers to a positive effect on private fixed investment of the growth of the market economy . Rising GNP implies that businesses in general see rising profits, increased sales and cash flow, and greater use of existing capacity...
  
   (economics)
• Accordion effect
  Accordion effect
  In non-linear physics, the accordion effect occurs when fluctuations in the motion of a travelling body causes disruptions in the flow of elements following it. This can happen in road traffic, foot marching, bicycle racing, and, in general, to processes in a pipeline...
  
   (physics) (waves)
• Acousto-optic effect (nonlinear optics) (waves)
• Additive genetic effects
  Additive genetic effects
  The additive genetic effect is an estimate of the quantitative change in a trait that is associated with substituting one allele with that of another allele within an interbreeding population. Additive effects are often calculated by genotyping and phenotyping offspring of a genetic test cross...
  
   (genetics)
• Aharonov–Bohm effect (quantum mechanics)
• Alienation effect
  Alienation effect
  The distancing effect, commonly mistranslated as the alienation effect , is a performing arts concept coined by playwright Bertolt Brecht "which prevents the audience from losing itself passively and completely in the character created by the actor, and which consequently leads the audience to be a...
  
   (acting techniques) (Bertolt Brecht theories and techniques) (film theory) (metafictional techniques) (theatre)
• Allais effect
  Allais effect
  The Allais effect is a claimed anomalous precession of the plane of oscillation of a pendulum during a solar eclipse. It has been speculated to be unexplained by standard physical models of gravitation, but recent mainstream physics publications tend rather to posit conventional explanations for...
  
   (fringe physics)
• Allee effect
  Allee effect
  The Allee effect is a phenomenon in biology characterized by a positive correlation between population density and the per capita population growth rate in very small populations.-Description:...
  
   (biology)
• Ambiguity effect
  Ambiguity effect
  The ambiguity effect is a cognitive bias where decision making is affected by a lack of information, or "ambiguity". The effect implies that people tend to select options for which the probability of a favorable outcome is known, over an option for which the probability of a favorable outcome is...
  
   (cognitive biases)
• Anrep effect
  Anrep effect
  The Anrep effect is an autoregulation method in which myocardial contractility increases with afterload. It was experimentally determined that increasing afterload caused a proportional linear increase in ventricular inotropy....
  
   (cardiology) (medicine)
• Antenna effect
  Antenna effect
  The antenna effect, more formally plasma induced gate oxide damage, is an effect that can potentially cause yield and reliability problems during the manufacture of MOS integrated circuits. Fabs normally supply antenna rules, which are rules that must be obeyed to avoid this problem. A violation...
  
   (digital electronics) (electronic design automation)
• Anti-greenhouse effect
  Anti-Greenhouse Effect
  The anti-greenhouse effect is a neologism used to describe two different effects that describe a cooling effect an atmosphere has on the ambient temperature of the planet. Unlike the greenhouse effect, which is common, an anti-greenhouse effect is only known to exist in one situation in our Solar...
  
   (atmospheric dynamics) (atmospheric science) (astronomy) (planetary atmospheres)
• Askaryan effect
  Askaryan effect
  The Askaryan effect is the phenomenon whereby a particle traveling faster than the phase velocity of light in a dense dielectric produces a shower of secondary charged particles which contain a charge anisotropy and thus emits a cone of coherent radiation in the radio or microwave part of the...
  
   (particle physics)
• Asymmetric blade effect
• Audience effect
  Audience effect
  The audience effect is the impact that a passive audience has on a subject performing a task. It was first formally noted in various psychology studies in the early 20th century...
  
   (psychology) (social psychology)
• Auger effect (atomic physics) (foundational quantum physics)
• Aureole effect
  Aureole effect
  The aureole effect or water aureole is an optical phenomenon similar to Heiligenschein, creating sparkling light and dark rays radiating from the shadow of the viewer's head. This effect is seen only over a rippling water surface. The waves act as lenses to focus and defocus sunlight: focused...
  
   (atmospheric optical phenomena) (scientific terminology)
• Autler–Townes effect (atomic, molecular, and optical physics) (atomic physics) (quantum optics)
• Autokinetic effect
  Autokinetic effect
  The autokinetic effect is a phenomenon of human visual perception in which a stationary, small point of light in an otherwise dark or featureless environment appears to move. It was first recorded by a Russian officer keeping watch who observed illusory movement of a star near the horizon...
  
   (vision)
• Avalanche effect
  Avalanche effect
  In cryptography, the avalanche effect refers to a desirable property of cryptographic algorithms, typically block ciphers and cryptographic hash functions. The avalanche effect is evident if, when an input is changed slightly the output changes significantly...
  
   (cryptography)
• Averch–Johnson effect (economics)

B

• Balassa–Samuelson effect (economics)
• Baldwin effect
  Baldwin effect
  The Baldwin effect, also known as Baldwinian evolution or ontogenic evolution, is a theory of a possible evolutionary processes that was originally put forward in 1896 in a paper, "A New Factor in Evolution," by American psychologist James Mark Baldwin. The paper proposed a mechanism for specific...
  
   (evolutionary biology) (selection)
• Balloon-carried light effect
  Balloon-carried light effect
  A balloon-carried light effect is a special effect carried by a balloon, which can be fixed with a rope to the ground or free-flying.-Uses:...
  
   (balloons) (culture) (entertainment)
• Bambi effect
  Bambi Effect
  "The Bambi effect" is a term used anecdotally or in editorial media that refers to objections against the killing of animals that are perceived as "cute" or "adorable", such as deer or dolphins, while there may be little or no objection to the suffering of organisms that are perceived as somehow...
  
   (hunting) (psychology stubs)
• Bandwagon effect
  Bandwagon effect
  The bandwagon effect is a well documented form of groupthink in behavioral science and has many applications. The general rule is that conduct or beliefs spread among people, as fads and trends clearly do, with "the probability of any individual adopting it increasing with the proportion who have...
  
   (cognitive biases) (crowd psychology) (economics effects) (metaphors) (propaganda techniques)
• Bank effect
  Bank effect
  Bank effect refers to the tendency of the stern of a ship to swing toward the near bank when operating in a river or constricted waterway.The asymmetric flow around a ship induced by the vicinity of banks causes pressure differences between port and starboard sides...
  
   (marine propulsion) (nautical terms) (water)
• Barkhausen effect
  Barkhausen effect
  The Barkhausen effect is a name given to the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed...
  
   (condensed matter) (magnetism)
• Barnett effect
  Barnett Effect
  The Barnett effect is the magnetization of an uncharged body when spun on its axis. It was discovered by American physicist Samuel Barnett in 1915....
  
   (condensed matter) (magnetism)
• Baskerville effect
  Baskerville effect
  The Baskerville effect, or the Hound of the Baskervilles effect is a statistical observation that mortality through heart attacks is increased by psychological stress...
  
   (cardiology)
• Bauschinger effect
  Bauschinger effect
  The Bauschinger effect refers to a property of materials where the material's stress/strain characteristics change as a result of the microscopic stress distribution of the material...
  
   (classical mechanics) (materials science)
• Beaujolais effect
  Beaujolais effect
  Beaujolais effect is the name given to a class of potential semantic errors in Jean Ichbiah's draft specifications for the programming language Ada. The name arose from Ichbiah's promise to give a bottle of Beaujolais nouveau red wine to anyone who could find such a situation in the draft language...
  
   (Ada programming language)
• Ben Franklin effect
  Ben Franklin effect
  The Ben Franklin effect is a psychological finding: A person who has done someone a favor is more likely to do that person another favor than they would be if they had received a favor from that person...
  
   (emotion) (psychology)
• Bernoulli effect (equations) (fluid dynamics) (wind power)
• Beta-silicon effect
  Beta-silicon effect
  The beta-silicon effect also called silicon hyperconjugation in organosilicon chemistry is a special type of hyperconjugation and describes the stabilizing effect of a silicon atom placed in a position one removed from a carbocation. A prerequisite is an antiperiplanar relationship between the two...
  
   (physical organic chemistry)
• Bezold effect
  Bezold Effect
  The Bezold effect is an optical illusion, named after a German professor of meteorology, Wilhelm von Bezold , who discovered that a color may appear different depending on its relation to adjacent colors....
  
   (optical illusions) (psychological theories)
• Bezold–Brücke effect (optical illusions)
• Biefeld–Brown effect
  Biefeld–Brown effect
  The Biefeld–Brown effect is an electrical effect that produces an ionic wind that transfers its momentum to surrounding neutral particles, first discovered by Paul Alfred Biefeld and Thomas Townsend Brown . The effect is more widely referred to as electrohydrodynamics or sometimes...
  
   (physical phenomena) (propulsion)
• Big-fish–little-pond effect (educational psychology)( (pedagogy)
• Birthday number effect (psychology)
• Black drop effect
  Black drop effect
  The black drop effect is an optical phenomenon visible during a transit of Venus and, to a lesser extent, a transit of Mercury.Just after second contact, and again just before third contact during the transit, a small black "teardrop" appears to connect Venus' disk to the limb of the Sun, making it...
  
   (astronomical transits)
• Blazhko effect
  Blazhko Effect
  The Blazhko effect, which is sometimes called long-period modulation, is a variation in period and amplitude in RR Lyrae type variable stars. It was first observed by Sergey Blazhko in 1907 in the star RW Dra....
  
   (astronomy)
• Blocking effect
  Blocking effect
  Kamin's blocking effect demonstrates that conditioning to a stimulus could be blocked if the stimulus were reinforced in compound with a previously conditioned stimulus....
  
   (psychology)
• Bloom (shader effect)
  Bloom (shader effect)
  Bloom is a computer graphics effect used in computer games, demos and high dynamic range rendering to reproduce an imaging artifact of real-world cameras. The effect produces fringes of light around very bright objects in an image, obscuring fine details...
  
   (3D computer graphics) (demo effects)
• Bohr effect
  Bohr effect
  Bohr effect is a property of hemoglobin first described in 1904 by the Danish physiologist Christian Bohr , which states that an increasing concentration of protons and/or carbon dioxide will reduce the oxygen affinity of hemoglobin...
  
   (protein)
• Boomerang effect
  Boomerang effect
  In social psychology, the boomerang effect is "the theory of psychological reactance that is supported by experiments showing that attempts to restrict a person's freedom often produce an anticonformity "boomerang effect".-Environmentalism:The term "boomerang effect" can be used to describe the...
  
   (economics and finance)
• Bowditch effect
  Bowditch effect
  The Bowditch Effect is an autoregulation method by which myocardial contractility increases with an increase in heart rate. Also known as the Treppe phenomenon or Treppe effect....
  
   (medicine)
• Bradley effect
  Bradley effect
  The Bradley effect, less commonly called the Wilder effect, is a theory proposed to explain observed discrepancies between voter opinion polls and election outcomes in some United States government elections where a white candidate and a non-white candidate run against each other...
  
   (American political terms) (elections in the United States) (political history of the United States) (political neologisms) (politics and race) (polling) (psephology) (racism)
• Bridgman effect
  Bridgman effect
  The Bridgman effect , also called the internal Peltier effect, is a phenomenon that occurs when an electric current passes through an anisotropic crystal - there is an absorption or liberation of heat because of the non-uniformity in current distribution....
  
   (electricity) (electromagnetism)
• Brookings effect
  Brookings effect
  The Brookings effect, also known as the Chetco effect, is a weather pattern that occasionally occurs along the southern Oregon Coast in the United States...
  
   (atmospheric science) (Curry County, Oregon) (Oregon coast) (Oregon geography) (winds)
• Brown Willy effect
  Brown Willy effect
  The Brown Willy effect is a meteorological phenomenon that sometimes occurs across the south-west peninsula of Britain. It leads to heavy showers developing over the high ground of Bodmin Moor in Cornwall, which then often travel a considerable distance downwind of their place of origin. It is...
  
   (geography of Cornwall) (mesoscale meteorology)
• Bruce effect
  Bruce effect
  The Bruce effect, or pregnancy block, refers to the tendency for female rodents to terminate their pregnancies following exposure to the scent of an unfamiliar male. The effect has primarily been studied in laboratory mice , but is also observed in deer-mice, meadow voles, and collared lemmings...
  
   (reproduction)
• Bullwhip effect
  Bullwhip effect
  The Bullwhip Effect is an observed phenomenon in forecast-driven distribution channels. It refers to a trend of larger and larger swings in inventory in response to changes in demand, as one looks at firms further back in the supply chain for a product...
  
   (distribution, retailing, and wholesaling)
• Butterfly effect
  Butterfly effect
  In chaos theory, the butterfly effect is the sensitive dependence on initial conditions; where a small change at one place in a nonlinear system can result in large differences to a later state...
  
   (chaos theory) (physical phenomena) (stability theory)
• Bystander effect
  Bystander effect
  The bystander effect or Genovese syndrome is a social psychological phenomenon that refers to cases where individuals do not offer any means of help in an emergency situation to the victim when other people are present...
  
  

C

• Cage effect (chemistry)
  Cage effect (chemistry)
  The cage effect in chemistry describes how properties of a molecule are affected by its surroundings.In a solvent a molecule is often more accurately described existing in a cage of solvent molecules, the so-called solvent cage. Reactions occur when a molecule occasionally "jumps out" and meets...
  
  
• Calendar effect
  Calendar effect
  A calendar effect is any economic effect, particularly in markets, which appears to be related to the calendar. Such effects include the apparently different behaviour of stock markets on different days of the week, different times of the month, and different times of year...
  
   (behavioral finance) (economics and finance) (market trends)
• Callendar effect (atmospheric science) (climate) (climate change)
• Captodative effect
  Captodative effect
  The captodative effect in chemistry is the effect on the stability of a carbon-centred radical determined by the combined action of a captor and a dative substituent, both attached to the radical centre...
  
   (organic chemistry)
• Capture effect
  Capture effect
  In telecommunication, the capture effect, or FM capture effect, is a phenomenon associated with FM reception in which only the stronger of two signals at, or near, the same frequency will be demodulated....
  
   (broadcast engineering) (radio) (radio communications/) (telecommunications) (wireless communications)
• Carnoustie effect
  Carnoustie effect
  Carnoustie effect is a term arising after the 1999 Open Golf Championship at Carnoustie, Scotland, when the world's greatest players failed to play to theoretical par for the distance...
  
   (golf) (golf terminology)
• Carryover effect
  Carryover effect
  The carryover effect occurs when two experimental conditions are applied to the same sample or participant, and the effect of the first condition "carries over" to the second. Examples include the effect of practice or fatigue in experimental subjects....
  
   (cooking techniques) (food and drink)
• Cascade effect (ecology)
  Cascade effect (ecology)
  An ecological cascade effect is a series of secondary extinctions that is triggered by the primary extinction of a key species in an ecosystem. Secondary extinctions are likely to occur when the threatened species are: dependent on a few specific food sources, mutualistic, or forced to coexist...
  
  
• Cascade effect
  Cascade effect
  A Cascade Effect is an unforeseen chain of events due to an act affecting a system. If there is a possibility that the cascade effect will have a negative impact on the system, it is possible to analyze the effects with a consequence/impact analysis...
  
