Beta (, ; uppercase , lowercase , or cursive Greek ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represents the voiced labiodental fricative , while in borrowed words is instead commonly transcribed as μπ.
Name
Like the names of most other Greek letters, the name of beta comes from the
acrophony name of the corresponding letter in Phoenician, which was the common Semitic word *bayt ('house', compare bayt and báyit). In Greek, the name was βῆτα bêta, pronounced in Ancient Greek. It is spelled βήτα in modern monotonic orthography and pronounced .
History
The letter beta was derived from the Phoenician letter beth .
The letter Β had the largest number of highly divergent local forms. Besides the standard form (either rounded or pointed, ), there were forms as varied as (Gortyn), and (Thera), (Argos), (Melos), (Ancient Corinth), (Megara, Byzantium), and (Cyclades).
Typography
In some high-quality typesetting, especially in the French tradition, a typographic variant of the lowercase letter without a
descender is used within a word for
ancient Greek: is printed .
In typesetting technical literature, it is a commonly made mistake to use the German letter ß (a s–z or s–s ligature) as a replacement for β. The two letters resemble each other in some fonts, but they are unrelated.
Uses
Algebraic numerals
In the system of
Greek numerals, beta has a value of 2. Such use is denoted by a number mark: Β′.
Computing
Finance
Beta is used in finance as a measure of investment portfolio risk.
International Phonetic Alphabet
In the International Phonetic Alphabet, Greek minuscule beta denotes a voiced bilabial fricative .
A superscript version may also indicate a compressed vowel, like .
Meteorology
Beta has twice been used to name an Atlantic Basin
tropical cyclone:
Mathematics and science
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Beta is often used to denote a variable in mathematics and physics, where it often has specific meanings for certain applications.
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Some uses of beta in math include:
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β is sometimes used as a placeholder for an ordinal number if α is already used. For example, the two roots of a quadratic equation are typically labelled and .
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In regression analysis, symbolizes nonstandardized partial slope coefficients, whereas represents standardized (standard deviation-score form) coefficients; in both cases, the coefficients reflect the change in the criterion Y per one-unit change in the value of the associated predictor X.
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In statistics, beta may represent type II error,
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Dirichlet beta function
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Some uses of beta in physics and engineering include:
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In spaceflight, beta angle describes the angle between the orbit plane of a spacecraft or other body and the vector from the sun.
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In nuclear physics, β is used for a beta particle (an unbound energetic electron or positron).
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In statistical thermodynamics, a quantity known as thermodynamic beta expresses how the entropy of system responds to a small increase in temperature.
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β is also used for naming in biology. For example, e.g. Beta-Carotene, a primary source of provitamin Vitamin A; Β Cells in pancreatic islets, which produce insulin; and beta sheet, a common motif in protein secondary structure.
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The uppercase letter beta is not generally used as a symbol because it tends to be rendered identically to the uppercase Latin B.
Rock climbing terminology
The term "beta" refers to advice on how to successfully complete a particular climbing route, boulder problem, or crux sequence.
Slang
Beta male, or simply
beta, is a slang term for men derived from the designation for beta animals in ethology, along with its counterpart,
alpha male. The term has been used as a pejorative self-identifier among members of
manosphere communities, particularly
, who do not believe they are assertive or traditionally
masculine, and feel overlooked by women.
It is also used to negatively describe other men who are not assertive, particularly in
heterosexual relationships.
Videotape formats
"Beta" can be used to refer to several consumer and professional videotape formats developed by Japan's
Sony. Although similarly named, they are very different in function and obsolescence.
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Betamax was the name of a domestic videotape format developed in the 1970s and 1980s. It competed with the Video Home System (VHS) format developed by the JVC, to which it eventually succumbed. The Betamax format was also marketed Betacord by (Sanyo); some cassettes were simply labeled "Beta", and the logo was a lower-case beta. Betamax lost in the market and is an oft-used example of a technically superior solution that failed due to market forces.
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Betacam, including Beta SP and DigiBeta, is a family of professional videotape formats launched in 1982 that was the de facto standard for professional video, advertising, and television production through the 2000s. The formats outlasted analog NTSC television, and their scarcity today is because the industry has moved to HD formats.
Unicode
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( in TeX)
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(Japanese square katakana of ベータ )
These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style:
