| 释义 |
omega|ˈəʊmɪgə, əʊˈmɛgə|
[Gr. ὦ µέγα i.e. ‘great O’, in contradistinction to ὂ µικρόν ‘little O’.]
1. The last letter (Ω, ω) of the Greek alphabet, having originally the value of long open ō.
c1400Mandeville Trav. (1725) iii. 25 What Lettres thei ben..with the Names..α Alpha, β Betha..ω Omega. [1573–80Baret Alv. O, The Greekes therefore haue ωµικρον standing for a short o: and ωµεγα for this double or long o, oo.] 1640S. Daines Orthoepia Anglicana (1908) 11 Oa, sounds generally after the Greeke Omega. Ibid. 12 Oo in Poore imitates in sound the Greek Omega. 1656in Blount Glossogr., Omega. 1727–41Chambers Cycl. s.v. O, The Greeks had two O's, viz. omicron, ο, and omega ω. 1897Allbutt's Syst. Med. III. 815 The outline of such a loop is that of a capital omega.
2. transf.
a. The last of a series; the last word; the end or final development. alpha and omega: see alpha 2. Also from alpha to omega: from beginning to end; from top to toe.
1526Tindale Rev. i. 8, I am Alpha and Omega the fyrst and the laste. 1651N. Bacon Disc. Govt. Eng. ii. xxviii. (1739) 132 Formerly the Pope usurped the power to be the Omega to the resolves of all Councils. 1746Wesley Hymn, ‘Love Divine’ ii, Alpha and Omega be. 1800Asiat. Ann. Reg., Proc. E. Ind. Ho. 85/1 A letter..contained the alpha and the omega of the business. 1832Tennyson Two Voices 278 ‘Omega! thou art Lord’, they said, ‘We find no motion in the dead’. 1851Neale Hymn, ‘Draw nigh, and take’, Alpha and Omega, to whom shall bow All nations at the Doom, is with us now. 1886Athenæum 25 Dec. 863/3 These two volumes may be considered as the omega of Hebrew bibliography. 1929D. G. Mackail How Amusing! 307, I was a gentleman..from alpha to omega. 1978D. Quinn Fear of God ii. 161 Vast explosions of silence..marching..from Alpha to Omega and..beyond the infinite.
b. Omega point, in the work of P. Teilhard de Chardin (1881–1955) a hypothesized point of convergence, absorption, or transformation which is the divine end, or God, towards which the forces of evolution are moving (see quot. 1964).
1959B. Wall tr. Teilhard de Chardin's Phenomenon of Man ii. 57 He goes on to add these words which my readers would do well to recall when I come to unveil (with all due reservations and corrections) the perspective of the ‘Omega point’. Ibid. iv. ii. 259 Accordingly its enormous layers, followed in the right direction, must somewhere ahead become involuted to a point which we might call Omega, which fuses and consumes them integrally in itself. 1964N. Denny tr. Teilhard de Chardin's Future of Man vi. 122 Ahead of, or rather in the heart of, a universe prolonged along its axis of complexity, there exists a divine centre of convergence... In order to stress its synthesising and personalising function, let us call it the point Omega. 1965Listener 3 June 817/2 The idea has something in common with Teilhard de Chardin's concept of the ‘Omega Point’. 1977Time 28 Feb. 45/1 Teilhard believed man would eventually transcend his individualism and converge at the ‘Omega Point’ with the Omega—God.
3. Nuclear Physics.
†a. (Written Ω.) A former designation of certain hyperons. Obs.
The decay schemes in quot. 1953 are those of the sigma (σ) particles, whilst the mass specified in quot. 19542 (and elsewhere) is that of the xi minus. In quot. 19541 a lambda particle is referred to.
1953Nuovo Cimento X. 1741 Two decay schemes have been proposed by analogy with the decay of V10-particles. Adopting the nomenclature proposed at the Bagnères Conference these are: (a) Ωπ{pm} → n + π{pm} + Q, (b) Ωp+ → p + π0 + Q. 1954Sci. News XXXI. 62 Ω0-particle. Mass, 2,184 {pm} 7 [≡ 1116 MeV]. Lifetime, (3·3 {pm} 1) × 10-10 seconds... Decay scheme: Ω0 → p+ + π-. 1954Physical Rev. XCVI. 543/1 The known hyperons, λ-, Ω-, have masses equivalent to 1200 and 1320 Mev, respectively.
b. In full omega meson. A neutral meson with zero hypercharge, zero isospin, unit spin, and negative parity that is observed as a resonance (as when protons and antiprotons of sufficient energy collide), has a mass of 784 MeV (1534 times that of the electron), and on decaying usu. produces a positive, a negative, and a neutral pion. Freq. written as ω.