   (spaceflight)
• Casimir effect
  Casimir effect
  In quantum field theory, the Casimir effect and the Casimir–Polder force are physical forces arising from a quantized field. The typical example is of two uncharged metallic plates in a vacuum, like capacitors placed a few micrometers apart, without any external electromagnetic field...
  
   (quantum field theory) (physical phenomena)
• Castle thunder (sound effect)
  Castle thunder (sound effect)
  Castle thunder is a sound effect that consists of the sound of a loud thunderclap during a rainstorm. It was originally recorded for the 1931 film Frankenstein, and has since been used in dozens of movies, Disney and Hanna-Barbera cartoons, and TV series, and television commercials...
  
   (in-jokes) (sound effects)
• Catapult effect
  Catapult effect
  In electromagnetics, the catapult effect is a phenomenon occurring when a current is passed through two wires connected by a loose wire in a magnetic field. The loose wire is then catapulted horizontally away from the magnetic field...
  
   (electromagnetism)
• Catch-up effect
  Catch-up effect
  The idea of convergence in economics is the hypothesis that poorer economies' per capita incomes will tend to grow at faster rates than richer economies. As a result, all economies should eventually converge in terms of per capita income...
  
   (economics effects)
• Catfish effect
  Catfish effect
  The catfish effect is the effect that a strong competitor has in causing the weak to better themselves.In Norway, live sardines are a few times more expensive than frozen ones. It was said that only one ship could bring live Sardine home, and the ship master kept his method a secret. When he later...
  
   (human resource management) (management) (organizational studies and human resource management) (social psychology)
• Cause and effect
  Causality
  Causality is the relationship between an event and a second event , where the second event is understood as a consequence of the first....
  
  
• Ceiling effect
  Ceiling effect
  The term ceiling effect has two distinct meanings, referring to the level at which an independent variable no longer has an effect on a dependent variable, or to the level above which variance in an independent variable is no longer measured or estimated...
  
   (medical treatment) (statistics)
• Channel capture effect
  Channel capture effect
  The channel capture effect is a phenomenon where one user of a shared medium "captures" the medium for a significant time. During this period , other users are denied use of the medium. This effect was first seen in networks using CSMA/CD on Ethernet...
  
   (ethernet) (network topology)
• Cheerio effect
  Cheerio effect
  In fluid mechanics, the Cheerios effect is the tendency for small wettable floating objects to attract one another. An example of the Cheerios effect is the phenomenon whereby breakfast cereal tends to clump together or cling to the sides of a bowl of milk. It is named for the breakfast cereal...
  
   (fluid mechanics) (physics)
• Cherenkov effect (experimental particle physics) (fundamental physics concepts) (particle physics) (special relativity)
• chilling effect
  Chilling effect
  In a legal context, a chilling effect is the term used to describe the inhibition or discouragement of the legitimate exercise of a constitutional right by the threat of legal sanction. The right that is most often described as being supressed by a chilling effect is the right to free speech...
  
  
• Chorus effect
  Chorus effect
  In music, a chorus effect occurs when individual sounds with roughly the same timbre and nearly the same pitch converge and are perceived as one...
  
   (audio effects) (audio engineering) (effects units) (sound recording)
• Christiansen effect
  Christiansen effect
  The Christiansen effect is named after the Danish physicist Christian Christiansen the effect of this filter is based on the various dispersions of two different media....
  
   (optical filters)
• Christofilos effect
  Christofilos Effect
  The Christofilos Effect refers to the entrapment of charged particles along magnetic lines of force. It was first predicted in 1957 by American amateur scientist Nicholas Christofilos, a salesman for an elevator firm. He sent his calculations to scientists engaged in related research, with little...
  
   (particle physics)
• Cinderella effect
  Cinderella Effect
  The Cinderella effect is a term used by psychologists to describe the high incidence of stepchildren being physically abused, emotionally abused, sexually abused, neglected, murdered, or otherwise mistreated at the hands of their stepparents at significantly higher rates than at the hands of their...
  
   (child abuse)
• Clientele effect
  Clientele effect
  Clientele effect represents the impact on the stock price that investors would cause in reaction to a change in policy of a company. Consequently, dividend policy won't effect the value of the stock as long as clientele exist, dividend policy is irrelevant....
  
   (economics) (finance)
• Cluster effect
  Cluster effect
  The cluster effect is the effect of buyers and sellers of a particular good or service congregating in a certain place and hence inducing other buyers and sellers to relocate there as well.- The Silicon Valley case :...
  
   (economics effects)
• CNN effect
  CNN effect
  The CNN effect is a theory in political science and media studies that postulates that the development of the popular 24-hour international television news channel known as Cable News Network, or CNN, had a major impact on the conduct of states' foreign policy in the late Cold War period and that...
  
   (civil–military relations) (CNN) (news media) (warfare of the modern era)
• Coandă effect
  Coanda effect
  The Coandă effect is the tendency of a fluid jet to be attracted to a nearby surface. The principle was named after Romanian aerodynamics pioneer Henri Coandă, who was the first to recognize the practical application of the phenomenon in aircraft development....
  
   (aerodynamics) (boundary layers) (physical phenomena)
• Coattail effect
  Coattail effect
  The coattail effect is the tendency for a popular political party leader to attract votes for other candidates of the same party in an election...
  
   (political terms)
• Cocktail party effect
  Cocktail party effect
  The cocktail party effect describes the ability to focus one's listening attention on a single talker among a mixture of conversations and background noises, ignoring other conversations. The effect enables most people to talk in a noisy place...
  
   (acoustical signal processing) (attention)
• Cohort effect
  Cohort effect
  The term cohort effect is used in social science to describe variations in the characteristics of an area of study over time among individuals who are defined by some shared temporal experience or common life experience, such as year of birth, or year of exposure to radiation.Cohort effects are...
  
  
• Common-ion effect
  Common-ion effect
  The common ion effect is an effect which results when two substances, which both ionize to give the same ion, are involved in a chemical equilibrium.-Solubility effects:...
  
   (ions) (physical chemistry)
• Compton effect (astrophysics) (atomic physics) (foundational quantum physics) (observational astronomy) (quantum electrodynamics) (X-rays)
• Contrast effect
  Contrast effect
  A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition and related performance as a result of immediately previous or simultaneous exposure to a stimulus of lesser or greater value in the same dimension...
  
   (cognition) (cognitive biases) (perception) (vision)
• Coolidge effect
  Coolidge effect
  In biology and psychology, the Coolidge effect is a phenomenon—seen in nearly every mammalian species in which it has been tested—whereby males exhibit continuous sexual activity if they are introduced to receptive sexual partners, but will eventually stop having sex if the partner has already...
  
   (jokes) (sexual attraction)
• Coriolis effect
  Coriolis effect
  In physics, the Coriolis effect is a deflection of moving objects when they are viewed in a rotating reference frame. In a reference frame with clockwise rotation, the deflection is to the left of the motion of the object; in one with counter-clockwise rotation, the deflection is to the right...
  
   (atmospheric dynamics) (classical mechanics) (force) (physical phenomena) (urban legends)
• Cotton effect
  Cotton effect
  The Cotton effect is the characteristic change in optical rotatory dispersion and/or circular dichroism in the vicinity of an absorption band of a substance....
  
   (atomic, molecular, and optical physics) (polarization)
• Cotton–Mouton effect (magnetism) (optics)
• Crabtree effect
  Crabtree effect
  Named after the English biochemist Herbert Grace Crabtree, the Crabtree effect describes the phenomenon whereby the yeast, Saccharomyces cerevisiae, produces ethanol aerobically in the presence of high external glucose concentrations rather than producing biomass via the tricarboxylic acid cycle,...
  
   (biochemistry)
• Cross-race effect
  Cross-race effect
  Cross-race effect is the tendency for people of one race to have difficulty recognizing and processing faces and facial expressions of members of a race or ethnic group other than their own....
  
   (face recognition)
• CSI effect
  CSI Effect
  The CSI effect, also known as the CSI syndrome and the CSI infection, is any of several ways in which the exaggerated portrayal of forensic science on crime television shows such as CSI: Crime Scene Investigation influences public perception...
  
   (criminal law) (criminology) (CSI television series) (psychology) (television terminology)
• Cytopathic effect
  Cytopathic effect
  Cytopathic effect or cytopathogenic effect refers to degenerative changes in cells, especially in tissue culture, and may be associated with the multiplication of certain viruses....
  
   (microbiology terms)

D

• De Haas–van Alphen effect (condensed matter) (magnetism) (quantum physics)
• De Sitter effect
  De Sitter effect
  In astrophysics, the term de Sitter effect has been applied to two unrelated phenomena:* de Sitter double star experiment...
  
   (astrophysics)
• Debye–Falkenhagen effect
• Decoy effect
  Decoy effect
  In marketing, the decoy effect is the phenomenon whereby consumers will tend to have a specific change in preference between two options when also presented with a third option that is asymmetrically dominated...
  
   (consumer behavior) (decision theory) (economic theories) (finance theory) (marketing)
• Delay (audio effect)
  Delay (audio effect)
  Delay is an audio effect which records an input signal to an audio storage medium, and then plays it back after a period of time. The delayed signal may either be played back multiple times, or played back into the recording again, to create the sound of a repeating, decaying echo.-Early delay...
  
   (audio effects) (effcts units) (musical techniques)
• Dellinger effect
  Dellinger effect
  The Dellinger effect is a fadeout of short-wave radios, caused by increased ionization of the D region of the ionosphere due to solar flares.The effect was discovered by John Howard Dellinger...
  
   (radio communications)
• Dember effect
  Dember effect
  In physics, the Dember effect is when the electron current flowing from a cathode subjected to both illumination and a simultaneous electron bombardment is greater than the sum of the photoelectric current and the secondary emission current ....
  
   (electrical phenomena) (physics)
• Demo effect
  Demo effect
  Demo effects are computer-based real-time visual effects found in demos created by the demoscene.The main purpose of demo effects in demos is to show off the skills of the programmer...
  
   (demoscene)
• Demonstration effect
  Demonstration effect
  Demonstration effects are effects on the behavior of individuals caused by observation of the actions of others and their consequences. The term is particularly used in political science and sociology to describe the fact that developments in one place will often act as a catalyst in another...
  
   (human behavior) (sociological terms)
• Denomination effect
  Denomination effect
  The denomination effect is a theoretical form of cognitive bias relating to currency, whereby people are less likely to spend larger bills than their equivalent value in smaller bills. It was proposed by Priya Raghubir and Joydeep Srivastava in their 2009 paper "Denomination Effect".Joffe-Walt,...
  
   (behavioral economics)
• Diderot effect
  Diderot effect
  The Diderot effect is a social phenomenon related to consumer goods which either posits that form culturally defines groups that are considered cohesive or refers to a process of spiralling consumption resulting from dissatisfaction induced by a new possession...
  
   (anthropology) (consumer behaviour)
• Ding Hai effect
  Ding Hai Effect
  The Ting Hai effect , Adam Cheng effect or Chiu-Koon effect is a peculiar stock market phenomenon. The phenomenon is observed that whenever Hong Kong actor Adam Cheng stars in a new television show, there is a sudden and unexplained drop in the stock market...
  
   (economy of Hong Kong) (Hong Kong culture)
• Direct effect
  Direct effect
  Direct effect is the principle of European Union law according to which provisions of Union law may, if appropriately framed, confer rights and impose obligations on individuals which the courts of European Union member states are bound to recognise and enforce...
  
   (European Union law)
• Disposal tax effect
  Disposal tax effect
  The situation of additional taxes or tax savings resulting from selling the last item of its class in an inventory due to difference between its undepreciated capital cost and its salvage value .-Overview:...
  
   (economics and finance) (finance) (taxation)
• Disposition effect
  Disposition effect
  The disposition effect is an anomaly discovered in behavioral finance. It relates to the tendency of investors to sell shares whose price has increased, while keeping assets that have dropped in value...
  
   (economics and finance)
• Dole effect
  Dole effect
  The Dole effect describes an inequality in the ratio of the heavy isotope 18O to the lighter 16O, measured in the atmosphere and seawater. This ratio is usually denoted δ18O....
  
   (climatology) (oxygen) (paleoclimatology) (photosynthesis)
• Domino effect
  Domino effect
  The domino effect is a chain reaction that occurs when a small change causes a similar change nearby, which then will cause another similar change, and so on in linear sequence. The term is best known as a mechanical effect, and is used as an analogy to a falling row of dominoes...
  
   (physic) (politics)
• Doppler effect
  Doppler effect
  The Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...
  
   (Doppler effects) (radio frequency propagation) (wave mechanics)
• Downing effect (psychology)
• Droste effect
  Droste effect
  The Droste effect is a specific kind of recursive picture, one that in heraldry is termed mise en abyme. An image exhibiting the Droste effect depicts a smaller version of itself in a place where a similar picture would realistically be expected to appear. This smaller version then depicts an even...
  
   (artistic techniques)
• Dunning–Kruger effect (personality) (social psychology)

E

• Early effect
  Early Effect
  The Early effect is the variation in the width of the base in a bipolar junction transistor due to a variation in the applied base-to-collector voltage, named after its discoverer James M. Early...
  
   (transistors)
• Eberhard effect
  Eberhard effect
  In photographic science, the Eberhard effect, named after Gustav Eberhard, is a special case of two Mackie lines when narrow areas of high and low densities In photographic science, the Eberhard effect, named after Gustav Eberhard, is a special case of two Mackie lines when narrow areas of high and...
  
   (science of photography)
• Edge effect
  Edge effect
  The edge effect in ecology is the effect of the juxtaposition or placing side by side of contrasting environments on an ecosystem.This term is commonly used in conjunction with the boundary between natural habitats, especially forests, and disturbed or developed land. Edge effects are especially...
  
   (ecological succession) (ecology)
• Edison effect (atomic physics) (electricity) (Thomas Edison) (vacuum tubes)
• Efimov effect (physics)
• Einstein effect (disambiguation), several different effects in physics
• Einstein–de Haas effect (science)
• Electro-optic effect
  Electro-optic effect
  An electro-optic effect is a change in the optical properties of a material in response to an electric field that varies slowly compared with the frequency of light...
  
   (nonlinear optics)
• Electrocaloric effect
  Electrocaloric effect
  The electrocaloric effect is phenomenon in which a material shows a reversible temperature change under an applied electric field. It is often considered to be the physical inverse of the pyroelectric effect....
  
   (cooling technology) (heat pumps)
• Electron-cloud effect
  Electron-Cloud Effect
  The electron-cloud effect is a phenomenon associated with particle accelerators.- Explanation :Electron clouds are created when accelerated charged particles disturb stray electrons already floating in the tube, and bounce or slingshot the electrons into the wall. These stray electrons can be...
  
