#Telectron sun alarm clock portable#

The main variety of atomic clock uses caesium atoms cooled to temperatures that approach absolute zero. The timekeeping accuracy of the involved atomic clocks is important because the smaller the error in time measurement, the smaller the error in distance obtained by multiplying the time by the speed of light is (a timing error of a nanosecond or 1 billionth of a second (10 −9 or 1⁄ 1,000,000,000 second) translates into an almost 30-centimetre (11.8 in) distance and hence positional error).

The accurate timekeeping capabilities of atomic clocks are also used for navigation by satellite networks such as the European Union's Galileo Programme and the United States' GPS. The system of Coordinated Universal Time (UTC) that is the basis of civil time implements leap seconds to allow clock time to track changes in Earth's rotation to within one second while being based on clocks that are based on the definition of the second. This definition is the basis for the system of International Atomic Time (TAI), which is maintained by an ensemble of atomic clocks around the world. It is defined by taking the fixed numerical value of the caesium frequency, Δ ν C s, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s −1. The second, symbol s, is the SI unit of time. This phenomenon serves as the basis for the International System of Units' (SI) definition of a second: Electron states in an atom are associated with different energy levels, and in transitions between such states they interact with a very specific frequency of electromagnetic radiation. It is based on atoms having different energy levels. The black units in the foreground are Microsemi (formerly Sigma-Tau) MHM-2010 hydrogen maser standards.Īn atomic clock is a clock that measures time by monitoring the resonant frequency of atoms. The rack mounted units in the background are Microsemi (formerly HP) 5071A caesium beam clocks. Naval Observatory in Washington, D.C., which provides the time standard for the U.S. The master atomic clock ensemble at the U.S. 2020-001.NIST physicists Steve Jefferts (foreground) and Tom Heavner with the NIST-F2 caesium fountain atomic clock, a civilian time standard for the United States Wristwatch with “Nintendo Tetris“ computer game, EM Entertainment, Munich, around 1991, Inv. His passion for the game is still visible today: The tooth marks on the wristband show how fiercely he used to play it back then. The owner of this watch was only six years old, too, when he got it as a gift in 1991.

After all, the addiction factor of one single game could not be that high… Among these children, Tetris watches became cult objects – and they were permitted in most cases.

This is why many younger students did not have their parents’ permission to get their own “Game Boys“.

Many parents feared that their children might become addicted to computer games. It was Nintendo’s “Game Boy“ that triggered the breakthrough of this “killer application“ in 1989.

#Telectron sun alarm clock portable#

Is there anyone who doesn’t know that classic among the video games for portable consoles - Tetris? In this game, individual pieces must be arranged in such a way that they form a continuous area without empty spaces.