Universal Time (UT) is a time standard based on the rotation of the Earth. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the Prime Meridian at Greenwich, and GMT is sometimes used loosely as a synonym for UTC. In fact, the expression "Universal Time" is ambiguous, as there are several versions of it, the most commonly used being UTC and UT1 (see below). All of these versions of UT are based on the rotation of the Earth in relation to distant celestial objects (stars and quasars), but with a scaling factor and other adjustments to make them closer to solar time.
Read more about Universal Time: Universal Time and Standard Time, Measurement, Versions
Famous quotes containing the words universal and/or time:
“Hail, Source of Being! Universal Soul
Of heaven and earth! Essential Presence, hail!
To thee I bend the knee; to thee my thoughts
Continual climb, who with a master-hand
Hast the great whole into perfection
touched.”
—James Thomson (1700–1748)
“I never knew anyone yet who got up at six who did anything more useful between that time and breakfast than banging a tennis ball up against the side of the house, waiting for the more civilized members of the party to get up.”
—Robert Benchley (1889–1945)