   (particle accelerators) (physics)
• ELIZA effect
  ELIZA effect
  The ELIZA effect, in computer science, is the tendency to unconsciously assume computer behaviors are analogous to human behaviors.In its specific form, the ELIZA effect refers only to "the susceptibility of people to read far more understanding than is warranted into strings of symbols —...
  
   (artificial intelligence) (human-computer interaction) (propositional fallacies)
• Embedding effect
  Embedding effect
  The embedding effect is an issue in environmental economics.The effect suggests the contingent valuation method is not an unbiased approach to measuring policy impacts for cost-benefit analysis of environmental, and other government, policies. Few government policies are independent of any other...
  
   (environmental economics)
• Emerson effect
  Emerson effect
  The Emerson effect is the increase in the rate of photosynthesis after exposure to light of wavelength 670 nm and 700 nm, respectively. When simultaneously exposed to light of both wavelengths the rate of photosynthesis increases.-History:...
  
   (photosynthesis)
• Endowment effect
  Endowment effect
  In behavioral economics, the endowment effect is a hypothesis that people value a good or service more once their property right to it has been established. In other words, people place a higher value on objects they own than objects that they do not...
  
   (behavioral finance) (cognitive biases) (psychological theories)
• Enhanced Permeability and Retention effect
  Enhanced Permeability and Retention effect
  The Enhanced Permeability and Retention effect is the property by which certain sizes of molecules tend to accumulate in tumor tissue much more than they do in normal tissues...
  
   (medicine)
• Eötvös effect
  Eötvös effect
  The Eötvös effect is the change in perceived gravitational force caused by the change in centrifugal acceleration resulting from eastbound or westbound velocity...
  
   (geodesy) (topography)
• Epps effect
  Epps effect
  In econometrics and time series analysis, the Epps effect, named after T. W. Epps, is the phenomenon that the empirical correlation between the returns of two different stocks decreases as the sampling frequency of data increases. The phenomenon is caused by non-synchronous/asynchronous...
  
   (econometrics) (statistical terminology) (statistics)
• Espresso crema effect
  Espresso crema effect
  In materials science, the espresso crema effect is an analogue model for superficial material alteration. Alteration processes such as weathering can influence the physical character and chemical composition of matter near the surface, without affecting the bulk medium beneath...
  
   (earth phenomena) (geology)
• Ettinghausen effect
  Ettinghausen effect
  The Ettingshausen Effect is a thermoelectric phenomenon that affects electric current in a conductor when a magnetic field is present....
  
   (condensed matter) (electrodynamics) (thermodynamics)
• Evershed effect
  Evershed effect
  The Evershed effect, named after the British astronomer John Evershed, is the radial flow of gas across the photospheric surface of the penumbra of sunspots from the inner border with the umbra towards the outer edge....
  
   (physics) (solar phenomena)
• Exciter (effect)
  Exciter (effect)
  An Exciter is an audio signal processing technique used to enhance a signal by dynamic equalization, phase manipulation, harmonic synthesis of high frequency signals, and through the addition of subtle harmonic distortion...
  
   (audio effects) (effects units)
• Expectancy effect
  Expectancy effect
  Expectancy effect may refer to:*Observer-expectancy effect*Subject-expectancy effect...
  
  

F

• Fahraeus–Lindquist effect (blood) (fluid dynamics) (molecular and cellular biology)
• False consensus effect
  False consensus effect
  In psychology, the false consensus effect is a cognitive bias whereby a person tends to overestimate how much other people agree with him or her. There is a tendency for people to assume that their own opinions, beliefs, preferences, values and habits are 'normal' and that others also think the...
  
   (cognitive biases) (futurology) (group processes) (psychological theories) (sustainability)
• Faraday effect
  Faraday effect
  In physics, the Faraday effect or Faraday rotation is a Magneto-optical phenomenon, that is, an interaction between light and a magnetic field in a medium...
  
   (magnetism) (optics)
• Ferroelectric effect (condensed matter physics) (electrical phenomena)
• Fink effect
  Fink Effect
  The Fink effect, also known as "diffusion anoxia", "diffusion hypoxia",or the "third gas effect",is a factor that influences the Po2 within the alveolus. When soluble gases are breathed in large quantities can be dissolved in body fluids rapidly...
  
   (anesthesia) (diffusion)
• Flaming sword (effect)
  Flaming sword (effect)
  A flaming sword is a sword that has been coated with some type of combustible fuel, with the fuel being set on fire. This is most widely done for entertainment purposes in circuses, magic performances and other forms of display as a side act of sword swallowers, fire eating, etc.- External links :*...
  
   (fire arts) (special effects)
• Floating body effect
  Floating body effect
  The floating body effect is the effect of dependence of the body potential of a transistor realized by the silicon on insulator technology on the history of its biasing and the carrier recombination processes. The transistor's body forms a capacitor against the insulated substrate...
  
   (electronics) (semiconductors)
• Floodgate effect
  Floodgate Effect
  A floodgate effect is situation in which a small action can result in a far greater effect with no easily discernible limit. The original analogy is that of a floodgate, which once opened, no matter how minutely, will allow water to flow from either side through the gate until both sides are...
  
   (social phenomena) (sociology)
• Floor effect
  Floor effect
  In statistics, the term floor effect refers to when data cannot take on a value lower than some particular number, called the floor.An example of this is when an IQ test is given to young children who have either been given training or have been given no training...
  
   (statistics)
• Florence Nightingale effect
  Florence Nightingale effect
  The Florence Nightingale effect is a term used to describe a doctor's, nurse's or other caregiver's development of feelings for his/her patient. This effect causes a feeling much like infatuation, love or sexual attraction to come over the caregiver regarding a patient, even if very little...
  
   (Florence Nightingale) (love) (psychology)
• Flutie effect
  Flutie effect
  The Flutie Effect or Flutie Factor refers to the phenomenon of having a successful college sports team increase the exposure and prominence of a university...
  
   (student sport)
• Flynn effect
  Flynn effect
  The Flynn effect is the name given to a substantial and long-sustained increase in intelligence test scores measured in many parts of the world. When intelligence quotient tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100...
  
   (futurology) (intelligence) (psychological theories) (psychometrics) (race and intelligence controversy)
• Focusing effect (cognitive biases)
• Forbush effect (cosmic rays) (solar phenomena)
• Forer effect
  Forer effect
  The Forer effect is the observation that individuals will give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically for them, but are in fact vague and general enough to apply to a wide range of people...
  
   (cognitive biases) (history of astrology) (psychological theories)
• Founder effect
  Founder effect
  In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall...
  
   (ecology) (population genetics)
• Fractional quantum Hall effect
  Fractional quantum Hall effect
  The fractional quantum Hall effect is a physical phenomenon in which the Hall conductance of 2D electrons shows precisely quantised plateaus at fractional values of e^2/h. It is a property of a collective state in which electrons bind magnetic flux lines to make new quasiparticles, and excitations...
  
   (physics)
• Franssen effect
  Franssen effect
  The Franssen effect is an auditory illusion where the listener incorrectly localizes a sound. It was found in 1960 by Nico V. Franssen. There are two classical experiments, which are related to the Franssen effect, called Franssen effect F1 and Franssen effect F2.-Setup:There are two speakers to...
  
   (acoustics) (sound perception)
• Franz–Keldysh effect (condensed matter) (electronic engineering) (electronics) (optics) (optoelectronics)
• Free surface effect
  Free Surface Effect
  The free surface effect is one of several mechanisms which can cause a craft to become unstable and roll over . It refers to the tendency of liquids — and of aggregates of small solid objects, like seeds, gravel, or crushed ore which can act as liquids — to slosh about: to move in response to...
  
   (fluid mechanics)
• Front projection effect
  Front projection effect
  A front projection effect is an in-camera visual effects process in film production for combining foreground performance with pre-filmed background footage...
  
   (film production)
• Fujiwhara effect
  Fujiwhara effect
  The Fujiwhara effect or Fujiwara interaction, named after Sakuhei Fujiwhara, is a type of interaction between two nearby cyclonic vortices, causing them to appear to "orbit" each other.-Description:...
  
   (tropical cyclone meteorology) (vortices)
• Full screen effect
  Full screen effect
  A full screen effect is a graphics technique that is applied to the entire screen, usually in postprocessing stage...
  
   (computer graphics) (demo effects)

G

• Garshelis effect
  Garshelis Effect
  The Garshelis effect is the effect wherein a circumferentially magnetized rod of ferromagnetic, magnetostrictive material generates a net axial magnetic field in response to an applied torque....
  
   (electric and magnetic fields in matter) (magnetism) (physics)
• Gauche effect (stereochemistry)
• Generation effect
  Generation effect
  The generation effect refers to the robust finding that information will be better remembered if it is generated rather than simply read. For example, you are more likely to remember the word "orangutan" if you generate it from the fragment "or_ng_ta_" than if you simply see the word in its...
  
   (cognitive biases) (memory biases) (psychological theories)
• Geodetic effect
  Geodetic effect
  The geodetic effect represents the effect of the curvature of spacetime, predicted by general relativity, on a vector carried along with an orbiting body...
  
   (relativity)
• Gerschenkron effect
  Gerschenkron effect
  The Gerschenkron effect was developed by Alexander Gerschenkron, and claims that changing the base year for an index determines the growth rate of the index.This description is from the OECD website :...
  
   (economic development) (economic systems) (economics and finance) (econometrics) (index numbers) (national accounts)r
• Giant magnetoresistive effect
  Giant magnetoresistive effect
  Giant magnetoresistance is a quantum mechanical magnetoresistance effect observed in thin-film structures composed of alternating ferromagnetic and non-magnetic layers...
  
   (condensed matter physics) (electric and magnetic fields in matter) (quantum electronics) (spintronics)
• Gibbons–Hawking effect (general relativity)
• Gibbs–Donnan effect (biology) (physics)
• Gibbs–Thomson effect (petrology) (thermodynamics)
• Glass house effect
  Glass house effect
  Glass House Effect , is the resulting phenomenon brought on by an awareness that one is subject to ubiquitous surveillance. In corporate environments, the transparency is considered a good idea, as it is believed this discourages corporate crime and other misfeasance.GHE can induce an overwhelming...
  
   (culture) (surveillance)
• Glasser effect
  Glasser effect
  The Glasser effect describes the creation of singularities in the flow field of a magnetically confined plasma when small resonant preturbations modify the gradient of the pressure field.- External links :*...
  
   (physics)
• Goos–Hänchen effect (optical phenomena)
• Great Salt Lake effect
  Great Salt Lake effect
  The Great Salt Lake effect is a small but detectable influence on the local climate and weather around the Great Salt Lake in Utah, United States. In particular, snowstorms are a common occurrence over the region and have major socio-economic impacts due to their significant precipitation amounts...
  
   (natural history of Utah)
• Green-beard effect
  Green-beard effect
  The gene-centered view of evolution postulates that natural selection will increase the frequency of those genes whose phenotypic effects ensure their successful replication...
  
   (evolution) (evolutionary biology) (game theory) (selection)
• Greenhouse effect
  Greenhouse effect
  The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere...
  
   (atmosphere) (atmospheric radiation) (climate change feedbacks and causes) (climate forcing)
• Ground effect
  Ground effect
  As it pertains to fixed wing aircraft, "ground effect" refers to the increased lift and decreased drag that an aircraft airfoil or wing generates when an aircraft is about one wingspan's length or less over the ground...
  
   (aerodynamics)
• Gull effect
  Gunn diode
  A Gunn diode, also known as a transferred electron device , is a form of diode used in high-frequency electronics. It is somewhat unusual in that it consists only of N-doped semiconductor material, whereas most diodes consist of both P and N-doped regions...
  
   (diodes) (microwave technology) (physics) (terahertz technology)

H

• Haas effect
  Haas effect
  The Haas effect is a psychoacoustic effect, described in 1949 by Helmut Haas in his Ph.D. thesis. It is often equated with the underlying precedence effect .- Experiments and findings :...
  
   (audio engineering) (sound) (speakers)
• Haldane effect
  Haldane effect
  The Haldane effect is a property of hemoglobin first described by the Scottish physician John Scott Haldane. Deoxygenation of the blood increases its ability to carry carbon dioxide; this property is the Haldane effect. Conversely, oxygenated blood has a reduced capacity for carbon...
  
   (hematology) (hemoproteins) (protein)
• Hall effect
  Hall effect
  The Hall effect is the production of a voltage difference across an electrical conductor, transverse to an electric current in the conductor and a magnetic field perpendicular to the current...
  
   (condensed matter physics) (electric and magnetic fields in matter)
• Hall of mirrors effect (computer graphic artifacts) (Doom) (id software) (video game glitches)
• Halo effect
  Halo effect
  The halo effect is a cognitive bias whereby one trait influences another trait or traits of that person or object. This is very common among physically attractiveness...
  
   (cognitive biases) (educational psychology) (logical fallacies) (social psychology)
• Hanbury Brown and Twiss effect (quantum optics)
• Harem effect
  Harem effect
  The harem effect is an example of situational sexual behaviour in which women confined in a harem practice lesbianism due to lack of male contact. This is similar to prison sexuality in that those involved would, presumably, be exclusively heterosexual given the option....
  
   (harem) (human sexuality) (sex) (sexual orientation and identity) (sexual orientation and society)
• Hawthorne effect
  Hawthorne effect
  The 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...
  
   (educational psychology) (psychological theories) (social phenomena)
• Health effect
  Health effect
  Health effects are changes in health resulting from exposure to a source. Health effects are an important consideration in many areas, such as hygiene, pollution studies, workplace safety, nutrition and health sciences in general...
  
   (health) (health effectors) (pollution)
• Holtzman effect
  Holtzman effect
  The Holtzman effect is a fictional scientific phenomenon in the Dune universe created by Frank Herbert, beginning with the 1965 novel Dune...
  
   (Dune technology) (physics in fiction)
• Horizon effect
  Horizon effect
  The horizon effect is a problem in artificial intelligence where, in many games, the number of possible states or positions is immense and computers can only feasibly search a small portion of it, typically a few ply down the game tree...
  
   (artificial intelligence) (game artificial intelligence)
• Hostile media effect
  Hostile media effect
  The hostile media effect, sometimes called the hostile media phenomenon, refers to the finding that people with strong biases toward an issue perceive media coverage as biased against their opinions, regardless of the reality...
  
   (cognitive biases) (criticism of journalism) (journalism standards) (psychological theories)
• Hot chocolate effect
  Hot chocolate effect
  The Hot Chocolate Effect is a phenomenon of wave mechanics first documented in 1982 by Frank Crawford, where the pitch heard from tapping a cup of hot liquid rises after the addition of a soluble powder...
  
   (acoustics) (physics) (wave mechanics)
• Hundredth monkey effect (behavioral science) (New Age) (urban legends)
• Hydrophobic effect
  Hydrophobic effect
  The hydrophobic effect is the observed tendency of nonpolar substances to aggregate in aqueous solution and exclude water molecules. The name, literally meaning "water-fearing," describes the segregation and apparent repulsion between water and nonpolar substances...
  
