Alpha

For other uses, see Alpha (disambiguation).

Greek alphabet
Αα	Alpha	Νν	Nu
Ββ	Beta	Ξξ	Xi
Γγ	Gamma	Οο	Omicron
Δδ	Delta	Ππ	Pi
Εε	Epsilon	Ρρ	Rho
Ζζ	Zeta	Σσς	Sigma
Ηη	Eta	Ττ	Tau
Θθ	Theta	Υυ	Upsilon
Ιι	Iota	Φφ	Phi
Κκ	Kappa	Χχ	Chi
Λλ	Lambda	Ψψ	Psi
Μμ	Mu	Ωω	Omega
History
Archaic local variants
Ligatures (ϛ, ȣ, ϗ) Diacritics
Numerals ϛ (6) ϟ (90) ϡ (900)
In other languages
Bactrian Coptic Albanian
Scientific symbols
Book Category Commons

Alpha (uppercase Α, lowercase α; Greek: Άλφα Álpha) is the first letter of the Greek alphabet. In the system of Greek numerals it has a value of 1. It was derived from the Phoenician letter aleph . Letters that arose from alpha include the Latin A and the Cyrillic letter А.

In English, the noun "alpha" is used as a synonym for "beginning", or "first" (in a series), reflecting its Greek roots.

Uses

Greek

In Ancient Greek, alpha was pronounced [a] when short and [aː] when long. Where there is ambiguity, long and short alpha are sometimes written with a macron and breve today: Ᾱᾱ, Ᾰᾰ.

• ὥρα = ὥρᾱ hōrā [hɔ̌ːraː] "a time"
• γλῶσσα = γλῶσσᾰ glôssa [ɡlɔ̂ːssa] "tongue"

In Modern Greek, vowel length has been lost, and all instances of alpha represent the short [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.

• 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.

Math and science

Main article: Alpha (disambiguation)

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 when proving null and alternative hypotheses. In zoology, it is used to name the dominant individual in a wolf or dog pack.

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, a letter based on the lower case of alpha represents the open back unrounded vowel.

History and symbolism

Etymology

Alpha was derived from aleph, which in Phoenician means "ox".

Plutarch

Plutarch, in Moralia, 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, 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

Alpha, both as a symbol and term, is used to refer to or describe a variety of things, including the first or most significant occurrence of something. 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).

Language

The term "alpha" has been used to denote position in social hierarchy, an example being "alpha male".

Computer encodings

• Greek alpha / Coptic alfa

Character	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	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	⍺		⍶		𝚨		𝛂		𝛢		𝛼
Unicode name	APL FUNCTIONAL SYMBOL ALPHA		APL FUNCTIONAL SYMBOL ALPHA UNDERBAR		MATHEMATICAL BOLD CAPITAL ALPHA		MATHEMATICAL BOLD SMALL ALPHA		MATHEMATICAL ITALIC CAPITAL ALPHA		MATHEMATICAL ITALIC SMALL ALPHA
Encodings	decimal	hex	decimal	hex	decimal	hex	decimal	hex	decimal	hex	decimal	hex
Unicode	9082	U+237A	9078	U+2376	120488	U+1D6A8	120514	U+1D6C2	120546	U+1D6E2	120572	U+1D6FC
UTF-8	226 141 186	E2 8D BA	226 141 182	E2 8D B6	240 157 154 168	F0 9D 9A A8	240 157 155 130	F0 9D 9B 82	240 157 155 162	F0 9D 9B A2	240 157 155 188	F0 9D 9B BC
UTF-16	9082	237A	9078	2376	55349 57000	D835 DEA8	55349 57026	D835 DEC2	55349 57058	D835 DEE2	55349 57084	D835 DEFC
Numeric character reference	⍺	⍺	⍶	⍶	𝚨	𝚨	𝛂	𝛂	𝛢	𝛢	𝛼	𝛼

Character	𝜜		𝜶		𝝖		𝝰		𝞐		𝞪
Unicode name	MATHEMATICAL BOLD ITALIC CAPITAL ALPHA		MATHEMATICAL BOLD ITALIC SMALL ALPHA		MATHEMATICAL SANS-SERIF BOLD CAPITAL ALPHA		MATHEMATICAL SANS-SERIF BOLD SMALL ALPHA		MATHEMATICAL SANS-SERIF BOLD ITALIC CAPITAL ALPHA		MATHEMATICAL SANS-SERIF BOLD ITALIC SMALL ALPHA
Encodings	decimal	hex	decimal	hex	decimal	hex	decimal	hex	decimal	hex	decimal	hex
Unicode	120604	U+1D71C	120630	U+1D736	120662	U+1D756	120688	U+1D770	120720	U+1D790	120746	U+1D7AA
UTF-8	240 157 156 156	F0 9D 9C 9C	240 157 156 182	F0 9D 9C B6	240 157 157 150	F0 9D 9D 96	240 157 157 176	F0 9D 9D B0	240 157 158 144	F0 9D 9E 90	240 157 158 170	F0 9D 9E AA
UTF-16	55349 57116	D835 DF1C	55349 57142	D835 DF36	55349 57174	D835 DF56	55349 57200	D835 DF70	55349 57232	D835 DF90	55349 57258	D835 DFAA
Numeric character reference	𝜜	𝜜	𝜶	𝜶	𝝖	𝝖	𝝰	𝝰	𝞐	𝞐	𝞪	𝞪