Alpha

Alpha /ˈælfə/^[1] (uppercase Α, lowercase α; Ancient Greek: ἄλφα, álpha, modern pronunciation álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , which is the West Semitic word for "ox".^[2] Letters that arose from alpha include the Latin letter A and the Cyrillic letter А.

Uses

Greek

In Ancient Greek, alpha was pronounced [a] and could be either phonemically long ([aː]) or short ([a]). Where there is ambiguity, long and short alpha are sometimes written with a macron and breve today: Ᾱᾱ, Ᾰᾰ.

ὥρα = ὥρᾱ hōrā Greek pronunciation: [hɔ́ːraː] "a time"
γλῶσσα = γλῶσσᾰ glôssa Greek pronunciation: [ɡlɔ̂ːssa] "tongue"

In Modern Greek, vowel length has been lost, and all instances of alpha simply represent IPA: [a].

In the polytonic orthography of Greek, alpha, like other vowel letters, can occur with several diacritic marks: any of three accent symbols (ά, ὰ, ᾶ), and either of two breathing marks (ἁ, ἀ), as well as combinations of these. It can also combine with the iota subscript (ᾳ).

Greek grammar

In the Attic–Ionic dialect of Ancient Greek, long alpha [aː] fronted to [ɛː] (eta). In Ionic, the shift took place in all positions. In Attic, the shift did not take place after epsilon, iota, and rho (ε, ι, ρ; e, i, r). In Doric and Aeolic, long alpha is preserved in all positions.^[3]

Doric, Aeolic, Attic χώρᾱ chṓrā — Ionic χώρη chṓrē, "country"
Doric, Aeolic φᾱ́μᾱ phā́mā — Attic, Ionic φήμη phḗmē, "report"

Privative a is the Ancient Greek prefix ἀ- or ἀν- a-, an-, added to words to negate them. It originates from the Proto-Indo-European *n̥- (syllabic nasal) and is cognate with English un-.

Copulative a is the Greek prefix ἁ- or ἀ- ha-, a-. It comes from Proto-Indo-European *sm̥.

Mathematics and science

The letter alpha represents various concepts in physics and chemistry, including alpha radiation, angular acceleration, alpha particles, alpha carbon and strength of electromagnetic interaction (as Fine-structure constant). Alpha also stands for thermal expansion coefficient of a compound in physical chemistry. It is also commonly used in mathematics in algebraic solutions representing quantities such as angles. Furthermore, in mathematics, the letter alpha is used to denote the area underneath a normal curve in statistics to denote significance level^[4] when proving null and alternative hypotheses. In ethology, it is used to name the dominant individual in a group of animals. In aerodynamics, the letter is used as a symbol for the angle of attack of an aircraft and the word "alpha" is used as a synonym for this property. In mathematical logic, α is sometimes used as a placeholder for ordinal numbers.

The proportionality operator "∝" (in Unicode: U+221D) is sometimes mistaken for alpha.

The uppercase letter alpha is not generally used as a symbol because it tends to be rendered identically to the uppercase Latin A.

International Phonetic Alphabet

In the International Phonetic Alphabet, the letter ɑ, which looks similar to the lower-case alpha, represents the open back unrounded vowel.

History and symbolism

Origin

The Phoenician alphabet was adopted for Greek in the early 8th century BC, perhaps in Euboea.^[5] The majority of the letters of the Phoenician alphabet were adopted into Greek with much the same sounds as they had had in Phoenician, but ʼāleph, the Phoenician letter representing the glottal stop [ʔ], was adopted as representing the vowel [a]; similarly, hē [h] and ʽayin [ʕ] are Phoenician consonants that became Greek vowels, epsilon [e] and omicron [o], respectively.

Plutarch

Plutarch, in Moralia,^[6] presents a discussion on why the letter alpha stands first in the alphabet. Ammonius asks Plutarch what he, being a Boeotian, has to say for Cadmus, the Phoenician who reputedly settled in Thebes and introduced the alphabet to Greece, placing alpha first because it is the Phoenician name for ox—which, unlike Hesiod,^[7] the Phoenicians considered not the second or third, but the first of all necessities. "Nothing at all," Plutarch replied. He then added that he would rather be assisted by Lamprias, his own grandfather, than by Dionysus' grandfather, i.e. Cadmus. For Lamprias had said that the first articulate sound made is "alpha", because it is very plain and simple—the air coming off the mouth does not require any motion of the tongue—and therefore this is the first sound that children make.

According to Plutarch's natural order of attribution of the vowels to the planets, alpha was connected with the Moon.

Alpha and Omega

Memorial Stained Glass window, Royal Military College of Canada features Alpha and Omega

As the first letter of the alphabet, Alpha as a Greek numeral came to represent the number 1. Therefore, Alpha, both as a symbol and term, is used to refer to the "first", or "primary", or "principal" (most significant) occurrence or status of a thing.

The New Testament has God declaring himself to be the "Alpha and Omega, the beginning and the end, the first and the last." (Revelation 22:13, KJV, and see also 1:8).^{[non-primary source needed]}

Consequently, the term "alpha" has also come to be used to denote "primary" position in social hierarchy, examples being "alpha males" or pack leaders.

Computer encodings

Greek alpha / Coptic alfa^[8]

Character information
Preview	Α		α		Ⲁ		ⲁ
Unicode name	GREEK CAPITAL LETTER ALPHA		GREEK SMALL LETTER ALPHA		COPTIC CAPITAL LETTER ALFA		COPTIC SMALL LETTER ALFA
Encodings	decimal	hex	decimal	hex	decimal	hex	decimal	hex
Unicode	913	U+0391	945	U+03B1	11392	U+2C80	11393	U+2C81
UTF-8	206 145	CE 91	206 177	CE B1	226 178 128	E2 B2 80	226 178 129	E2 B2 81
Numeric character reference	Α	Α	α	α	Ⲁ	Ⲁ	ⲁ	ⲁ
Named character reference	Α		α
CP 437			224	E0
DOS Greek	128	80	152	98
DOS Greek-2	164	A4	214	D6
Windows 1253	193	C1	225	E1
TeX			\alpha

For accented Greek characters, see Greek diacritics: Computer encoding.

Latin / IPA alpha

Character information
Preview	ɑ		ɒ		ᶐ		ᵅ		ᶛ
Unicode name	LATIN SMALL LETTER ALPHA		LATIN SMALL LETTER TURNED ALPHA		LATIN SMALL LETTER ALPHA WITH RETROFLEX HOOK		MODIFIER LETTER SMALL ALPHA		MODIFIER LETTER SMALL TURNED ALPHA
Encodings	decimal	hex	decimal	hex	decimal	hex	decimal	hex	decimal	hex
Unicode	593	U+0251	594	U+0252	7568	U+1D90	7493	U+1D45	7579	U+1D9B
UTF-8	201 145	C9 91	201 146	C9 92	225 182 144	E1 B6 90	225 181 133	E1 B5 85	225 182 155	E1 B6 9B
Numeric character reference	ɑ	ɑ	ɒ	ɒ	ᶐ	ᶐ	ᵅ	ᵅ	ᶛ	ᶛ

Mathematical / Technical alpha

Character information
Preview	⍺		⍶		WIKI

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