   (chemical bonding) (supramolecular chemistry)
• Hyperchromic effect (biochemistry)
• Hypersonic effect
  Hypersonic effect
  The hypersonic effect is a term coined to describe a phenomenon reported in a controversial scientific study by Tsutomu Oohashi et al., which supports the idea that although humans cannot consciously hear sounds at frequencies above approximately 20 kHz, the presence or absence of those...
  
   (acoustics) (hearing) (psychology) (ultrasound)

I

• Ideomotor effect
  Ideomotor effect
  The ideomotor effect is a psychological phenomenon wherein a subject makes motions unconsciously. As in reflexive responses to pain, the body sometimes reacts reflexively to ideas alone without the person consciously deciding to take action. For instance, tears are produced by the body...
  
  
• Imbert–Fedorov effect (optical phenomena)
• In-camera effect
  In-camera effect
  An in-camera effect is any special effect in a video or movie that is created solely by using techniques in and on the camera and/or its parts. The in-camera effect is defined by the fact that the effect exists on the original camera negative or video recording before it is sent to a lab or modified...
  
   (filming) (special effects)
• Incidental effect
  Incidental effect
  Incidental effect is a concept in European Union Law that allows the use of indirect effect of EU directives in private legal actions. While an individual cannot be sued for failure to comply with an EU directive, the state's failure to comply can be an incidental factor in a suit against an...
  
   (European Union law)
• Indirect effect
  Indirect effect
  Indirect effect describes a situation where national courts are required to interpret national law in line with an unimplemented or badly implemented directive, as opposed to ignoring national law in preference to the directive as occurs when direct effect is invoked...
  
   (European Union law)
• Inductive effect
  Inductive effect
  In chemistry and physics, the inductive effect is an experimentally observable effect of the transmission of charge through a chain of atoms in a molecule by electrostatic induction...
  
   (chemical bonding)
• Inert pair effect
  Inert pair effect
  The inert pair effect is the tendency of the outermost s electrons to remain nonionized or unshared in compounds of post-transition metals. The term inert pair effect is often used in relation to the increasing stability of oxidation states that are 2 less than the group valency for the heavier...
  
   (atomic physics) (inorganic chemistry) (quantum chemistry)
• inertial supercharging effect (automobile) (engine technology)
• Inner-platform effect
  Inner-platform effect
  The inner-platform effect is the tendency of software architects to create a system so customizable as to become a replica, and often a poor replica, of the software development platform they are using...
  
   (anti-patterns)
• International Fisher effect
  International fisher effect
  The International Fisher effect is a hypothesis in international finance that says that the difference in the nominal interest rates between two countries determines the movement of the nominal exchange rate between their currencies, with the value of the currency of the country with the lower...
  
   (economics and finance) (finance theories) (interest rates)
• Inverse Doppler effect
  Inverse Doppler effect
  While the usual Doppler effect means that the frequency increases if the observer approaches the source – and decreases as they move away from each other – the theorists have speculated, since 1943, about the possibility that these rules may be interchanged...
  
   (Doppler effects) (wave mechanics)
• Inverse Faraday effect (electric and magnetic fields in matter) (optical phenomena)

J

• Jack-in-the-box effect
  Jack-in-the-Box Effect
  The Jack-in-the-box effect refers to a specific effect of a catastrophic kill on a tank or other turreted armored vehicle in which an ammunition explosion causes the tank's turret to be violently blown off the chassis and into the air...
  
   (military) (military slang and jargon) (tanks)
• Jahn–Teller effect (condensed matter physics) (inorganic chemistry) (organometallic chemistry) (quantum chemistry)
• January effect
  January effect
  The January effect is a calendar-related anomaly in the financial market where financial security prices increase in the month of January. This creates an opportunity for investors to buy stock for lower prices before January and sell them after their value increases.Therefore, the main...
  
   (behavioral finance) (economics and finance) (market trends) (stock market)
• Janus effect
  Janus Effect
  The Janus effect is a fundamental characteristic of an entity that possesses the ability to interact with others in both authoritative and dependence roles.- Origin :Janus was a Roman god with two faces; one looking forward and the other looking back....
  
   (effects) (sociology)
• Johnsen–Rahbek effect (classical mechanics) (electrical engineering)
• Joule-Thomson effect
  Joule-Thomson effect
  In thermodynamics, the Joule–Thomson effect or Joule–Kelvin effect or Kelvin–Joule effect describes the temperature change of a gas or liquid when it is forced through a valve or porous plug while kept insulated so that no heat is exchanged with the environment. This procedure is called a...
  
   (thermodynamics)
• Josephson effect
  Josephson effect
  The Josephson effect is the phenomenon of supercurrent across two superconductors coupled by a weak link...
  
   (condensed matter physics) (sensors) (superconductivity)
• Jupiter effect
  Jupiter effect
  The Jupiter Effect was a best-selling book by John Gribbin, Ph.D., and Stephen Plagemann that predicted that an alignment of the planets of the solar system would create a number of catastrophes, including a great earthquake on the San Andreas Fault, on March 10, 1982...
  
   (astronomy) (science book)

K

• Kadenacy effect
  Kadenacy effect
  The Kadenacy effect is an effect of pressure-waves in gases. It is named after Michel Kadenacy who obtained a French patent for an engine utilizing the effect in 1933. There are also European and US patents...
  
   (automobile parts) (engine technology)
• Kapitsa–Dirac effect (physics)
• Kappa effect
  Kappa effect
  -Introduction:The Kappa Effect is a psychological phenomenon related to the perception of distance, time and speed. It is a temporal illusion that, in some cases, can alter one’s judgement of time. The Kappa effect arises when observers judge the amount of elapsed time between two stimuli in a...
  
   (geography) (psychology)
• Kautsky effect
  Kautsky effect
  Kautsky effect is a phenomenon consisting on a typical variation on the behavior of a plant fluorescence when is exposed to light. It was discovered in 1931 by H. Kautsky and A...
  
   (fluorescence)
• Kaye effect
  Kaye Effect
  The Kaye Effect is a property of complex liquids which was first described by the British engineer Alan Kaye in 1963.While pouring one viscous mixture of an organic liquid onto a surface, the surface suddenly spouted an upcoming jet of liquid which merged with the downgoing one.This phenomenon has...
  
   (fluid dynamics)
• Ken Burns effect
  Ken Burns Effect
  The Ken Burns effect is a popular name for a type of panning and zooming effect used in video production from still imagery.The name derives from extensive use of the technique by American documentarian Ken Burns...
  
   (film techniques)
• Kendall effect
  Kendall effect
  In telecommunications the Kendall effect is a spurious pattern or other distortion in a facsimile.It is caused by unwanted modulation products which arise from the transmission of the carrier signal, and appear in the form of a rectified baseband that interferes with the lower sideband of the...
  
   (telecommunications)
• Kerr effect
  Kerr effect
  The Kerr effect, also called the quadratic electro-optic effect , is a change in the refractive index of a material in response to an applied electric field. The Kerr effect is distinct from the Pockels effect in that the induced index change is directly proportional to the square of the electric...
  
   (nonlinear optics)
• Keynes effect
  Keynes effect
  The Keynes effect is a term used in economics to describe a situation where a change in interest rates affects expenditure more than it affects savings.As prices fall, a given nominal amount of money will become a larger real amount...
  
   (economics and finance) (Keynesian economics)
• Keystone effect
  Keystone effect
  The keystone effect, also known as the tombstone effect, is caused by attempting to project an image onto a surface at an angle, as with a projector not quite centered onto the screen it is projecting on. It is a distortion of the image dimensions, making it look like a trapezoid, the shape of an...
  
   (technology)
• Kinetic depth effect
  Kinetic depth effect
  In visual perception, the kinetic depth effect refers to the phenomenon whereby the three-dimensional structural form of an object can be perceived when the object is moving. In the absence of other visual depth cues, this might be the only perception mechanism available to infer the object's shape...
  
   (perception)
• Kinetic isotope effect
  Kinetic isotope effect
  The kinetic isotope effect is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction. It is also called "isotope fractionation," although this term is somewhat broader in meaning...
  
   (chemical kinetics) (physical organic chemistry)
• Kirkendall effect
  Kirkendall effect
  The Kirkendall effect is the motion of the boundary layer between two metals that occurs as a consequence of the difference in diffusion rates of the metal atoms...
  
   (chemistry) (metallurgy)
• Klein–Nishina effect (quantum field theory)
• Knife-edge effect
  Knife-edge effect
  In electromagnetic wave propagation, the knife-edge effect or edge diffraction is a redirection by diffraction of a portion of the incident radiation that strikes a well-defined obstacle such as a mountain range or the edge of a building....
  
   (radio frequency propagation)
• Kohn effect
  Kohn effect
  The Kohn effect is a dispersion of phonons from the Fermi surface, named for Walter Kohn....
  
   (physics)
• Kondo effect
  Kondo effect
  In physics, the Kondo effect describes the scattering of conduction electrons in a metal due to magnetic impurities. It is a measure of how electrical resistivity changes with temperature....
  
   (condensed matter physics) (electric and magnetic fields in matter) (physical phenomena)
• Kozai effect (astronomy) (celestial mechanics)
• Kuleshov effect
  Kuleshov Effect
  The Kuleshov Effect is a film editing effect demonstrated by Russian filmmaker Lev Kuleshov in the 1910s and 1920s.-Specifics of the Kuleshov effect:...
  
   (cinema of Russia) (cognitive biases) (film editing) (film techniques) (psychological theories)

L

• Lake effect (snow or ice weather phenomena)
• Lake Wobegon effect
  Illusory superiority
  Illusory superiority is a cognitive bias that causes people to overestimate their positive qualities and abilities and to underestimate their negative qualities, relative to others. This is evident in a variety of areas including intelligence, performance on tasks or tests, and the possession of...
  
   (cognitive biases) (psychological theories) (social psychology)
• Landau–Pomeranchuk–Migdal effect (high-energy physics)
• Larsen effect (audio feedback)
• Late effect
  Late effect
  In medicine, a late effect is a condition that appears after the acute phase of an earlier, causal condition has run its course. A late effect can be caused directly by the earlier condition, or indirectly by the treatment for the earlier condition. Some late effects can occur decades later...
  
   (disease)
• Lawn dart effect
  Lawn dart effect
  In psychology, the lawn dart effect occurs when fighter aircraft pilots accelerate horizontally at more than 1 standard gravity. The effect occurs when such extreme stimulation to the vestibular system leads to the perception that the aircraft is climbing; he then pushes the joystick forwards to...
  
   (psychology)
• Lazarus effect
  Lazarus effect
  When semiconductor detectors are used in harsh radiation environments, defects begin to appear in the semiconductor crystal lattice as atoms become displaced because of the interaction with the high-energy traversing particles...
  
   (particle detectors)
• LCD memory effect
  LCD memory effect
  Passive matrix addressing takes advantage of hysteresis to display images on liquid crystal displays. Without this effect, passive matrix LCD panels would not be able to display anything. Similarly; Active-matrix LCDs whose pixels use dedicated transistors are sometimes "dead pixels"....
  
   (display technology)
• Lead–lag effect (control theory) (economics and finance)
• Leakage effect
  Leakage effect
  The leakage effect is a concept within the study of tourism. The term refers to the way in which revenue generated by tourism is lost to other countries' economies. Leakage may be so significant in some developing countries that it partially neutralizes the money generated by...
  
   (tourism)
• Learning effect (economics)
  Learning effect (economics)
  In economics, the learning effect is the theory that education increases product if add in results in higher wages....
  
   (economics) (economics terminology)
• Lee–Boot effect (biology) (reproduction)
• Legalized abortion and crime effect
  Legalized abortion and crime effect
  The effect of legalized abortion on crime is the theory that legal abortion reduces crime. Proponents of the theory generally argue that since unwanted children are more likely to become criminals and that an inverse correlation is observed between the availability of abortion and subsequent crime...
  
   (abortion debate) (criminology)
• Leidenfrost effect
  Leidenfrost effect
  The Leidenfrost effect is a phenomenon in which a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapor layer which keeps that liquid from boiling rapidly...
  
   (physical phenomena)
• Lenard effect (physics)
• Lense–Thirring effect (effects of gravitation) (tests of general relativity)
• Leveling effect (chemistry)
• Levels-of-processing effect
  Levels-of-processing effect
  The levels-of-processing effect, identified by Fergus I. M. Craik and Robert S. Lockhart in 1972, describes memory recall of stimuli as a function of the depth of mental processing. Depth of processing falls on a shallow to deep continuum. Shallow processing leads to a fragile memory trace that...
  
   (educational psychology) (psychology) (psychological theories)
• Liquid Sky (effect)
  Liquid Sky (effect)
  Liquid sky is a popular lighting effect used by clubs and similar venues. It consists of a laser scanning in a flat beam above the head of the crowd; as with most laser displays, for the effect to become apparent the air must be misted by a fog machine. The fog makes the beam of the laser visible,...
  
   (lasers) (stage lighting)
• Little–Parks effect (condensed matter physics)
• Lockin effect
  Lockin effect
  In superconductivity, the Lockin Effect refers to the preference of vortex phases to be positioned at certain points within cells of a crystal lattice of an organic superconductor.-References:...
  
   (physics)
• Lombard effect
  Lombard effect
  thumb|250 px|[[Great tit]]s sing at a higher frequency in [[noise pollution|noise polluted]] urban surroundings than quieter ones to help overcome the [[auditory masking]] that would otherwise impair other birds hearing their [[bird vocalization|song]]...
  
   (phonetics) (human voice) (animal communication) (human communication) (noise pollution)
• Lotus effect
  Lotus effect
  The lotus effect refers to the very high water repellence exhibited by the leaves of the lotus flower ....
  
   (nanotechnology)
• Low-frequency effects (film sound production) (technology)
• Lubbert's effect (medicine) (radiography) (radiology)
• Lunar effect
  Lunar effect
  The lunar effect is the theory that there is correlation between specific stages of the Earth's lunar cycle and deviant behavior in human beings...
  
   (moon myths) (pseudoscience)
• Luxemburg–Gorky effect (radio communication) (radio spectrum)

M

• Mach effect
  Mach effect
  The "Mach Effect" can refer to one of the following two things:* Mach bands are an optical illusion that are often referred to also as "the mach effect"....
  
  
• Magnetic isotope effect
  Magnetic Isotope Effect
  Magnetic isotope effects arise when a chemical reaction involves spin-selective processes, such as the radical pair mechanism. The result is that some isotopes react preferentially, depending on their nuclear spin quantum number I. This is in contrast to more familiar mass-dependent isotope effects....
  
   (physics)
• Magneto-optic effect
  Magneto-optic effect
  A magneto-optic effect is any one of a number of phenomena in which an electromagnetic wave propagates through a medium that has been altered by the presence of a quasistatic magnetic field...
  
   (electric and magnetic fields in matter) (optical phenomena)
• Magneto-optic Kerr effect
  Magneto-optic Kerr effect
  Magneto-optic Kerr effect is one of the magneto-optic effects. It describes the changes of light reflected from magnetized media.-Definition:The light that is reflected from a magnetized surface can change in both polarization and reflected intensity...
  
