Atomic Time

Some articles on time, atomic time, atomic:

Tropical Year - Time Scales
... As mentioned in History, advances in time-keeping have resulted in various time scales ... One useful time scale is Universal Time (especially the UT1 variant), which is the mean solar time at 0 degrees longitude (the Greenwich meridian) ... This time scale is known to be somewhat variable ...
Time Zone - Definition
... Before 1972, all time zones were specified as an offset from Greenwich Mean Time (GMT), which was the mean solar time at the meridian passing ... Since 1972 all official time services have broadcast radio time signals synchronized to UTC, a form of atomic time that includes leap seconds to keep it within 0.9 seconds of this former GMT, now called ... Many countries now legally define their standard time relative to UTC, although some still legally refer to GMT, including the United Kingdom itself ...
Theoretical Astronomy - Theory of Astronomical Time Keeping - Atomic Time
... a device is required that attempts to produce the SI second (s) such as an atomic clock ... the Atomic Time TAI ... From the General theory of relativity the time measured depends on the altitude on Earth and the spatial velocity of the clock so that TAI refers to a location on sea level that rotates with the Earth ...
Second - History - Modern Measurements
... As a unit of time, the second (meaning the second division by 60 of an hour) entered English in the late 16th century, about a hundred years before it was measured accurately ... In 1832, Gauss proposed using the second as the base unit of time in his millimeter-milligram-second system of units ... are agreed to use the second of mean solar time as the unit of time." BAAS formally proposed the CGS system in 1874, although this system was gradually ...

Famous quotes containing the words time and/or atomic:

    It would be idle to say that we were not, from time to time, aware that a volcano slumbered fitfully beneath us. There were dark sides to the Slavery Question, for master, as for slave.
    Marion Harland (1830–1922)

    The atomic bomb certainly is the most powerful of all weapons, but it is conclusively powerful and effective only in the hands of the nation which controls the sky.
    Lyndon Baines Johnson (1908–1973)