time-likeadj.
/ˈtʌɪmˌlʌɪk/, U.S. /ˈtaɪmˈlaɪk/ Physics.
Designating an interval (interval n. 2c) between two points in space-time that can in principle be observed to be separated only by time (that is, to occupy the same point in space as seen by a moving observer); relating to such an interval. Cf. space-like adj.Events separated by time-like intervals are causally connected: there is enough time between them for light to pass from one to the other (they lie within each other's light-cones).
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the world > matter > physics > relativity > space-time > [adjective] > designating points in space-time
space-like1914
time-like1914
1914 L. Silberstein Theory of Relativity v. 134 A vector..in the plane x, ct, drawn from O to any point of the region limited by LON, or L1ON1, satisfying the condition (23a), may be called a time-like vector.
1920 A. S. Eddington Space, Time & Gravitation iii. 60 Even if the discovery of a new ray led us to modify the reckoning of time and space, it would still be necessary in the study of material systems to preserve the present absolute distinction of time-like and space-like intervals.
1955 O. Klein in W. Pauli Niels Bohr & Devel. Physics 112 We divide the k-states into those belonging to time-like k-vectors..and those belonging to space-like k-vectors.., a division which is relativistically invariant.
1978 J. M. Pasachoff & M. L. Kutner University Astron. xxvii. 694 The world lines of light divide spacetime into spacelike and timelike regions.
2005 M. Lockwood Labyrinth of Time (2007) xv. 324 In adulthood, however, he finds a suitable closed timelike curve, and a vehicle that enables him to follow it back to the vicinity of grandfather's bachelor flat in 1920.
This entry has been updated (OED Third Edition, March 2012; most recently modified version published online March 2022).
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adj.1914