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Lambda

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Lambda (/ˈlæmdə/ ;[1] uppercase Λ, lowercase λ; Greek: λάμ(β)δα, lám(b)da) is the eleventh letter of the Greek alphabet, representing the voiced alveolar lateral approximant IPA: [l]. In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoenician Lamed. Lambda gave rise to the Latin L and the Cyrillic El (Л). The ancient grammarians and dramatists give evidence to the pronunciation as [laːbdaː] (λάβδα) in Classical Greek times.[2] In Modern Greek, the name of the letter, Λάμδα, is pronounced [ˈlam.ða].

In early Greek alphabets, the shape and orientation of lambda varied.[3] Most variants consisted of two straight strokes, one longer than the other, connected at their ends. The angle might be in the upper-left, lower-left ("Western" alphabets) or top ("Eastern" alphabets). Other variants had a vertical line with a horizontal or sloped stroke running to the right. With the general adoption of the Ionic alphabet, Greek settled on an angle at the top; the Romans put the angle at the lower-left.

The HTML 4 character entity references for the Greek capital and small letter lambda are Λ and λ respectively.[4] The Unicode code points for lambda are U+039B and U+03BB.

The Greek alphabet on a black figure vessel, with a Phoenician-lamed-shaped lambda. The gamma has the shape of modern lambda.

Symbol

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Upper-case letter Λ

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Examples of the symbolic use of uppercase lambda include:

Lower-case letter λ

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Lower-case lambda

Examples of the symbolic use of lowercase lambda include:

Litra symbol

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The Roman libra and Byzantine lítra (λίτρα), which served as both the pound mass unit and liter volume unit, were abbreviated in Greek using lambda with modified forms of the iota subscript ⟨λͅ⟩. These are variously encoded in Unicode. The Ancient Greek Numbers Unicode block includes 10183 GREEK LITRA SIGN (𐆃) as well as 𐅢, which is described as 10162 GREEK ACROPHONIC HERMIONIAN TEN[16] but was much more common as a form of the litra sign. A variant of the sign can be formed from 0338 COMBINING LONG SOLIDUS OVERLAY and either 039B GREEK CAPITAL LETTER LAMDA (Λ̸) or 03BB GREEK SMALL LETTER LAMDA (λ̸).[17]

Unicode

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Unicode uses the (Modern Greek-based) spelling "lamda" in character names, instead of "lambda", due to "the pre-existing names in ISO 8859-7, as well as preferences expressed by the Greek National Body".[18] Latin versions of lambda were added to Unicode in 2024 for the Salishan and Wakashan languages in Canada.[19]

  • U+039B Λ GREEK CAPITAL LETTER LAMDA (Λ)
  • U+03BB λ GREEK SMALL LETTER LAMDA (λ)
  • U+1D27 GREEK LETTER SMALL CAPITAL LAMDA
  • U+2C96 COPTIC CAPITAL LETTER LAULA
  • U+2C97 COPTIC SMALL LETTER LAULA
  • U+A7DA LATIN CAPITAL LETTER LAMBDA
  • U+A7DB LATIN SMALL LETTER LAMBDA
  • U+1038D 𐎍 UGARITIC LETTER LAMDA

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:

  • U+1D6B2 𝚲 MATHEMATICAL BOLD CAPITAL LAMDA
  • U+1D6CC 𝛌 MATHEMATICAL BOLD SMALL LAMDA
  • U+1D6EC 𝛬 MATHEMATICAL ITALIC CAPITAL LAMDA
  • U+1D706 𝜆 MATHEMATICAL ITALIC SMALL LAMDA
  • U+1D726 𝜦 MATHEMATICAL BOLD ITALIC CAPITAL LAMDA
  • U+1D740 𝝀 MATHEMATICAL BOLD ITALIC SMALL LAMDA
  • U+1D760 𝝠 MATHEMATICAL SANS-SERIF BOLD CAPITAL LAMDA
  • U+1D77A 𝝺 MATHEMATICAL SANS-SERIF BOLD SMALL LAMDA
  • U+1D79A 𝞚 MATHEMATICAL SANS-SERIF BOLD ITALIC CAPITAL LAMDA
  • U+1D7B4 𝞴 MATHEMATICAL SANS-SERIF BOLD ITALIC SMALL LAMDA

See also

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References

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  1. ^ "lambda". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ Herbert Weir Smyth. A Greek Grammar for Colleges. I.1.c
  3. ^ "Epigraphic Sources for Early Greek Writing". Poinikastas.CSAD.ox.ac.uk. Retrieved 2011-10-03.
  4. ^ "HTML 4.01 Specification. 24. Character entity references in HTML 4". World Wide Web Consortium.
  5. ^ Philodemus (2003). On Poems. Oxford University Press. p. 212. ISBN 9780199262854.
  6. ^ Nelkon, Michael (1977). Fundamentals of Physics. St. Albans, Hertfordshire: Hart-Davis Educational. p. 329.
  7. ^ "Encyclopedia Astronautica: Lambda". Astronautix.com. Archived from the original on 2012-10-22. Retrieved 2012-12-18.
  8. ^ Wankat Separation Process Engineering 2nd ed, Prentice Hall
  9. ^ "Half-Life on Steam". store.steampowered.com. Valve. Retrieved 2017-01-02.
  10. ^ "Half-Life 2 on Steam". store.steampowered.com. Valve. Retrieved 2017-01-02.
  11. ^ Rapp, Linda (2004). "Gay Activists Alliance" (PDF). glbtq.com.
  12. ^ "1969, The Year of Gay Liberation". The New York Public Library. June 2009. Retrieved 17 November 2018.
  13. ^ Goodwin, Joseph P. (1989). "It Takes One to Know One". More Man Than You'll Ever Be: Gay Folklore and Acculturation in Middle America. Indiana University Press. p. 26. ISBN 978-0253338938.
  14. ^ Rapp, Linda (2003). "Symbols" (PDF). glbtq.com.
  15. ^ Haggerty, George E., ed. (2000). Gay Histories and Cultures: An Encyclopedia (Encyclopedia of Gay Histories and Cultures, Volume II) (1 ed.). London: Garland Publishing. p. 529. ISBN 0-8153-1880-4. OCLC 750790369.
  16. ^ Unicode Ancient Greek Numbers block.
  17. ^ "Thesaurus Linguae Graecae" (PDF). Stephanus.TLG.UCI.edu. Archived from the original (PDF) on 2011-07-16.
  18. ^ "Unicode Mail List Archive: RE: Greek letter "LAMDA"?".
  19. ^ Humchitt, Robyn; Jacquerye, Denis; King, Kevin (2023-07-17). "L2/23-191: Proposal to Encode 3 Additional Latin Characters for Wakashan and Salishan Languages to the Unicode Standard" (PDF).