| 释义 |
twistor|ˈtwɪstə(r)|
[f. twist v. + -or.]
1. Computers. Also -er. A non-volatile memory element consisting of an insulated copper wire wound helically round with a wire of readily magnetized material. Freq. attrib.
1957A. H. Bobeck in Bell Syst. Technical Jrnl. XXXVI. 1319 Three methods have been developed for storing information in a coincident-current manner on magnetic wire. The resulting memory cells have been collectively named the ‘twistor’. 1962Flight Internat. LXXXII. 170/1 A permanent twistor memory and a ferrite-core scratch-pad memory are vital to reliability, assuring continuous operation until an attacking missile is intercepted and destroyed. 1975D. G. Fink Electronics Engineers' Handbk. xxii. 19 A twister memory is used as the semipermanent memory constituting a major portion of the program store in central control.
2. Physics. A type of spinor used in some descriptions of space-time (see quots. 1967, 1973).
1967R. Penrose in Jrnl. Math. Physics VIII. 346 Twistors are..the ‘spinors’ which are relevant to the six-dimensional space whose (pseudo-) rotation group is isomorphic with the conformal group of ordinary Minkowski space-time. The simplest (non-scalar) twistors constitute a four-dimensional, four-valued representation of the restricted conformal group... The general twistor is then a many-index quantity constructible from the above basic twistors by means of the usual ‘tensor type’ rules. 1973― & MacCallum in Physics Rep. VI. 244 Twistors (that is to say, the original flat-space twistors about which these notes are mainly concerned) are actually the reduced spinors for the proper pseudo-orthogonal group SO(2,4) which is locally isomorphic with, and 2-1 homomorphic with, the restricted conformal group of flat space-time. Ibid., A twistor (of the simplest type) can be pictured ‘classically’ as effectively a zero rest-mass particle in free motion, where the particle may possess an intrinsic spin. 1979New Scientist 31 May 737 Twistor theory is incomplete, but it offers considerable hope for a quite new approach to the basic problems of theoretical physics. |