   (condensed matter physics) (electric and magnetic fields in matter) (optical phenomena)
• Magnus effect
  Magnus effect
  The Magnus effect is the phenomenon whereby a spinning object flying in a fluid creates a whirlpool of fluid around itself, and experiences a force perpendicular to the line of motion...
  
   (fluid dynamics)
• Mallenby effect
• Malter effect
  Malter effect
  The Malter effect is named after Zachary Malter, who first described the effect. Following exposure to ionizing radiation , secondary electron emission from the surface of a thin insulating layer results in the establishment of a positive charge on the surface...
  
   (physics)
• Marangoni effect
  Marangoni effect
  The Marangoni effect is the mass transfer along an interface between two fluids due to surface tension gradient...
  
   (fluid dynamics) (fluid mechanics) (physical phenomena)
• Mark Twain effect
  Mark Twain effect
  In some stock markets, the Mark Twain effect is the phenomenon of stock returns in October being lower than in other months. The name comes from the following quotation in Mark Twain's Pudd'nhead Wilson: "October. This is one of the peculiarly dangerous months to speculate in stocks...
  
   (economics and finance) (stock market)
• Martha Mitchell effect
  Martha Mitchell effect
  The Martha Mitchell effect is the process by which a psychiatrist, psychologist, or other mental health clinician mistakes the patient's perception of real events as delusional and misdiagnoses accordingly.-Description:...
  
   (psychological theories) (psychosis)
• Massenerhebung effect
  Massenerhebung effect
  The Massenerhebung effect describes variation in the tree line based on mountain size and location. In general, mountains surrounded by large ranges will tend to have higher tree lines than more isolated mountains due to heat retention and wind shadowing...
  
   (trees)
• Maternal age effect (developmental biology)
• Maternal effect
  Maternal effect
  A maternal effect is a situation where the phenotype of an organism is determined not only by the environment it experiences and its genotype, but also by the environment and phenotype of its mother...
  
   (developmental biology)
• Matthew effect
  Matthew effect
  The Matthew effect may refer to:* Matthew effect , the phenomenon in sociology where "the rich get richer and the poor get poorer"* Matthew effect , the phenomenon in education that has been observed in research on how new readers acquire the skills to read...
  
   (adages) (sociology)
• McClintock effect
  McClintock effect
  Menstrual synchrony is a phenomenon reported in 1971 wherein the menstrual cycles of women who lived together reportedly became synchronized over time...
  
   (menstruation)
• McCollough effect
  McCollough effect
  The McCollough effect is a phenomenon of human visual perception in which colorless gratings appear colored depending on the orientation of the gratings. It is an aftereffect requiring a period of induction to produce it...
  
   (optical illusions)
• McGurk effect
  McGurk effect
  The McGurk effect is a perceptual phenomenon which demonstrates an interaction between hearing and vision in speech perception. "It is a compelling illusion in which humans perceive mismatched audiovisual speech as a completely different syllable". The visual information a person gets from seeing a...
  
   (auditory illusions) (perception) (psychological theories)
• Meissner effect
  Meissner effect
  The Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state. The German physicists Walther Meissner and Robert Ochsenfeld discovered the phenomenon in 1933 by measuring the magnetic field distribution outside superconducting tin...
  
   (levitation) (magnetism) (superconductivity)
• Meitner–Hupfeld effect
  Meitner–Hupfeld effect
  The Meitner–Hupfeld effect is an anomalously large scattering of Gamma rays by heavy elements. Later on, the Meitner–Hupfeld effect was explained by a broad theory from which evolved the Standard Model, a theory for explaining the structure of the atomic nucleus...
  
   (particle physics)
• Memory effect
  Memory effect
  Memory effect, also known as battery effect, lazy battery effect or battery memory, is an alleged effect observed in nickel cadmium rechargeable batteries that causes them to hold less charge...
  
   (electric batteries)
• Mesomeric effect
  Mesomeric effect
  The mesomeric effect or resonance effect in chemistry is a property of substituents or functional groups in a chemical compound. The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is...
  
   (chemical bonding)
• Microwave auditory effect
  Microwave auditory effect
  The microwave auditory effect, also known as the microwave hearing effect or the Frey effect, consists of audible clicks induced by pulsed/modulated microwave frequencies. The clicks are generated directly inside the human head without the need of any receiving electronic device...
  
   (cognitive neuroscience) (espionage) (hearing) (human psychology) (less-lethal weapons) (mind control) (sound)
• Mid-domain effect (macroecology) (biogeography)
  Latitudinal gradients in species diversity
  The increase in species richness or biodiversity that occurs from the poles to the tropics, often referred to as the latitudinal diversity gradient , is one of the most widely recognized patterns in ecology. Put another way, in the present day localities at lower latitudes generally have more...
  
   (biodiversity)
• Mikheyev–Smirnov–Wolfenstein effect (particle physics)
• Milky seas effect
  Milky seas effect
  Milky seas is a condition on the open ocean where large areas of seawater are filled with bioluminescent bacteria, causing the ocean to uniformly glow an eerie blue at night...
  
   (aquatic biology) (biological oceanography) (bioluminescence)
• Miller effect
  Miller effect
  In electronics, the Miller effect accounts for the increase in the equivalent input capacitance of an inverting voltage amplifier due to amplification of the effect of capacitance between the input and output terminals...
  
   (electrical engineering) (electronics terms)
• Miniature effect
  Miniature effect
  A miniature effect is a special effect created for motion pictures and television programs using scale models. Scale models are often combined with high speed photography or matte shots to make gravitational and other effects appear convicing to the viewer...
  
   (film and video technology) (film techniques) (scale modeling) (scientific modeling) (special effects) (visual effects)
• Misinformation effect
  Misinformation effect
  The misinformation effect refers to the finding that exposure to misleading information presented between the encoding of an event and its subsequent recall causes impairment in memory. This effect occurs when participants' recall of an event they witnessed is altered by introducing misleading...
  
   (cognitive biases) (psychological theories)
• Missing letter effect
  Missing letter effect
  In cognitive psychology, the missing letter effect refers to the finding that, when people are asked to consciously detect target letters while reading text, they miss more letters in frequent, function words than in less frequent, content words...
  
   (perception) (psychometrics)
• Misznay–Schardin effect (explosives)
• Mohring effect
  Mohring effect
  The Mohring effect is a technical property of transit systems demonstrating increasing returns.In brief, as transit frequencies increase, wait times decrease, demand increases, and transit frequencies can increase again. This is because transit schedules occur over time...
  
   (microeconomics) (transportation)
• Mössbauer effect
  Mössbauer effect
  The Mössbauer effect, or recoilless nuclear resonance fluorescence‎, is a physical phenomenon discovered by Rudolf Mössbauer in 1958. It involves the resonant and recoil-free emission and absorption of γ radiation by atomic nuclei bound in a solid...
  
   (condensed matter physics) (nuclear physics) (physical phenomena)
• Mozart effect
  Mozart effect
  The Mozart effect can refer to: * A set of research results that indicate that listening to Mozart's music may induce a short-term improvement on the performance of certain kinds of mental tasks known as "spatial-temporal...
  
   (education psychology) (popular psychology) (psychological theories) (Wolfgang Amadeus Mozart)
• Mpemba effect
  Mpemba effect
  The Mpemba effect is the observation that warmer water sometimes freezes faster than colder water. Although the observation has been verified, there is no single scientific explanation for the effect.-Historical observations:...
  
   (phase changes) (physical paradoxes) (thermodynamics)
• Mullins effect
  Mullins effect
  The Mullins effect is a particular aspect of the mechanical response in filled rubbers in which the stress-strain curve depends on the maximum loading previously encountered...
  
   (rubber properties)
• Multiple-effect humidification (drinking water) (water supply) (water treatment)
• Munroe effect (explosive weapons) (explosives)

N

• Name letter effect
  Name letter effect
  The name letter effect is one of the widest used measures of implicit self esteem. It represents the idea that an individual prefers the letters belonging to their own name and will select these above other letters in choice tasks....
  
   (psychology)
• Negative (positive) contrast effect
  Negative (positive) contrast effect
  -Negative contrast effect in operant conditioning:In the behavioral theory of operant conditioning, the negative contrast effect is evident when an attempt to reinforce a particular behavior through reward; when the rewards are finally withdrawn or reduced the subject is even less likely to...
  
   (psychology)
• Negativity effect
  Negativity effect
  In psychology, the negativity effect is the tendency of people, when evaluating the causes of the behaviors of a person they dislike, to attribute their positive behaviors to the environment and their negative behaviors to the person's inherent nature...
  
   (cognitive biases) (psychological theories)
• Neglected firm effect
  Neglected firm effect
  The Neglected firm effect is the phenomenon of lesser-known firms producing abnormally high returns on their stocks. The companies that are followed by fewer analysts will earn higher returns on average than companies that are followed by many analysts...
  
   (business analysis)
• Nernst effect
  Nernst effect
  In physics and chemistry, the Nernst Effect is a thermoelectric phenomenon observed when a sample allowing electrical conduction is subjected to a magnetic field and a temperature gradient normal...
  
   (electrodynamics) (thermodynamics)
• Network effect
  Network effect
  In economics and business, a network effect is the effect that one user of a good or service has on the value of that product to other people. When network effect is present, the value of a product or service is dependent on the number of others using it.The classic example is the telephone...
  
   (business models) (economics effects) (information technology) (monopoly [economics]) (networks) (transport economics)
• Non-thermal microwave effect
  Non-thermal microwave effect
  Non-thermal microwave effects have been posited in order to explain unusual observations in microwave chemistry. As the name suggests, the effects are supposed not to require the transfer of microwave energy into thermal energy. Instead, the microwave energy itself directly couples to energy modes...
  
   (chemical kinetics)
• Nordtvedt effect
  Nordtvedt effect
  In theoretical astrophysics, the Nordtvedt effect refers to the relative motion between the Earth and the Moon which would be observed if the gravitational self-energy of a body contributed to its gravitational mass but not its inertial mass...
  
   (astronomy) (astrophysics) (effects of gravitation) (relativity) (theoretical physics)
• Novaya Zemlya effect
  Novaya Zemlya effect
  The Novaya Zemlya effect is a polar mirage caused by high refraction of sunlight between atmospheric thermoclines. The Novaya Zemlya effect will give the impression that the sun is rising earlier than it actually should and depending on the meteorological situation the effect will present the sun...
  
   (arctic) (atmospheric optical phenomena) (atmospheric science) (Novaya Zemlya) (solar phenomena)
• Novelty effect
  Novelty effect
  The novelty effect, in the context of human performance, is the tendency for performance to initially improve when new technology is instituted, not because of any actual improvement in learning or achievement, but in response to increased interest in the new technology...
  
   (learning) (psychology)
• Nuclear Overhauser effect
  Nuclear Overhauser effect
  The Nuclear Overhauser Effect is the transfer of nuclear spin polarization from one nuclear spin population to another via cross-relaxation. It is a common phenomenon observed by nuclear magnetic resonance spectroscopy. The theoretical basis for the NOE was described and experimentally verified...
  
   (chemical physics) (nuclear magnetic resonance) (physical chemistry) (spectroscopy)
• Numerosity adaptation effect
  Numerosity adaptation effect
  The numerosity adaptation effect is a perceptual phenomenon in numerical cognition which demonstrates non-symbolic numerical intuition and exemplifies how numerical percepts can impose themselves upon human brain automatically. This effect was first described in 2008.Presently, this effect is...
  
   (cognitive science) (optical illusions) (perception)
• Nut Island effect
  Nut Island effect
  The Nut Island effect describes a human resources condition in which a team of skilled employees becomes isolated from distracted top managers resulting in a catastrophic loss of the ability of the team to perform an important mission. The term was coined by Paul F. Levy, a former Massachusetts...
  
   (human resource management) (organizational studies and human resource management)

O

• Observer effect
  Observer effect
  Observer effect may refer to:* Observer effect , the impact of observing a process while it is running* Observer effect , the impact of observing a physical system...
  
   (cognitive biases) (philosophy of science) (types of scientific fallacy)
• Observer effect (information technology)
  Observer effect (information technology)
  In information technology, the observer effect is the potential impact of the act of observing a process output while the process is running. For example: if a process uses a log file to record its progress, the process could slow...
  
   (computer programming)
• Observer-expectancy effect
  Observer-expectancy effect
  The observer-expectancy effect is a form of reactivity, in which a researcher's cognitive bias causes them to unconsciously influence the participants of an experiment...
  
  
• Occlusion effect
  Occlusion effect
  The occlusion effect occurs when an object fills the outer portion of a person's ear canal, and that person perceives "hollow" or "booming" echo-like sounds of their own voice. It is caused by bone-conducted sound vibrations reverberating off the object filling the ear canal...
  
   (biology) (otology)
• Octave effect
  Octave effect
  Octave-effect boxes are a type of special effects unit which mix the input signal with a synthesised signal whose musical tone is an octave lower or higher than the original. The synthesised octave signal is derived from the original input signal by halving or doubling the frequency...
  
   (effects units)
• Okorokov effect
  Okorokov effect
  The Okorokov effect is the name given to resonant coherent excitation of heavy ions moving in crystals under channeling conditions. V. Okorokov predicted this effect in 1965 and it was first observed by Sheldon Datz in 1978....
  
   (physics)
• Oligodynamic effect
  Oligodynamic effect
  The oligodynamic effect was discovered in 1893 by the Swiss Karl Wilhelm von Nägeli as a toxic effect of metal ions on living cells, algae, molds, spores, fungi, viruses, prokaryotic and eukaryotic microorganisms, even in relatively low concentrations...
  
   (biology and pharmacology of chemical elements)
• Olivera–Tanzi effect (taxation)
• Online disinhibition effect
  Online disinhibition effect
  In psychology, the online disinhibition effect, also known in popular culture as John Gabriel's Greater Internet Fuckwad Theory , refers to the way people behave on the Internet with less restraint than in real-world situations...
  
   (Internet culture) (psychology)
• Onnes effect (condensed matter physics) (fluid mechanics) (helium)
• Opposition effect (astronomy) (optical phenomena) (observational astronomy) (radiometry) (scattering, absorption and radiative transfer [optics])
• Osborne effect
  Osborne effect
  The Osborne effect is a term referring to the unintended consequence of the announcement of a future product ahead of its availability and its impact upon the sales of the current product....
  
   (marketing)
• Ostrich effect
  Ostrich effect
  In behavioral finance, the ostrich effect is the avoidance of apparently risky financial situations by pretending they do not exist. The name comes from the common legend that ostriches bury their heads in the sand to avoid danger....
  
   (adages)
• Overconfidence effect
  Overconfidence effect
  The overconfidence effect is a well-established bias in which someone's subjective confidence in their judgments is reliably greater than their objective accuracy, especially when confidence is relatively high. For example, in some quizzes, people rate their answers as "99% certain" but are wrong...
  
