| 释义 |
▪ I. tau|tɔː, taʊ|
Also 4, 6 taue, 4 tav, 4–8 taw, 5 tayu, tayewe.
[a. Gr. ταῦ, name of the letter T in the Greek alphabet, as in the Semitic whence the Greek was derived: see T, the letter.]
1. The name of the letter T in the Greek, Hebrew, and ancient Semitic alphabets. Often in the sense ‘last letter’, as tau was orig. in Greek, and continued to be in Hebrew, etc.
a1300Cursor M. 12199–12204 Þe letters fra alpha to taw [Gött. tau, F. taw, Tr. tayu], Wit sundri sight man mai þam knau [Tr. sew]. Quat es taw, sai first to me, And i sal vndo alpha to þe; For he þat alpha can noght se, Hu sal he wijt quat tav mai be? 1838Jackson tr. Krummacher's Elisha ix. 199 Set a mark upon them..a Tau, the last letter of the Hebrew alphabet, upon their foreheads. 1883I. Taylor Alphabet I. 239 The letters he, lamed, and tau are almost the same in the Siloam inscription as on the Moabite stone, which is older by a century and a half. Ibid. II. 106 The persistency in the shape of tau, which varies less than any other letter, our modern capital T hardly differing from the [Phœnician] Baal Lebanon form.
2. a. A mark of the shape of the letter T, a St. Anthony's cross; a figure of this as a sacred symbol (also in Heraldry). Also formerly applied to the sign of the cross as made with the hand.
a1300Cursor M. 6078 (Cott.) On aiþer post þer hus to smer, A takin o tav on þair derner [Gott. On ilk derner, A sine of tau T [Trin. thayu] make ȝe þer]. Ibid. 21711–6 Þe signe o tav in ald laies Bitakens cros nu in vr daies... Tau and cros bath er als an, Bot tav has yerd a-bouen nan. c1446Lydg. Nightingale Poems ii. 318 This banner is most myghti of vertu,..Most noble signe and token of Tau. 1700J. A. Astry tr. Saavedra-Faxardo II. 316 It is by the Tau they are stampt with, that they are assured of their real Value. 1704J. Harris Lex. Techn. I, Taw, the Heralds have an Ordinary which they reckon among the Crosses, called by this Name, and of this Figure. 1895Q. Rev. July 213 Tradition may conceive that the Tau was the mark of Cain. 1908Ibid. July 142 Little images of bad silver, with the Saint's bell, his ‘Tau’ and the notorious pig.
b. Applied to the crux ansata of ancient Egyptian symbolism, the ankh ☥.
1785[see ansated ppl. a.]. 1841J. G. Wilkinson Manners & Customs Ancient Egyptians 2nd Ser. II. xv. 283 The sacred tau, or sign of Life, was presented to him. 1857Wilkinson Egypt. Time Pharaohs 133 The gods hold in one hand the sacred Tau, or sign of life. 1877A. B. Edwards Up Nile ix. 238. 1886 C. R. Conder Syrian Stone Lore 253 note, The emblems of the..phœnix, the tau, the labarum, and the fylfot occur, but not the cross.
3. A T-shaped pastoral staff.
1855tr. Labarte's Arts Mid. Ages xiii. 381 Pastoral staff called..a Tau. 1875W. Maskell Ivories 84 The Tau..is but a form of the pastoral staff, adopted in more than one country of Western Europe early in the middle ages.
4. A name, or part of the name, of various animals having markings resembling the letter T.
a. The toad-fish (Batrachus tau) of the Atlantic coast of N. America.
b. A kind of moth: see quot. 1832; also, a kind of beetle, and of fly.
1832J. Rennie Conspect. Butterfl. & Moths 36 Bombycidæ (Stephens)... The Tau Emperor [Moth] (Aglaia Tau, Ochsenheimer). Said to be British on doubtful authority.
5. Particle Physics. Freq. written τ.
a. A meson that decays into three pions, now identified with the kaon. Also tau meson.
1949Nature 15 Jan. 86/2 We have considered the possible relations of the present results to the particles..referred to as τ-mesons, evidence for which has been recently reported by Bradt and Peters. 1955Proc. Glasgow Conf. Nucl. & Meson Physics 1954 347 The striking similarity of the masses of the θ0 and τ{pm} mesons. 1968M. S. Livingston Particle Physics vii. 138 The θ decayed into two pions while the τ decayed into three pions. 1973L. J. Tassie Physics Elem. Particles vii. 61 The solution to the θ–τ puzzle was that the θ and τ particles were the same, now called the K-meson, and the parity was not conserved in the decay of K-mesons. 1974Frauenfelder & Henley Subatomic Physics ix. 205 The decays of the tau and the theta were so slow that they were known to be weak.
b. An unstable heavy charged lepton which has a spin of ½ and a mass of approximately 1780 MeV (3490 times that of the electron) and which decays into an electron or muon or into hadrons, in every case with one or more neutrinos. Also tau lepton, tau particle.
1977M. L. Perl in Proc. Internat. Symposium Lepton & Photon Interactions at High Energies 146 All..data..agree on the following points... c. The behavior of these [leptonic] events is consistent with the hypothesis that a new charged lepton, τ, exists with a mass of 1.9 {pm} 0.1 GeV/c2. 1978Perl & Kirk in Sci. Amer. Mar. 50/3 We shall relate here the story of the discovery of the new heavy lepton and its antiparticle, which we have named the tau and the antitau. 1979McGraw-Hill Yearbk. Sci. & Technol. 240/1 It was first discovered through reaction (1), in which a positron (e+) and electron (e-) annihilate and produce a pair of τ-leptons of opposite electrical charge. 1980Sci. Amer. July 60/1 More recently a third neutrino flavor has been added to accompany the newly discovered tau particle, which is a massive sibling of the electron and the muon. 1981D. H. Perkins in J. H. Mulvey Nature of Matter iv. 79 The neutrino is a muon-type neutrino and in subsequent interactions will always produce a charged µ, not an e or τ.
6. attrib. and Comb., as tau-shaped adj. (= T-shaped); tau-bone, a T-shaped bone, as the interclavicle; tau-cross, a T-shaped cross (= sense 2); so tau-crucifix; tau-ring, ? a ring inscribed with the letter T; tau-staff, a T-shaped staff (= sense 3).
1474Will Ld. Mountioye (Somerset Ho.), A *Tayewe crosse. 1562Leigh Armorie 60 b, Ouer all a crosse Taue. 1885Blackw. Mag. July 129/2 The tau cross, crux ansata, St. Anthony's cross,..is the commonest of all primitive symbols. 1888F. G. Lee in Archæologia LI. 356 There are..no less than five heads of tau-crosses preserved in the South Kensington Museum.
1877W. Jones Finger-ring 155 A very interesting collection of so-called *Tau (T) rings were exhibited.
1888F. G. Lee in Archæologia LI. 356 A figure of a bishop or abbot..bearing a *tau-shaped staff. 1905Athenæum 10 June 727/2 A tau-shaped central chamber.
1885M'Crie Sk. & Stud. 37 The other carries a cross-headed or *tau-staff. 1888F. G. Lee in Archæologia LI. 356 Head of a tau-staff of the eleventh century.
▪ II. tau, taubator
obs. ff. taw n.2, taberdar.
▪ III. tau
obs. var. tao. |