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:
“We early arrive at the great discovery that there is one mind common to all individual men: that what is individual is less than what is universal ... that error, vice and disease have their seat in the superficial or individual nature.”
—Ralph Waldo Emerson (1803–1882)
“The time of universal peace is near.
Prove this a prosp’rous day, the three-nooked world
Shall bear the olive freely.”
—William Shakespeare (1564–1616)