1961B. C. Maglić et al. in Physical Rev. Lett. VII. 178/1 The existence of a heavy neutral meson with T = 0 and J = 1- was predicted by Nambu... Such a particle is also expected in the vector meson theory of Sakurai and.. according to the unitary symmetry theory; and for other reasons. We will refer to it as ω. Ibid. 181/1 We conclude that the data fit the qualitative criteria for an axial vector matrix element (ω meson). 1961New Scientist 5 Oct. 48/1 Four physicists at the Lawrence Radiation Laboratory, Berkeley, have made observations..that appear to indicate unequivocally the presence, in a proton-antiproton reaction, of the omega-meson. 1971Sci. News 10 Apr. 250 It appears that electromagnetic forces are mediated to leptons directly by photons and to hadrons by phi, rho or omega. 1971Sci. Amer. July 100/2 Three vector mesons with zero strangeness are currently known: the rho, the omega and the phi. 1974Nature 6 Dec. 438/2 The omega meson, which has all the same normal quantum numbers as the phi,..decays very rapidly to three pions.
c. omega minus (or omega particle): a negatively charged hyperon having hypercharge of -2, zero isospin, a spin of 3/2, positive parity, and a mass of 1672 MeV (3272 times that of the electron), and decaying via the weak interaction into either a xi particle and a pion or a lambda particle and a kaon. Freq. written as Ω-.
1962M. Gell-Mann in Proc. Internat. Conf. High-Energy Physics 805/2 Starting with the resonance at 1238 MeV, we may conjecture that the Y1*, at 1385 MeV and the ξ* at 1535 MeV might belong to this supermultiplet... If J = 3/2+ is really right for these two cases, then our speculation might have some value and we should look for the last particle, called, say, Ω- with S = -3, I = 0. At 1685 MeV, it would be metastable and should decay by the weak interactions into K- + λ, π- + ξ0, or π0 + ξ-. 1964Physical Rev. Lett. XII. 204/1 The multitude of resonances which have been discovered recently..can be arranged as a decuplet with one member still missing... This particle (which we shall call Ω-, following Gell-Mann) is predicted to be a negatively charged isotopic singlet with strangeness minus three. Ibid. 206/1 In view of the properties..established for particle 3, we feel justified in identifying it with the sought-for Ω-. 1964Daily Tel. 21 Feb. 25/2 Dr. Maurice Goldhaber, director of Brookhaven, said yesterday: ‘The discovery of Omega Minus forms the capstone in a building which was so far held together only by the bold imagination of Dr. Gell-Mann and Dr. Ne'eman.’ 1964Listener 30 Apr. 711/1 The new theory [sc. that of unitary symmetry] has made one striking prediction which was subsequently found to be correct: the observation of the negatively charged Omega particle. 1972Daily Colonist (Victoria, B.C.) 24 Feb. 5/2 The physicists hope to make the first observation of ‘quarks’..by studying the activity of a rare and elusive sub-atomic particle called the omega-minus. 1974Frauenfelder & Henley Subatomic Physics i. 6 The negative kaon..collides with a proton and produces a positive kaon, a neutral kaon, and an omega minus. The Ω- decays into a ξ0 and a π-.
4. a. attrib. and Comb., as omega-shaped adj.
1880Mrs. Gray 14 Months in Canton xxviii. 301 They are always in the Omega or horse-shoe form. 1885Where Chineses Drive 19 The omega-shaped tombs so common in the south [of China].
b. Used attrib. (with capital initial) to designate a style of interior decoration and design associated with the Omega Workshops, a short-lived undertaking begun in London by the art critic Roger Fry in 1913 and influenced by the work of William Morris.
1922D. H. Lawrence Aaron's Rod iii. 30 Into this reticence pieces of futurism, Omega cushions and Van-Gogh-like pictures exploded their colours. 1970Oxf. Compan. Art 790/2 The Omega artists believed that the creative joy of the artist and craftsman should go into the making of articles for everyday use. 1973Guardian 22 Jan. 8/1 Drawings and paintings of the Bloomsbury artists still crowd the walls... The dining-room's Omega chairs attend its round painted table. |