   (cognitive biases) (psychological theories)
• Overjustification effect
  Overjustification effect
  The overjustification effect occurs when an external incentive such as money or prizes decreases a person's intrinsic motivation to perform a task. According to self-perception theory, people pay more attention to the incentive, and less attention to the enjoyment and satisfaction that they receive...
  
   (educational psychology) (psychological theories) (psychology)
• Overview effect
  Overview effect
  The overview effect is a transcendental, euphoric feeling of universal connection reported by some astronauts during spaceflight, often while viewing the Earth from orbit or from the lunar surface. Third-hand observers of these individuals may also report a noticeable difference in attitude...
  
   (spaceflight) (transcendence) (psychology)

P

• Park effect (psychology)
• Partner effects
  Partner effects
  Partner effects refer to the ways in which a spouse or consensual mate influences the life of their significant other. More specifically, the effect a partner has on another's career and overall occupational status...
  
   (economics) (sociology)
• Paschen–Back effect (atomic physics) (atomic, molecular, and optical physics) (magnetism)
• Pasteur effect
  Pasteur effect
  The Pasteur effect is an inhibiting effect of oxygen on the fermentation process.-Discovery:The effect was discovered in 1857 by Louis Pasteur, who showed that aerating yeasted broth causes yeast cell growth to increase, while conversely, fermentation rate decreases.-Explanation:The effect can be...
  
   (beer and brewery) (biochemistry) (fermentation) (metabolism)
• (Paternal effect: see) maternal effect
  Maternal effect
  A maternal effect is a situation where the phenotype of an organism is determined not only by the environment it experiences and its genotype, but also by the environment and phenotype of its mother...
  
   (developmental biology)
• Pauli effect
  Pauli effect
  The Pauli effect is a term referring to the apparently mysterious 'anecdotal' failure of technical equipment in the presence of certain people. The term was coined using the name of the Austrian theoretical physicist Wolfgang Pauli...
  
   (experimental physics) (parapsychology) (psychokinesis)
• Payne effect
  Payne effect
  The Payne effect is a particular feature of the stress-strain behaviour of rubber, especially rubber compounds containing fillers such as carbon black. It is named after the British rubber scientist A. R. Payne, who made extensive studies of the effect...
  
   (rubber properties)
• Pearson–Anson effect (electronics)
• Peltier–Seebeck effect (thermoelectric effect) (electricity) (HVAC) (physical phenomena) (thermodynamics)
• Peltzman effect
  Peltzman Effect
  The Peltzman effect is the hypothesized tendency of people to react to a safety regulation by increasing other risky behavior, offsetting some or all of the benefit of the regulation...
  
   (economics of regulation) (University of Chicago)
• Penn effect
  Penn effect
  The Penn effect is the economic finding associated with what became the Penn World Table that real income ratios between high and low income countries are systematically exaggerated by gross domestic product conversion at market exchange rates...
  
   (economics effects)
• Petkau effect
  Petkau effect
  The Petkau effect is an early counterexample to linear-effect assumptions usually made about radiation exposure. It was found by Dr. Abram Petkau at the Atomic Energy of Canada Whiteshell Nuclear Research Establishment, Manitoba and published in Health Physics March 1972.Petkau had been...
  
   (radiobiology)
• Phaser (effect)
  Phaser (effect)
  A phaser is an audio signal processing technique used to filter a signal by creating a series of peaks and troughs in the frequency spectrum. The position of the peaks and troughs is typically modulated so that they vary over time, creating a sweeping effect...
  
   (audio effects) (effects units)
• Phillips effect (employment) (inflation)
• Photoacoustic Doppler effect
  Photoacoustic Doppler effect
  The photoacoustic Doppler effect, as its name implies, is one specific kind of Doppler effect, which occurs when an intensity modulated light wave induces a photoacoustic wave on moving particles with a specific frequency. The observed frequency shift is a good indicator of the velocity of the...
  
   (Doppler effects) (radar signal processing) (radio frequency propagation) (wave mechanics)
• Photoelectric effect
  Photoelectric effect
  In the photoelectric effect, electrons are emitted from matter as a consequence of their absorption of energy from electromagnetic radiation of very short wavelength, such as visible or ultraviolet light. Electrons emitted in this manner may be referred to as photoelectrons...
  
   (Albert Einstein) (electrical phenomena) (foundational quantum physics)
• Photorefractive effect
  Photorefractive effect
  The photorefractive effect is a nonlinear optical effect seen in certain crystals and other materials that respond to light by altering their refractive index....
  
   (nonlinear optics)
• Photothermal effect
  Photothermal effect
  Photothermal effect is a phenomenon associated with electromagnetic radiation. It is produced by the photoexcitation of material, resulting in the production of thermal energy ....
  
   (particle physics) (photochemistry) (physics)
• Physical effect
  Physical effect
  Physical effect is transformation at which physical action on an object causes the occurrence of some field or action. As a rule, these are phenomena connected with the transformation of energy or with a change of aggregation state....
  
   (physics)
• Picture superiority effect
  Picture superiority effect
  According to the picture superiority effect, concepts are much more likely to be remembered experientially if they are presented as pictures rather than as words....
  
   (cognitive biases) (educational psychology) (memory biases) (psychological theories)
• Piezoresistive effect
  Piezoresistive effect
  The piezoresistive effect describe the changing resistivity of a semiconductor due to applied mechanical stress. The piezoresistive effect differs from the piezoelectric effect...
  
   (electrical phenomena)
• Pigou effect
  Pigou effect
  The Pigou effect is an economics term that refers to the stimulation of output and employment caused by increasing consumption due to a rise in real balances of wealth, particularly during deflation....
  
   (economics effects)
• Placebo effect
  Placebo effect
  Placebo effect may refer to:* Placebo effect, the tendency of any medication or treatment, even an inert or ineffective one, to exhibit results simply because the recipient believes that it will work...
  
   (bioethics) (clinical research) (experimental design) (history of medicine) (Latin medical phrases) (Latin words and phrases) (medical ethics) (medical terms) (medicinal chemistry) (mind-body interventions) (pharmacology) (psychological theories) (research methods) (theories)
• Plasma effect
  Plasma effect
  The plasma effect is a computer-based visual effect animated in real-time. It uses cycles of changing colours warped in various ways to give an illusion of liquid, organic movement....
  
   (demo effects)
• Plateau effect
  Plateau effect
  A Plateau effect occurs when a formerly effective measure ceases to cause further change. For example, plateau effects may appear in learning, when students experience a dwindling benefit from their learning effort....
  
   (systems science) (metaphors referring to places)
• Pockels effect
  Pockels effect
  The Pockels effect , or Pockels electro-optic effect, produces birefringence in an optical medium induced by a constant or varying electric field. It is distinguished from the Kerr effect by the fact that the birefringence is proportional to the electric field, whereas in the Kerr effect it is...
  
   (cryptography) (nonlinear optics) (polarization)
• Polar effect
  Polar effect
  The Polar effect or electronic effect in chemistry is the effect exerted by a substituent on modifying electrostatic forces operating on a nearby reaction center...
  
   (physical organic chemistry)
• Polar effect (genetics)
  Polar effect (genetics)
  Polar effect in genetics occurs when the mutation of one gene prevents other genes in the same operon from being transcribed....
  
   (genetics)
• Pontoon effect
  Pontoon effect
  The pontoon effect refers to the tendency of a vessel whose flotation depends on lateral pontoons to capsize without warning when a lateral force is applied. The effect can be sudden and dramatic because the vessel is stable and self-righting as greater lateral force is applied, up to the point...
  
   (naval architecture)
• Portevin–Le Chatelier effect
  Portevin–Le Chatelier effect
  The Portevin–Le Chatelier effect describes a serrated stress-strain curve or jerky flow, which some materials exhibit as they undergo plastic deformation, specifically inhomogeneous deformation...
  
   (engineering) (materials science)
• Position-effect variegation
  Position-effect variegation
  Position-effect variegation is a variegation caused by the inactivation of a gene in some cells through its abnormal juxtaposition with heterochromatin....
  
   (genetics)
• Positivity effect
  Positivity effect
  In psychology and cognitive science, the positivity effect is the tendency of people, when evaluating the causes of the behaviors of a person they like or prefer, to attribute the person's inherent disposition as the cause of their positive behaviors and the situations surrounding them as the cause...
  
   (aging) (cognition) (cognitive biases) (memory) (memory biases) (psychological theories) (psychology)
• Poynting effect
  Poynting effect
  The Poynting effect may refer to two unrelated physical phenomena. Neither should be confused with the Poynting–Robertson effect. All of these effects are named after John Henry Poynting, an English physicist.- Chemistry / Thermodynamics :...
  
   (gases)
• Poynting–Robertson effect (celestial mechanics)
• Practical effect
  Practical effect
  A practical effect is a special effect in which a prop appears to work in a situation where it obviously could not in real life . They do not use trick photography or post-production artifice. This type of effect is normally found in live theatre.In film, practical effect denotes an effect produced...
  
   (special effects)
• Pratfall effect
  Pratfall effect
  The pratfall effect is a psychological phenomenon whereby the attractiveness of a person perceived as competent increases if the person commits a blunder. Conversely, the attractiveness of a person perceived as incompetent decreases if the person commits a blunder.-References:Aronson, E.,...
  
   (psychology)
• Precedence effect
  Precedence effect
  The precedence effect or law of the first wavefront is a binaural psychoacoustic effect. It means: If the same sound signal arrives time delayed at a listener from different directions, only the direction of the first arriving sound signal is perceived...
  
   (acoustics) (sound perception)
• Primakoff effect
  Primakoff effect
  Primakoff effect is the resonant production of neutral pseudoscalar mesons by high-energy photons interacting with an atomic nucleus...
  
   (particle physics)
• Priority effect
  Priority effect
  Priority effect is the impact that a particular species can have on ecological community development due to prior arrival at a site ....
  
   (ecology)
• Probe effect
  Probe effect
  Probe effect is unintended alteration in system behavior caused by measuring that system.In code profiling and performance measurements, the delays introduced by insertion/removal of code instrumentation may result in a non-functioning application, or unpredictable behavior.-Examples:In...
  
   (software development philosophies) (system administration)
• Proximity effect (atomic physics)
  Proximity effect (atomic physics)
  At the atomic level, when two atoms come into proximity, the highest energy, or valence, orbitals of the atoms change substantially and the electrons on the two atoms reorganize. One way to probe a correlated state is through the proximity effect. This phenomenon occurs when the correlations...
  
   (nuclear physics) (physics)
• Proximity effect (audio)
  Proximity effect (audio)
  The proximity effect in audio is an increase in bass or low frequency response when a sound source is close to a microphone.-Technical explanation:...
  
   (acoustics)
• Proximity effect (electromagnetism)
  Proximity effect (electromagnetism)
  In a conductor carrying alternating current, if currents are flowing through one or more other nearby conductors, such as within a closely wound coil of wire, the distribution of current within the first conductor will be constrained to smaller regions. The resulting current crowding is termed the...
  
   (electrical engineering)
• Proximity effect (electron beam lithography)
  Proximity effect (electron beam lithography)
  The proximity effect in electron beam lithography is the phenomenon that the exposure dose distribution, and hence the developed pattern, is wider than the scanned pattern, due to the interactions of the primary beam electrons with the resist and substrate...
  
   (condensed matter physics)
• Proximity effect (superconductivity) (superconductivity)
• Pseudocertainty effect
  Pseudocertainty effect
  The pseudocertainty effect is a concept from prospect theory. It refers to people's tendency to perceive an outcome as certain while in fact it is uncertain...
  
  
• Pulfrich effect
  Pulfrich effect
  The Pulfrich effect is a psychophysical percept wherein lateral motion of an object in the field of view is interpreted by the visual cortex as having a depth component, due to a relative difference in signal timings between the two eyes.-Overview:...
  
   (3D imaging) (optical illusions)
• Purkinje effect
  Purkinje effect
  The Purkinje effect is the tendency for the peak luminance sensitivity of the human eye to shift toward the blue end of the color spectrum at low illumination levels.This effect introduces a difference in color contrast under different levels of...
  
   (optical illusions) (perception) (vision)
• Pygmalion effect
  Pygmalion effect
  The Pygmalion effect, or Rosenthal effect, refers to the phenomenon in which the greater the expectation placed upon people, often children or students and employees, the better they perform...
  
   (cognitive biases)

Q

• QMR effect
  QMR effect
  Quadratic Magnetic Rotation of Polarization of Light is a type of magneto-optic effect, discovered in the mid 1980's by a team of Ukrainian physicists. QMR, like the Faraday effect, establishes a relationship between the magnetic field and rotation of polarization of the plane of linearly...
  
   (electric and magnetic fields in matter) (magnetism) (optics) (optical phenomena)
• Quantum confined stark effect (quantum mechanics)
• Quantum Hall effect (Hall effect) (condensed matter physics) (quantum electronics) (spintronics)
• Quantum Zeno effect
  Quantum Zeno effect
  The quantum Zeno effect is a name coined by George Sudarshan and Baidyanath Misra of the University of Texas in 1977 in their analysis of the situation in which an unstable particle, if observed continuously, will never decay. One can nearly "freeze" the evolution of the system by measuring it...
  
   (quantum measurement)

R

• Raman effect (physics)
• Ramp effect
  Ramp effect
  The ramp effect is a phenomenon involved in drug addiction whereby an addict develops a resistance to a substance, and thus requires increasingly large quantities of that substance to achieve the same effect...
  
   (drug addiction) (drug rehabilitation)
• Ramsauer–Townsend effect (physical phenomena) (scattering)
• Ransom note effect
  Ransom note effect
  In typography, the ransom note effect is the result of using an excessive number of juxtaposed typefaces. It takes its name from the appearance of a stereotypical ransom note, with the message formed from words or letters cut randomly from a magazine or newspaper in order to avoid using...
  
   (typography)
• Rashomon effect
  Rashomon effect
  The Rashomon effect is the effect of the subjectivity of perception on recollection, by which observers of an event are able to produce substantially different but equally plausible accounts of it. A useful demonstration of this principle in scientific understanding can be found in an article by...
  
   (psychology)
• Ratchet effect
  Ratchet effect
  A metaphorical ratchet effect is an instance of the restrained ability of human processes to be reversed once a specific thing has happened, analogous with the mechanical ratchet that holds the spring tight as a clock is wound up...
  
   (game theory)
• Rear projection effect
  Rear projection effect
  Rear projection is part of many in-camera effects cinematic techniquesin film production for combining foreground performances with pre-filmed backgrounds. It was widely used for many years in driving scenes, or to show other forms of "distant" background motion...
  
   (special effects)
• Rebound effect
  Rebound effect
  The rebound effect, or rebound phenomenon, is the tendency of some medications, when discontinued suddenly, to cause a return of the symptoms it relieved, and that, to a degree stronger than they were before treatment first began...
  
   (medical sign)
• Rebound effect (conservation)
  Rebound effect (conservation)
  In conservation and energy economics, the rebound effect refers to the behavioral or other systemic responses to the introduction of new technologies that increase the efficiency of resource use. These responses tend to offset the beneficial effects of the new technology or other measures taken...
  
