All articles starting with R

Reverse mathematics

Reverse mathematics, also known as reverse math, is a program in mathematical logic founded by Harvey Friedman in 1974 that determines which axioms are necessary to prove theorems of ordinary mathematics.

Reverse Monte Carlo

Reverse Monte Carlo (RMC) is a modeling technique that adjusts atomic positions until calculated scattering matches measured diffraction data, introduced by McGreevy and Pusztai in 1988.

Reverse mortgage

A reverse mortgage is a loan against home equity that pays cash to an older homeowner with no monthly repayment; the balance grows until death, sale, or move-out.

Reverse osmosis

Reverse osmosis is a water purification process in which pressure drives water through a semipermeable membrane while dissolved salts are retained. It is the dominant technology for seawater desalination.

Reverse phase protein array

Reverse phase protein array (RPPA) is a targeted proteomics method that spots many samples as microdots on slides and probes them one antibody at a time.

Reverse Polish notation

Reverse Polish notation, also called postfix notation, writes operators after their operands, so no parentheses or precedence rules are needed; 1 + 2 becomes 1 2 +.

Reverse proxy

A reverse proxy is a server that sits in front of origin servers, receives client requests as if it were the origin, and forwards them to servers behind it.

Reverse psychology

Reverse psychology, formally strategic self-anticonformity, is a social influence tactic advocating the opposite of what one wants; it works through Brehm's psychological reactance, whose message triggers and persuasion effects are quantified by the 2025 Li and Shi meta-analysis.

Reverse racism

Reverse racism: alleged prejudice or discrimination against majority or historically dominant groups, especially white people, tied to affirmative action and DEI debates; distinct from the legal term reverse discrimination and contested over whether racism requires power.

Reverse sneezing

Reverse sneezing (paroxysmal respiration) is a nasopharyngeal irritation reflex in dogs and cats causing rapid, loud inward inhalations with extended neck; usually benign, common in small and brachycephalic dogs, often idiopathic.

Reverse telephone directory

A reverse telephone directory, also known as a gray pages directory or criss-cross directory, indexes listings by phone number or address so users can find who owns a number.

Reverse time migration

Reverse time migration (RTM) is a seismic imaging method that propagates recorded wavefields backward in time using the full two-way wave equation, introduced in the early 1980s.

Reverse transcriptase

Reverse transcriptase is a DNA polymerase that copies RNA into DNA, the reverse of transcription; discovered in 1970, it is a key drug target in HIV treatment.

Oct 21, 2026

Reverse Transcription

Reverse transcription is the process using reverse transcriptase to synthesize DNA from an RNA template. It was independently discovered in 1970 by Howard Temin and David Baltimore.

Reverse transcription loop-mediated isothermal amplification

Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a one-step nucleic acid test that converts RNA to DNA and amplifies it at a single constant temperature.

Reverse transcription polymerase chain reaction

Reverse transcription polymerase chain reaction (RT-PCR) is a laboratory method that converts RNA into DNA and amplifies it, used to detect RNA viruses like SARS-CoV-2.

Reverse transcription recombinase polymerase amplification

Reverse transcription recombinase polymerase amplification (RT-RPA) is an isothermal nucleic acid amplification method that converts RNA to cDNA and amplifies it at a constant 37–42 °C.

Reverse vaccinology

Reverse vaccinology is a bioinformatics method for vaccine development that screens a pathogen's genome sequence in silico to select candidate protein antigens, without culturing the pathogen.

Reverse water-gas shift reaction

The reverse water-gas shift reaction (RWGS) is the endothermic reaction converting carbon dioxide and hydrogen into carbon monoxide and water, a key step in producing fuels and chemicals from CO₂.

Reverse zoonosis

Reverse zoonosis, also called zooanthroponosis or anthroponotic transmission, is the transmission of pathogens from humans to animals, including wildlife, livestock, and pets; SARS-CoV-2 has spread from humans to deer, mink, and zoo animals.

Oct 22, 2026

Reverse-bias degradation of perovskite solar cells

Reverse-bias degradation is the efficiency loss perovskite solar cells suffer under negative voltage, typically when partial shading drives a cell in a series module below zero volts.

Reverse-conducting IGBT

A reverse-conducting IGBT (RC-IGBT) is a power semiconductor device that combines an IGBT and a freewheeling diode on one silicon chip, saving over 30% of the area.

Reverse-Flash

Reverse-Flash is the DC Comics speedster villain Eobard Thawne, also called Professor Zoom, the archenemy of Barry Allen's Flash. Debuted in The Flash #139 (1963) by Broome and Infantino; creator of the Negative Speed Force; succeeded at times by Zoom/Hunter Zolomon and Daniel West.

Reversed field pinch

The reversed field pinch (RFP) is a toroidal magnetic confinement configuration for fusion plasma in which the toroidal field reverses in the outer plasma region, third-most developed after the tokamak and stellarator.

Reversed glottal stop

The reversed glottal stop is the IPA symbol ʕ, a glottal stop turned to open leftward, which transcribes the voiced pharyngeal fricative, the Arabic sound ʿayn.

Reversed-phase chromatography

Reversed-phase chromatography (RPC), also called reversed-phase liquid chromatography (RPLC), is the most widely used liquid chromatography mode, with mobile phase more polar than its nonpolar C8 or C18 stationary phase.

Reversi

Reversi, also known as Othello (オセロ), is an 8×8 two-player disc-flipping board game invented in 1883 England by Waterman and Mollett and standardized as Othello by Goro Hasegawa in Japan in 1971; Black moves first, corners are permanent, and the World Othello Championship runs since 1977.

Oct 22, 2026

Reversibility transition in cyclically driven glasses

The reversibility transition is the sharp change in a cyclically sheared glass between repeating particle trajectories and diffusive, chaotic motion at a critical strain amplitude.

Reversible addition−fragmentation chain-transfer polymerization

RAFT polymerization is a form of controlled radical polymerization, first reported at CSIRO in Australia in 1998, giving polymers with predictable molecular weights and low dispersity.