Unnumbered source etymology
Original entry ↗The letter Τ /τ in the Greek alphabet; being the nineteenth letter of the Classical and Modern Greek, and the twenty-first letter of the Old and Ancient Greek alphabets. · Alternative form of taw; the 22nd and last letter of many Semitic alphabets/abjads, including Phoenician, Aramaic, Hebrew, Syriac, and Arabic. · A Τ-shaped object or sign; a Saint Anthony's cross, sometimes regarded as a sacred symbol. · A crosier with a Τ-shaped head.
From Middle English tau, taue, from Latin tau, from Ancient Greek ταῦ (taû) and Hebrew תָּו (tav). Sense 7 was used by Joseph M. Lindenberg in 1991, and popularized by the American educator and entrepreneur Michael Hartl in a 2010 paper which explains that τ resembles π; and that τ is the Greek equivalent of t, the first letter of turn, and 2π corresponds to one turn of a circle with a radius of one unit. Sense 8.1 (“ellipsis of tau lepton or tau particle”) was coined by the American physicist Martin Lewis Perl (1927–2014) after the first letter of Ancient Greek τρίτον (tríton, “third”), since the tau lepton or tauon was the third charged lepton discovered.
Relationships mentioned by the source
These are extracted mentions, not a timeline or a verified sequence of immediate parents.
This page abbreviates 7 auxiliary source items. The etymology narrative is not shortened. Omission counts are available in the audit fields below; consult the original for complete auxiliary material.
Inspect preserved source fields
Raw extraction fields are retained for auditing. Their order does not establish ancestry.
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"The letter Τ /τ in the Greek alphabet; being the nineteenth letter of the Classical and Modern Greek, and the twenty-first letter of the Old and Ancient Greek alphabets.",
"Alternative form of taw; the 22nd and last letter of many Semitic alphabets/abjads, including Phoenician, Aramaic, Hebrew, Syriac, and Arabic.",
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