   (economics paradoxes) (energy) (energy conservation)
• Red-eye effect
  Red-eye effect
  The red-eye effect in photography is the common appearance of red pupils in color photographs of eyes. It occurs when using a photographic flash very close to the camera lens , in ambient low light. The effect appears in the eyes of humans and animals that have no tapetum lucidum, hence no...
  
   (science of photography)
• Relativistic Doppler effect
  Relativistic Doppler effect
  The relativistic Doppler effect is the change in frequency of light, caused by the relative motion of the source and the observer , when taking into account effects described by the special theory of relativity.The relativistic Doppler effect is different from the non-relativistic Doppler effect...
  
   (Doppler effects) (special relativity)
• Renner–Teller effect (molecular physics)
• Reverse Cerenkov effect (physics)
• Reverse short-channel effect (transistors)
• Ringelmann effect
  Ringelmann effect
  The Ringelmann effect is the tendency for individual members of a group to become increasingly less productive as the size of their group increases...
  
   (social psychology)
• Ripple effect
  Ripple effect
  The ripple effect is a term used to describe a situation where, like the ever expanding ripples across water when an object is dropped into it, an effect from an initial state can be followed outwards incrementally....
  
   (education) (sociology)
• Robin Hood effect
  Robin Hood effect
  The Robin Hood effect is an economic occurrence where income is redistributed so that economic inequality is reduced. The effect is named after Robin Hood, said to have stolen from the rich to give to the poor.-Causes of a Robin Hood effect:...
  
   (income distribution) (Robin Hood) (socioeconomics) (taxation)
• Roe effect
  Roe effect
  The Roe effect is a theory about the long-term effect of abortion on the political balance of the United States, which suggests that since supporters of abortion rights cause the erosion of their own political base, the practice of abortion will eventually lead to the restriction or illegalization...
  
   (abortion debate) (abortion in the United States)
• Rope trick effect
  Rope trick effect
  thumb|200px|High-speed video clip of a nuclear explosion showing the rope trick effectRope trick is the term given by physicist John Malik to the curious lines and spikes which emanate from the fireball of certain nuclear explosions just after detonation....
  
   (nuclear weapons)
• Rossiter–McLaughlin effect (Doppler effects) (extrasolar planets) (spectroscopy) (star systems)
• Rusty bolt effect
  Rusty bolt effect
  The rusty bolt effect is a description of radio interference due to interactions with dirty connections or corroded parts. It is more properly known as passive intermodulation, and can result from a variety of different causes such as ferromagnetic conduction metals, nonlinear microwave absorbers...
  
   (radio electronics)

S

• Sabattier effect (solarization) (photographic processes) (science of photography)
• Sachs–Wolfe effect (astronomy) (physical cosmology)
• Sagnac effect
  Sagnac effect
  The Sagnac effect , named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called ring interferometry. A beam of light is split and the two beams are made to follow a trajectory in...
  
   (optics) (relativity)
• Samba effect
  Samba effect
  Samba effect refers to the nearly 35% drop in the value of the Brazilian real that occurred in 1999. The effect was caused by the 1997 Asian financial crisis which led Brazil to increase interest rates and to institute spending cuts and tax increases in an attempt to maintain the value of its...
  
   (Brazil) (economy of Brazil) (history of Brazil)
• Sandbox effect
  Sandbox Effect
  The Sandbox is a name given to an observation about the way Google ranks web pages in its index...
  
   (Internet technology) (search engine optimization)
• Scharnhorst effect
  Scharnhorst effect
  The Scharnhorst effect is a hypothetical phenomenon in which light signals travel faster than c between two closely spaced conducting plates. It was predicted by Klaus Scharnhorst of the Humboldt University of Berlin, Germany, and Gabriel Barton of the University of Sussex in Brighton, England...
  
   (quantum field theory)
• Schottky effect (diodes)
• Screen-door effect
  Screen-door effect
  The screen-door effect or fixed-pattern noise is a visual artifact of the projection technology used in digital projectors, where the fine lines separating the projector's pixels become visible in the projected image...
  
   (display technology) (technology)
• Second gas effect
  Second gas effect
  During induction of general anesthesia when a large volume of nitrous oxide is taken up from alveoli into pulmonary capillary blood, the concentration of gases remaining in the alveoli is increased. This results in effects known as the "concentration effect" and the "second gas effect". These...
  
   (anesthesia)
• Second-round effect
  Second-round effect
  A second-round effect means when trade unions decide to raise wages after commodity prices have increased sharply. This leads to a high inflation, so the central bank has to raise interest rates....
  
   (business) (monetary policy)
• Second-system effect
  Second-system effect
  The second-system effect refers to the tendency of small, elegant, and successful systems to have elephantine, feature-laden monstrosities as their successors. The term was first used by Fred Brooks in his classic The Mythical Man-Month...
  
   (software development)
• Seeliger effect (astronomy) (observational astronomy)
• Serial position effect
  Serial position effect
  The serial position effect, a term coined by Hermann Ebbinghaus through studies he performed on himself, refers to the finding that recall accuracy varies as a function of an item's position within a study list . When asked to recall a list of items in any order , people tend to begin recall with...
  
   (cognitive biases) (psychological theories) (psychologicy)
• Shaft effect
  Shaft effect
  The shaft effect, also known as elevator effect or shaft jacking, is a phenomenon occurring in shaft-drive motorcycles. This effect occurs because the acceleration being applied to the rear wheel creates a reactive force on the drive shaft. This in turn lifts the rider and the body of the bike,...
  
   (motorcycle)
• Shapiro effect (effects of gravitation)
• Shielding effect
  Shielding effect
  The shielding effect describes the decrease in attraction between an electron and the nucleus in any atom with more than one electron shell. It is also referred to as the screening effect or atomic shielding.-Cause:...
  
   (atomic, molecular, and optical physics) (atomic physics) (chemistry) (quantum chemistry)
• Shower-curtain effect
  Shower-curtain effect
  In physics, the shower-curtain effect is the phenomenon in which a shower curtain gets blown inward with a running shower. The problem of the cause of this effect has been featured in Scientific American magazine, with several theories given to explain the phenomenon but no definite conclusion.As a...
  
   (fluid dynamics)
• Shubnikov–de Haas effect (science)
• Side effect (computer science)
  Side effect (computer science)
  In computer science, a function or expression is said to have a side effect if, in addition to returning a value, it also modifies some state or has an observable interaction with calling functions or the outside world...
  
   (computer programming)
• Side effect
  Side effect
  In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug.Occasionally, drugs are...
  
   (disambiguation)
• Signor–Lipps effect (extinction) (fossils) (paleontology)
• Silk screen effect
  Silk screen effect
  Silk Screen Effect is a visual phenomenon seen in rear-projection televisions. SSE is described by viewers as seeing the texture of the television screen in front of the image. SSE may be found on all rear-projection televisions including DLP and Liquid Crystal on Silicon . The effect is most...
  
   (technology)
• Silo effect (management) (systems theory)
• Simon effect
  Simon effect
  In psychology, the Simon effect refers to the finding that reaction times are usually faster and more accurate when the stimulus occurs in the same relative location as the response, even if the stimulus location is irrelevant to the task. It is named for J. R. Simon who first published the effect...
  
   (psychology)
• Skin effect
  Skin effect
  Skin effect is the tendency of an alternating electric current to distribute itself within a conductor with the current density being largest near the surface of the conductor, decreasing at greater depths. In other words, the electric current flows mainly at the "skin" of the conductor, at an...
  
   (electronics)
• Slashdot effect
  Slashdot effect
  The Slashdot effect, also known as slashdotting, occurs when a popular website links to a smaller site, causing a massive increase in traffic. This overloads the smaller site, causing it to slow down or even temporarily close. The name stems from the huge influx of web traffic that results from...
  
   (denial-of-service attacks)(Internet terminology) (Slashdot)
• Sleeper effect
  Sleeper effect
  The sleeper effect is a psychological phenomenon whereby a highly persuasive message, paired with a discounting cue, causes an individual to be more persuaded by the message over time.-The sleeper effect:...
  
   (social psychology)
• Smith–Purcell effect (physics) (quantum optics)
• Snackwell effect
  Snackwell effect
  Snackwell effect is a phenomenon that states that dieters will eat more low-calorie cookies, such as SnackWells, than they otherwise would for normal cookies. The term is no longer applied simply to diet settings, as the same phenomenon is present in things like energy use. For example, according...
  
   (consumer behaviour) (psychology)
• Snob effect
  Snob effect
  The snob effect is a phenomenon often observed in the field of microeconomics that refers to the situation where the demand for a certain good for individuals of a higher income level is inversely related to the demand for the good by individuals of a lower income level...
  
   (consumer theory) (economics and finance)
• Snowball effect
  Snowball effect
  Snowball effect is a figurative term for a process that starts from an initial state of small significance and builds upon itself, becoming larger , and perhaps potentially dangerous or disastrous , though it might be beneficial instead...
  
   (language) (metaphors)
• Sound effect
  Sound effect
  For the album by The Jam, see Sound Affects.Sound effects or audio effects are artificially created or enhanced sounds, or sound processes used to emphasize artistic or other content of films, television shows, live performance, animation, video games, music, or other media...
  
   (film techniques) (sound effects) (sound production) (special effects)
• Southwest effect, The
  The Southwest effect
  The Southwest Effect is the increase in airline travel originating from a community after service to and from that community is inaugurated by Southwest Airlines or another airline that improves service or lowers cost.-Lower fares increase demand:...
  
   (airline terminology) (Southwest Airlines)
• Sow's ear effect
  Sow's ear effect
  The sow's ear effect is a term used in economics to describe when a country is unable to raise its productivity or per capita gross domestic product relative to other countries of similar development despite adjustments in macroeconomic policy, such as the exchange rate or the interest rate. This...
  
   (economics and finance) (economics effects)
• Spacing effect
  Spacing effect
  In psychology, the spacing effect refers to the fact that humans and animals more easily remember or learn items in a list when they are studied a few times over a long period of time , rather than studied repeatedly in a short period time .The phenomenon was first identified by Hermann Ebbinghaus;...
  
   (cognitive biases) (educational psychology) (psychological theories)
• Special effect
  Special effect
  The illusions used in the film, television, theatre, or entertainment industries to simulate the imagined events in a story are traditionally called special effects ....
  
   (animation) (special effects)
• Spin Hall effect (condensed matter physics) (Hall effect) (physics) (spintronics)
• Spoiler effect
  Spoiler effect
  The spoiler effect describes the effect a minor party candidate with little chance of winning has in a close election, when that candidate's presence in the election draws votes from a major candidate similar to them, thereby causing a candidate dissimilar to them to win the election...
  
   (psephology) (voting theory)
• Stark effect
  Stark effect
  The Stark effect is the shifting and splitting of spectral lines of atoms and molecules due to presence of an external static electric field. The amount of splitting and or shifting is called the Stark splitting or Stark shift. In general one distinguishes first- and second-order Stark effects...
  
   (atomic physics) (foundational quantum physics) (physical phenomena)
• Stars (shader effect)
  Stars (shader effect)
  Stars is a computer graphics effect used by computer games. The effect takes the bright parts of a rendered image of the scene, and then smears them outward in a number of directions. The result is that bright areas have streaks emanating from them. Stars can be used to enhance blooming...
  
   (3D computer graphics) (computer graphics) (demo effects)
• Status effect
  Status effect
  In role-playing games, a status effect is a temporary modification to a game character’s original set of stats that usually comes into play when special powers and abilities are used, often during combat. It appears in numerous computer and video games of many genres, most commonly in role-playing...
  
   (video game gameplay)
• Stewart–Tolman effect (electrodynamics)
• Stock sound effect (film and video technology) (film and video terminology) (film terminology)
• Storage effect
  Storage effect
  The storage effect is a coexistence mechanism proposed in the ecological theory of species coexistence, which tries to explain how such a wide variety of similar species are able to coexist within the same ecological community or guild...
  
   (demography) (population ecology)
• Stormtrooper effect
  Stormtrooper effect
  The Principle of Evil Marksmanship states that enemy marksmen in action films are often very bad shots and almost never harm the main characters. They are generally only capable of hitting a target if the target is either of no value to the plot or if their death will advance said plot...
  
   (cartoon physics) (film criticism) (humor) (plot devices) (Star Wars fandom)
• Streisand effect
  Streisand effect
  The Streisand effect is a primarily online phenomenon in which an attempt to hide or remove a piece of information has the unintended consequence of publicizing the information more widely...
  
   (dynamic lists) (eponyms) (slang)
• Stroop effect
  Stroop effect
  Purple Blue Purple----Blue Purple RedGreen Purple Green----the Stroop effect refers to the fact that naming the color of the first set of words is easier and quicker than the second....
  
   (perception) (psychological tests)
• Subadditivity effect
  Subadditivity effect
  The subadditivity effect is the tendency to judge probability of the whole to be less than the probabilities of the parts.For instance, subjects in one experiment judged the probability of death from cancer in the United States was 18%, the probability from heart attack was 22%, and the probability...
  
   (cognitive biases)
• Subject-expectancy effect
  Subject-expectancy effect
  The subject-expectancy effect, is a form of reactivity that occurs in scientific experiments or medical treatments when a research subject or patient expects a given result and therefore unconsciously affects the outcome, or reports the expected result...
  
   (cognitive biases) (psychological theories)
• Sunyaev–Zel'dovich effect (physical cosmology) (radio astronomy)
• SVG filter effect (computer graphics) (computer graphics techniques) (image processing) (Scalable Vector Graphics)
• Sylvia Plath effect
  Sylvia Plath effect
  The Sylvia Plath effect is a term coined by psychologist James C. Kaufman in 2001 to refer to the phenomenon that poets are more susceptible to mental illness than other creative writers. Kaufman's work further demonstrated that female poets were more likely to suffer from mental illness than any...
  
   (psychology)

T

• Tamagotchi effect
  Tamagotchi effect
  The Tamagotchi effect is a term that refers to the development of emotional attachment with machines or robots or even software agents. It has been noticed that humans tend to attach emotionally to things which otherwise do not have any emotions...
  
   (psychology)
• Tanada effect
  Tanada effect
  The Tanada effect refers to the adhesion of root tips to glass surfaces. It is believed to involve electric potentials. It is named for the scientist who first described the effect, Takuma Tanada, PhD, in 1968....
  
   (botany)
• Telescoping effect
  Telescoping effect
  In psychology and cognitive science, the telescoping effect is people's tendency to perceive recent events as being more remote than they are, and to perceive distant events as being more recent than they are. More specifically, the former is known as backward telescoping, and the latter as forward...
  
   (memory biases) (psychology)
• Tesla effect (wireless energy transfer) (electric power transmission systems) (electricity distribution) (energy development) (Nikola Tesla)
• Testing effect
  Testing effect
  The testing effect refers to the higher probability of recalling an item resulting from the act of retrieving the item from memory versus additional study trials of the item. However, in order for this effect to be demonstrated the test trials must have a medium to high retrieval success...
  
