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Square root of 2
The square root of 2, sometimes called Pythagoras's constant, is the positive real number that multiplies by itself to give 2, about 1.4142135, and cannot be written as a ratio of two integers.
Square root of 3
The square root of 3, also called Theodorus's constant, is the irrational number whose square is 3, approximately 1.7320508, giving side ratios in the 30-60-90 triangle.
Square root of 5
The square root of 5 is the positive real number whose square is 5, an irrational number, and it links the regular pentagon to the golden ratio.
Square root of a matrix
A square root of a matrix is a matrix B whose square B² equals the given matrix A. Roots may not exist and are generally not unique.
Square with sculptures
Square with sculptures (Сквер з скульптурами) is a 24/7 public park on Prymorska Street 6А in Zatoka, Odesa Oblast, Ukraine, with shade trees, benches, and photo sculptures near the Zatoka Lift Bridge.
Square-free integer
A square-free integer, also called a squarefree number, is an integer not divisible by any perfect square greater than 1; examples include 6 and 30, while 12 is not.
Square-integrable function
A square-integrable function, or L2 function, is a function whose absolute value squared has a finite Lebesgue integral; such functions form the Hilbert space L2.
Square-root information filter
The square-root information filter (SRIF) is a state-estimation algorithm equivalent to the Kalman filter but numerically more stable, developed by Gerald J. Bierman at JPL.
Square-wave voltammetry
Square-wave voltammetry (SWV), also known as Osteryoung square-wave voltammetry, is a fast, highly sensitive electroanalytical technique that superimposes a square wave on a staircase ramp, giving peak currents proportional to concentration.
Square–cube law
The square–cube law states that when an object is scaled up, surface area grows as k² and volume as k³, first described by Galileo in 1638.
Squarefree word
A squarefree word is a string of symbols containing no immediately repeated block, such as cocoa; Thue showed in 1906 that arbitrarily long ones exist over three letters.
Squarepoint Capital
Squarepoint Capital, also known as Squarepoint Ops, is a partner-owned global quantitative investment manager formed in 2014 from Barclays' systematic trading business, managing about $227 billion.
Squarepusher
Squarepusher is Tom Jenkinson, Chelmsford-born English electronic musician and virtuoso bassist on Warp Records; drill'n'bass and jazz fusion albums from Feed Me Weird Things (1996) to Kammerkonzert (2026), distinct from Aphex Twin.
Squarespace
Squarespace is an all-in-one software-as-a-service platform for building and hosting websites, offering templates, e-commerce, and domains, founded by Anthony Casalena and taken private by Permira in 2024 for about $7.2 billion.
Squaric acid
Squaric acid (3,4-dihydroxycyclobut-3-ene-1,2-dione) is a four-membered ring carbon oxoacid first synthesized in 1959, whose resonance-stabilized squarate dianion gives it acidity close to sulfuric acid and whose derivatives serve in dyes, catalysis, and medicinal chemistry.
Squaring the circle
Squaring the circle, also called quadrature of the circle, is the classical problem of constructing a square equal in area to a circle with compass and straightedge.
Squark
A squark is the hypothetical spin-0 superpartner of a quark predicted by supersymmetry; LHC searches have found no squarks, excluding masses up to about 1.85 TeV.
Squash (drink)
Squash, also known as cordial or diluting juice, is a concentrated fruit drink diluted with water before drinking, and a staple household beverage in the United Kingdom, Ireland, and Commonwealth countries.
Squash (sport)
Squash: indoor racket sport, born at Harrow School c. 1830 from a punctured rackets ball; 9.75 x 6.40 m enclosed court, ball to 11 scoring, Olympic debut at LA28.
Squash at the 2028 Summer Olympics
Squash at the 2028 Summer Olympics (LA28): the sport's Olympic debut with men's and women's singles, 16-player draws, 32 athletes, at the Comcast Squash Center, Universal Studios, July 15-24, 2028.
Squashed entanglement
Squashed entanglement, also called CMI entanglement, is an entanglement measure for bipartite quantum states, defined via the quantum conditional mutual information and introduced by Christandl and Winter in 2003.
Squat (exercise)
Squat (exercise): compound lower-body resistance exercise flexing hips, knees, and ankles; works quadriceps, glutes, hamstrings. Variants include back, front, goblet, and chair squats; deep squats are safe with proper technique.
Squat effect
The squat effect is the drop in a ship's under-keel clearance when moving through shallow or restricted water, caused by low pressure beneath the hull and increasing with speed.
Squat lobster
Squat lobster, anomuran decapod crustacean (superfamilies Chirostyloidea and Galatheoidea) related to hermit crabs, not true lobsters; Late Triassic fossil record, deep-sea habitats, Latin American fisheries.
Squat toilet
A squat toilet, also called a Turkish or Indian toilet, is a toilet used in a squatting posture, common across much of Asia, Africa, and the Middle East.
Squatting
Squatting, also called adverse possession, is occupying property without permission. Covers criminal law in England and Wales, adverse possession requirements, Roman origins, homelessness links, and comparative legal responses.
Squatting position
Squatting position: a resting, working, toileting, and exercise posture with deeply flexed knees and hips; used by at least a fourth of humanity, defined by knee flexion angles, and reviewed for knee safety.
Squaw
Squaw: English word for a Native American woman, from Algonquian (Massachusett squa) 'woman', 1630s; now a slur for Indigenous women. Removed from about 650 US federal place names by Secretarial Order 3404 and Board on Geographic Names votes in 2022-2023.
Squawk code
A squawk code is a four-digit transponder number a pilot enters so air traffic control radar can identify the aircraft, with 7500, 7600, and 7700 reserved for emergencies.
Squeak (programming language)
Squeak, also known as Squeak Smalltalk, is an open-source Smalltalk programming system created at Apple Computer in 1996 by Alan Kay, Dan Ingalls, and Ted Kaehler, known for its self-hosting virtual machine written in Smalltalk.