twistorn.
/ˈtwɪstə/ 1. Computing. Also -er. A non-volatile memory element consisting of an insulated copper wire wound helically round with a wire of readily magnetized material. Frequently attributive.
ΘΚΠ
society > computing and information technology > hardware > [noun] > primary storage or main memory > core memory
core1950
twistor1957
1957 A. H. Bobeck in Bell Syst. Techn. Jrnl. 36 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’.
1962 Flight Internat. 82 170/1 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.
1975 D. 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, 19731).
ΘΚΠ
the world > matter > physics > relativity > space-time > [noun] > spinor used in descriptions
twistor1967
the world > matter > physics > quantum theory > quantum mechanics > quantum field theory > [noun] > quantity existing in a space > type of
twistor1967
1967 R. 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 R. Penrose & 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.
1973 R. Penrose & MacCallum in Physics Rep. VI. 244 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.
1979 New 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.
This entry has not yet been fully updated (first published 1986; most recently modified version published online September 2018).
<
n.1957