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:
“Necessity does everything well. In our condition of universal dependence, it seems heroic to let the petitioner be the judge of his necessity, and to give all that is asked, though at great inconvenience.”
—Ralph Waldo Emerson (1803–1882)
“There are some who become spies for money, or out of vanity and megalomania, or out of ambition, or out of a desire for thrills. But the malady of our time is of those who become spies out of idealism.”
—Max Lerner (b. 1902)