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space-time
(Encyclopedia)space-time, central concept in the theory of relativity that replaces the earlier concepts of space and time as separate absolute entities. In relativity one cannot uniquely distinguish space and time...sidereal time
(Encyclopedia)sidereal time (ST), time measured relative to the fixed stars; thus, the sidereal day is the period during which the earth completes one rotation on its axis so that some chosen star appears twice on ...time zone
(Encyclopedia)time zone: see standard time.time-division
(Encyclopedia)time-division: see multiplexing. ...daylight saving time
(Encyclopedia)daylight saving time (DST), time observed when clocks and other timepieces are set ahead so that the sun will rise and set later in the day as measured by civil time. The amount of daylight on a given...local solar time
(Encyclopedia)local solar time: see solar time. ...mean solar time
(Encyclopedia)mean solar time: see solar time. ...equation of time
(Encyclopedia)equation of time: see solar time. ...apparent solar time
(Encyclopedia)apparent solar time: see solar time. ...equal-time rule
(Encyclopedia)equal-time rule, a Federal Communications Commission rule that requires equal air time for all major candidates competing for political office. It was preceded by the fairness doctrine, abolished in 1...Browse by Subject
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