   (educational psychology) (memory)
• Tetris effect
  Tetris effect
  The Tetris effect occurs when people devote sufficient time and attention to an activity that it begins to overshadow their thoughts, mental images, and dreams...
  
   (memory) (Tetris)
• Thatcher effect
  Thatcher effect
  The Thatcher effect or Thatcher illusion is a phenomenon where it becomes difficult to detect local feature changes in an upside down face, despite identical changes being obvious in an upright face. It is named after British former Prime Minister Margaret Thatcher on whose photograph the effect...
  
   (vision)
• Therapeutic effect
  Therapeutic effect
  A therapeutic effect is a consequence of a medical treatment of any kind, the results of which are judged to be desirable and beneficial. This is true whether the result was expected, unexpected, or even an unintended consequence of the treatment...
  
  (medical treatment) (pharmacology)
• Thermal flywheel effect (heat) (thermodynamics)
• Thermal Hall effect
  Thermal Hall effect
  The thermal Hall effect is the thermal analog of the Hall effect. Here, a thermal gradient is produced across a solid instead of an electric field. When a magnetic field is applied, an orthogonal temperature gradient develops....
  
   (condensed matter) (Hall effect) (superconductivity)
• Third-person effect
  Third-person effect
  The third-person effect hypothesis states that a person exposed to a persuasive communication in the mass media sees it as having a greater effect on others than on himself or herself...
  
   (media studies)
• Thorpe–Ingold effect (chemical kinetics) (organic chemistry)
• Threshold effect
  Threshold effect
  Threshold effect may refer to:*Renormalization_group#Threshold_effect, a particle physics calculation* A trait in genetics...
  
   (particle physics) (physics) (renormalization group)
• Tinkerbell effect
  Tinkerbell effect
  The Tinkerbell effect is a term describing things that are thought to exist only because people believe in them. The effect is named for Tinker Bell, the fairy in the play Peter Pan who is revived from near death by the belief of the audience....
  
   (sociology)
• Training effect
  Training effect
  Training effect refers to specific changes in muscular, cardiovascular, and neurohumoral systems that lead to improvement in functional capacity and strength due to regular endurance or resistance training. It has also been defined as "an elevation of metabolism produced by exercise".Kenneth H...
  
   (cardiovascular system) (exercise physiology) (medicine) (respiratory system) (sports terminology)
• Trans effect
  Trans effect
  In inorganic chemistry, the trans effect is the labilization of ligands that are trans to certain other ligands, which can thus be regarded as trans-directing ligands...
  
   (coordination chemistry)
• Transfer effect
  Transfer effect
  The transfer effect is a term used in ornithology to describe the phenomenon observed among the bowerbirds, in which there is a continuum from physically more ornamented species which construct rudimentary bowers , to physically drabber species which construct remarkably elaborate and colorful...
  
   (ornithology)
• Transformer effect
  Transformer effect
  The transformer effect, or mutual induction, is one of the processes by which an electromotive force is induced. In a transformer, a changing electric current in a primary coil creates a changing magnetic field that induces a current in a secondary coil.This process is one of two ways of inducing...
  
   (electrodynamics)
• Transverse flow effect
  Transverse flow effect
  Transverse flow effect is an aerodynamic effect encountered when a helicopter moves through the air.In a hover, the air above the rotor disk is being pulled down from above and is equally distributed around the rotor disk...
  
   (aerodynamics)
• Trench effect
  Trench effect
  The trench effect is a combination of circumstances that can rush a fire up an inclined surface. It depends on two well-understood but separate ideas: the Coandă effect from fluid dynamics and the flashover concept from fire dynamics....
  
   (fire)
• Triboelectric effect
  Triboelectric effect
  The triboelectric effect is a type of contact electrification in which certain materials become electrically charged after they come into contact with another different material and are then separated...
  
   (electrical phenomena) (electricity)
• Trickle up effect
  Trickle up effect
  The trickle up effect is an economic theory used to describe the flow of wealth from the poor to the affluent; it is opposite to the trickle down effect.-Relationship to the trickle down effect:...
  
  
• Trickle-down effect
  Trickle-down effect
  The trickle-down effect is a marketing phenomenon that affects many consumer goods. Initially a product may be so expensive that only the wealthy can afford it...
  
   (marketing)
• Turban effect
  Turban effect
  The turban effect is a term coined in a paper published in the Journal of Experimental Social Psychology, whose lead author is Christian Unkelbach. The paper reports on a study in which Australian participants played a video game involving shooting armed characters and refraining from shooting...
  
   (anti-Islam sentiment)
• Twisted nematic field effect
  Twisted nematic field effect
  The twisted nematic effect was a main technology breakthrough that made liquid crystal displays practical. Unlike earlier displays, TN-cells did not require a current to flow for operation and used low operating voltages suitable for use with batteries...
  
   (display technology) (liquid crystal displays) (liquid crystals)
• Twomey effect
  Twomey effect
  Twomey effect — describes how cloud condensation nuclei , possibly from anthropogenic pollution, may increase the amount of solar radiation reflected by clouds. This is an indirect effect....
  
   (air pollution) (atmospheric radiation) (clouds, fog and precipitation)
• Tyndall effect
  Tyndall effect
  The Tyndall effect, also known as Tyndall scattering, is light scattering by particles in a colloid or particles in a fine suspension. It is named after the 19th century physicist John Tyndall. It is similar to Rayleigh scattering, in that the intensity of the scattered light depends on the fourth...
  
   (physical phenomena) (scattering)

U

• Umov effect
  Umov effect
  The Umov effect, also known as Umov's law, is a relationship between the albedo of an astronomical object, and the degree of polarization of light reflecting off it...
  
   (astronomy) (observational astronomy) (planetary science)
• Unruh effect
  Unruh effect
  The Unruh effect , was first described by Stephen Fulling in 1973, Paul Davies in 1975 and Bill Unruh in 1976. It is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none...
  
   (quantum field theory) (thermodynamics)
• Urban heat island effect (climate change feedbacks and causes) (climate forcing)

V

• Vandenbergh effect
  Vandenbergh effect
  The Vandenbergh effect is a phenomenon reported by J.G. Vandenbergh et al. in 1975, in which an early induction of the first estrous cycle in prepubertal female mice occurs as a result of exposure to the pheromone-laden urine of a sexually mature male mouse.Physiologically, the exposure to male...
  
   (biology)
• Vaporific effect
  Vaporific Effect
  Vaporific effect is a flash fire resulting from the impact of high velocity projectiles with metallic objects. Impacts produce particulate matter originating from either the projectile, the target, or both. Particles heated from the force of impact can burn in the presence of air...
  
   (fire)
• Veblen effect (consumer theory) (goods)
• Venturi effect
  Venturi effect
  The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe. The Venturi effect is named after Giovanni Battista Venturi , an Italian physicist.-Background:...
  
   (fluid dynamics)
• Venus effect
  Venus effect
  The Venus effect is a phenomenon in the psychology of perception, named after various paintings of Venus gazing into a mirror, such as Diego Velázquez's Rokeby Venus, Titian's Venus with a mirror, and Veronese's Venus with a mirror...
  
   (artistic techniques) (cognitive science) (film techniques) (mirrors) (psychology)
• Visual effects
  Visual effects
  Visual effects are the various processes by which imagery is created and/or manipulated outside the context of a live action shoot. Visual effects involve the integration of live-action footage and generated imagery to create environments which look realistic, but would be dangerous, costly, or...
  
   (computer generated imagery)
• Visual effects art director
  Visual effects art director
  In the context of film and television production, a visual effects art director is responsible for conceptualizing and designing visual effects shots. They are charged with making creative and aesthetic choices for visual effects. Although the role is generally more creative in nature, most...
  
  
• Voigt effect
  Voigt Effect
  The Voigt Effect, is one of a class of effects, resulting in what is called magnetic birefringence, or magnetic double refraction. It is a magneto-optical phenomenon with a similar origin to the Faraday effect. In the Faraday effect, the polarization of light can be rotated when passed through a...
  
   (magnetism) (optics)
• Von Restorff effect
  Von Restorff effect
  The Von Restorff effect , also called the isolation effect, predicts that an item that "stands out like a sore thumb" is more likely to be remembered than other items....
  
   (cognitive biases) (psychological theories)
• Vroman effect
  Vroman effect
  The Vroman effect, named after Leo Vroman, is exhibited by protein adsorption to a surface by blood serum proteins. The highest mobility proteins generally arrive first and are later replaced by less motile proteins that have a higher affinity for the surface...
  
   (molecular and cellular biology)

W

• Wagon-wheel effect
  Wagon-wheel effect
  The wagon-wheel effect is an optical illusion in which a spoked wheel appears to rotate differently from its true rotation. The wheel can appear to rotate more slowly than the true rotation, it can appear stationary, or it can appear to rotate in the opposite direction from the true rotation...
  
   (optical illusion)
• Wahlund effect
  Wahlund effect
  In population genetics, the Wahlund effect refers to reduction of heterozygosity in a population caused by subpopulation structure. Namely, if two or more subpopulations have different allele frequencies then the overall heterozygosity is reduced, even if the subpopulations themselves are in a...
  
   (evolution) (population genetics)
• Walkman effect
  Walkman effect
  The Walkman Effect refers to the way music listened to via headphones allows the user to gain more control over their environment. It was coined by International Research Center for Japanese Studies Professor Shuhei Hosokawa in an article of the same name published in Popular Music in 1984...
  
   (computing and society) (technology)
• Wallace effect
  Wallace effect
  The Wallace Effect is a hypothesis developed by British naturalist Alfred Russel Wallace which posits that natural selection can contribute to the reproductive isolation of incipient species by encouraging varieties to develop barriers to hybridization....
  
   (evolutionary biology) (speciation)
• Warburg effect
  Warburg effect
  The phrase "Warburg effect" is used for two unrelated observations in biochemistry, one in plant physiology and the other in oncology, both due to Nobel laureate Otto Heinrich Warburg.-Plant physiology:...
  
   (biochemistry) (oncology) (photosynthesis)
• Wealth effect
  Wealth effect
  The wealth effect is an economic term, referring to an increase in spending that accompanies an increase in perceived wealth.-Effect on individuals:...
  
   (economics and finance) (wealth)
• Weapons effect
  Weapons Effect
  The weapons effect is a finding in studies of aggression suggesting that the mere presence of a weapon, words describing weapons, or pictures of weapons, may facilitate an increased likelihood of aggression, especially among angered persons....
  
   (gun politics)
• Weathervane effect
  Weathervane effect
  Weathervaning or weathercocking is a phenomenon experienced by aircraft on the ground.Aircraft on the ground have a natural pivoting point on an axis through the main landing gear contact points [disregarding the effects of toe in/toe out of the main gear]...
  
   (aviation terminology)
• Weissenberg effect
  Weissenberg effect
  The Weissenberg effect is a common phenomenon that occurs when a spinning rod is placed into a solution of liquid polymer. Instead of being thrown outward, entanglements cause the polymer chains to be drawn towards the rod. It is named after Karl Weissenberg....
  
   (physics)
• Wet floor effect
  Wet floor effect
  Wet floor effect is a graphic effects technique popular in conjunction Web 2.0 style pages, particularly in logos. The effect can be done manually or an auxiliary tool can be installed to create the effect automatically...
  
   (computer graphic techniques) (computer graphics) (Web 2.0)
• Whitten effect
  Whitten effect
  The Whitten effect is a phenomenon observed by Wesley K. Whitten , whereby male mouse pheromone-laden urine synchronizes the estrus cycle "among unisexually grouped females."...
  
   (menstruation)
• Wigner effect
  Wigner effect
  The Wigner effect , also known as the discomposition effect, is the displacement of atoms in a solid caused by neutron radiation....
  
   (condensed matter physics) (nuclear technology) (physical phenomena) (radiation effects)
• Wilson effect
  Wilson effect
  In 1769 a Scottish astronomer named Alexander Wilson, working at the Macfarlane Observatory, noticed that the shape of sunspots noticeably flattened as they approached the Sun's limb due to the solar rotation. These observations showed that sunspots were features on the solar surface, as opposed to...
  
   (astronomy) (Sun)
• Wilson–Bappu effect (physics)
• Wimbledon effect
  Wimbledon Effect
  The Wimbledon Effect is a chiefly British and Japanese analogy which compares the tennis fame of the Wimbledon Championships, held at the All England Lawn Tennis and Croquet Club in Wimbledon, London, with the economic success of the United Kingdom's financial services industries — especially...
  
   (economic theories) (economy of Japan) (economy of London)
• Windkessel effect
  Windkessel effect
  Windkessel effect is a term used in medicine to account for the shape of the arterial pressure waveform in terms of the interaction between the stroke volume and the compliance of the aorta and large elastic arteries . Windkessel in German literally means 'air chamber', but is generally taken to...
  
   (physiology)
• Withgott effect
  Withgott Effect
  The Withgott effect is a term in the study of Phonology relating to the pronunciation of stops in American English.Speakers of American English pronounce the sound [t] in characteristic but complex ways...
  
   (linguistics) (phonetics)
• Wolf effect
  Wolf effect
  The Wolf Effect is a frequency shift in the electromagnetic spectrum.The phenomenon occurs in several closely related phenomena in radiation physics, with analogous effects occurring in the scattering of light. It was first predicted by Emil Wolf in 1987 and subsequently confirmed in the...
  
   (scattering) (spectroscopy)
• Wolff–Chaikoff effect (iodine) (medicine)
• Woodward effect
  Woodward effect
  The Woodward effect is a hypothesis proposed by James F. Woodward, a physicist at California State University, Fullerton, that energy-storing ions experience transient mass fluctuations when accelerated. While some have expressed doubt about this hypothesis, no respected theoreticians have yet...
  
   (propulsion)
• Word superiority effect
  Word Superiority effect
  In cognitive psychology, the word superiority effect refers to the phenomenon that people are more accurate in recognizing a letter in the context of a word than they are when a letter is presented in isolation, or when a letter is presented within a nonword...
  
   (cognitive science)
• Worse-than-average effect
  Worse-than-average effect
  The worse-than-average effect or below-average effect is the human tendency to underestimate one's achievements and capabilities in relation to others....
  
   (cognitive biases) (psychological theories) (social psychology)

Y

• Yarkovsky effect
  Yarkovsky effect
  The Yarkovsky effect is a force acting on a rotating body in space caused by the anisotropic emission of thermal photons, which carry momentum...
  
   (celestial mechanics)
• Yarkovsky–O'Keefe–Radzievskii–Paddack effect (celestial mechanics)

Z

• Zeeman effect
  Zeeman effect
  The Zeeman effect is the splitting of a spectral line into several components in the presence of a static magnetic field. It is analogous to the Stark effect, the splitting of a spectral line into several components in the presence of an electric field...
  
   (atomic physics) (foundational quantum physics) (magnetism) (physical phenomena)
• Zeigarnik effect (cognitive biases) (educational psychology) (learning) (psychological theories)