The Collaborative International Dictionary
Clock \Clock\ (kl[o^]k), n. [AS. clucge bell; akin to D. klok clock, bell, G. glocke, Dan. klokke, Sw. klocka, Icel. klukka bell, LL. clocca, cloca (whence F. cloche); al perh. of Celtic origin; cf. Ir. & Gael. clog bell, clock, W. cloch bell. Cf. Cloak.]
A machine for measuring time, indicating the hour and other divisions; in ordinary mechanical clocks for domestic or office use the time is indicated on a typically circular face or dial plate containing two hands, pointing to numbers engraved on the periphery of the face, thus showing the hours and minutes. The works of a mechanical clock are moved by a weight or a spring, and it is often so constructed as to tell the hour by the stroke of a hammer on a bell. In electrical or electronic clocks, the time may be indicated, as on a mechanical clock, by hands, but may also be indicated by direct digital readout, with the hours and minutes in normal Arabic numerals. The readout using hands is often called analog to distinguish it from the digital readout. Some clocks also indicate the seconds. Clocks are not adapted, like the watch, to be carried on the person. Specialized clocks, such as atomic clocks, may be constructed on different principles, and may have a very high precision for use in scientific observations.
A watch, esp. one that strikes. [Obs.]
--Walton.The striking of a clock. [Obs.]
--Dryden.-
A figure or figured work on the ankle or side of a stocking. --Swift. Note: The phrases what o'clock? it is nine o'clock, etc., are contracted from what of the clock? it is nine of the clock, etc. Alarm clock. See under Alarm. Astronomical clock.
A clock of superior construction, with a compensating pendulum, etc., to measure time with great accuracy, for use in astronomical observatories; -- called a regulator when used by watchmakers as a standard for regulating timepieces.
-
A clock with mechanism for indicating certain astronomical phenomena, as the phases of the moon, position of the sun in the ecliptic, equation of time, etc. Electric clock.
A clock moved or regulated by electricity or electro-magnetism.
-
A clock connected with an electro-magnetic recording apparatus.
Ship's clock (Naut.), a clock arranged to strike from one to eight strokes, at half hourly intervals, marking the divisions of the ship's watches.
Sidereal clock, an astronomical clock regulated to keep sidereal time.
Wiktionary
n. (atomic clock English)
Usage examples of "atomic clocks".
On the contrary, there is an extremely wide range of experience - with nuclear accelerators and atomic clocks, for example - in precise quantitative agreement with special relativity.
Specialized atomic clocks can verify this prediction to better than one part in 1,000.
They hoped to show that as the rocket gained altitude (thereby decreasing the effect of the earth's gravitational pull), an identical earthbound atomic clock (still subject to the full force of the earth's gravity) would tick more slowly Through a two-way stream of microwave signals, the researchers were able to compare the rate of ticking of the two atomic clocks and, indeed, at the rocket's maximum altitude of 6,000 miles, its atomic clock ran fast by about 4 parts per billion relative to its counterpart on earth, agreeing with theoretical predictions to better than a hundredth of a percent.
Experiments carrying atomic clocks around the Earth on jumbo jets have verified this scenario, but aircraft are so slow compared to light that the time difference observed (and predicted) is only the tiniest fraction of a second.
Experiments carrying atomic clocks around the Earth on jumbo jets have verified this scenario, but aircraft are so slow compared to light that the time difference observed (and pre.
I watched ver tinkering with the software, waiting for some conjunction of satellites and atomic clocks, and wondered: Would I have been happier, if I'd made the same decisions?
Set to the Naval Observatory Master clock, which was based on fifty-eight atomic clocks, it was phenomenally accurateto within ten nanoseconds.
We did have the advantage of accurate atomic clocks, or so we thought.
The NAVSTAR satellites use atomic clocks to measure time with great precision, and the really sexy part of the system is also encrypted.