All articles starting with R

Redshift drift

Redshift drift is the tiny, systematic change over time in a distant object's cosmological redshift caused by the universe's expansion, proposed by Allan Sandage in 1962.

Redshift estimation is the astronomical method of measuring how much an object's light is shifted to longer wavelengths, done spectroscopically or photometrically, with spectroscopy far more accurate.

Redshift survey

A redshift survey is an observational astronomy method that measures redshifts of a large, well-defined galaxy sample and uses them as distance proxies to map three-dimensional cosmic structure.

Redshift-space distortions

Redshift-space distortions (RSD) are anisotropic distortions of the observed galaxy distribution arising from peculiar velocities: the Kaiser effect on large scales and Fingers of God in clusters.

Redshirt (college sports)

Redshirt (college sports): an NCAA athlete held out of varsity competition for a year to extend eligibility under the Five-Year Rule (four seasons in five years); football allowed four games per redshirt year, and the June 2026 age-based eligibility model eliminated redshirt rules.

Redskin

Redskin is an English slur for a Native American; originally a self-referential term (1769, via French peau-rouge), it became pejorative, drew trademark cancellations against Washington's NFL team, and was retired by the franchise in 2020.

Redstar Wu & the Worldwide Scourge

Redstar Wu & the Worldwide Scourge is the third studio album by Ghanaian-Australian artist Genesis Owusu (Kofi Owusu-Ansah), released May 15, 2026 on Ourness; a 14-track, 50-minute political genre-blender produced by Dann Hume, scoring 88 on Metacritic.

Oct 21, 2026

Redstone

Redstone is a 2012 two-player Go variant by Mark Steere in which captures must be made with permanent, uncapturable red stones; the goal is annihilation of all enemy stones, with no passing, no draws, and the pie rule instead of komi.

Redstone Arsenal

Redstone Arsenal, a ~38,000-acre U.S. Army installation near Huntsville, Alabama, hosts 75+ tenant agencies including AMCOM, AMC, SMDC, MDA, NASA Marshall, and the FBI; ~45,500 workers, $36.2 billion impact.

Redstone Digital

Redstone Digital, also known as Redstone VC, is a Berlin-based early-stage venture capital firm founded in 2014 by Michael Brehm and Samuli Sirén, with roughly €600 million under management.

Redstone Solar Thermal Power Project

The Redstone Solar Thermal Power Project is a 100 MW concentrated solar power plant with 12 hours of molten salt storage near Postmasburg, South Africa, developed by ACWA Power.

RedTube

RedTube is a free adult video sharing website opened in 2007 as one of the early YouTube-style tube sites, now operated by Cyprus-based Aylo Freesites Ltd, a sister site of Pornhub and YouPorn.

Reduce (computer algebra system)

REDUCE is a portable, general-purpose computer algebra system begun by Anthony C. Hearn at Stanford in 1963 for physics calculations, and free, open-source software under a modified BSD license since 2008.

Oct 20, 2026

REDUCE-IT trial

REDUCE-IT (NCT01492361): 8,179-patient randomized trial of icosapent ethyl 4 g/day purified EPA versus mineral oil placebo in statin-treated patients with elevated triglycerides; 25% relative MACE reduction, mineral oil placebo controversy, contrast with null STRENGTH trial.

Reduced affect display

Reduced affect display, also called blunted affect or emotional blunting, is diminished outward emotional expression through face, voice, and gestures. It affects about 30% of people with schizophrenia, is a negative symptom, and is rated with instruments such as the BNSS, CAINS, and SANS.

Reduced basis method

The reduced basis method, also known as reduced basis, is a model order reduction technique for parametrized partial differential equations, first introduced in the late 1970s.

Reduced density matrix

A reduced density matrix describes the state of a quantum subsystem of a larger system, obtained by the partial trace, and is the standard tool for quantifying entanglement.

Oct 21, 2026

Reduced folate carrier

Reduced folate carrier (RFC, SLC19A1), also RFC-1, is a ubiquitously expressed MFS anion-exchanger importing reduced folates and antifolate drugs like methotrexate; its loss causes antifolate drug resistance.

Reduced graphene oxide

Reduced graphene oxide (rGO), or chemically reduced graphene oxide (CReGO), is a graphene-like material produced by removing oxygen groups to restore electrical conductivity for use in sensors and electronics.

Reduced instruction set computer

A reduced instruction set computer (RISC), or RISC processor, is a microprocessor architecture built on a small set of simple, one-cycle instructions, arising from IBM research in the late 1970s.

Reduced mass

Reduced mass is the effective mass μ = m₁m₂/(m₁+m₂), always smaller than either body, that reduces a two-body problem to one-body motion; it enters atomic spectra and rotational spectroscopy.

Reduced representation bisulfite sequencing

Reduced representation bisulfite sequencing (RRBS) is a method measuring DNA methylation at single-base resolution across CpG-rich regions, using MspI digestion to cut sequencing costs about tenfold.

Reduced ring

A reduced ring is a ring containing no nonzero nilpotent elements, so x squared equaling zero forces x to be zero; examples include every integral domain and Boolean ring.

Reduced shear

Reduced shear, g = γ/(1−κ), is the quantity actually measured in weak gravitational lensing, since galaxy ellipticities respond to it rather than to the shear alone.

Reduced vertical separation minima

Reduced vertical separation minima (RVSM) is an aviation standard that reduces the vertical separation between aircraft from 2,000 to 1,000 feet between flight levels 290 and 410.

Reduced word

A reduced word, also called a reduced expression, is a shortest expression for an element of a Coxeter group as a product of simple reflections, with its common length the element's length.

Reduced-gravity aircraft

A reduced-gravity aircraft, nicknamed the Vomit Comet, flies steep parabolic arcs giving passengers about 20 seconds of weightlessness, used by space agencies to train astronauts and test equipment.

Reduced-intensity conditioning

Reduced-intensity conditioning (RIC) is a lower-dose preparative regimen for allogeneic hematopoietic stem cell transplantation that relies on donor immune effects rather than marrow eradication, developed in the late 1990s for older patients and those with comorbidities.

Oct 20, 2026

Reduced-mineral goat whey

Reduced-mineral goat whey (RMGW), a demineralized goat cheese whey powder, GRAS Notice 1211 by Crossway Foods; FDA no-questions letter Feb 4, 2025 for infant formula use up to 40% dry weight.