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How Do Atomic Clocks Work?

If time is crucial to you or your office,where one of the world's few of the world's
consider investing in atomic clocks so thatatomic clocks operates. A low -frequency
everyone knows exactly what time it is andradio signal broadcasts the time from that
everyone has the same time. These are thelocation to all atomic clocks within its
most accurate time keeping pieces you canrange. There are currently approximately 200
get, and more and more businesses are usingatomic  clocks world-wide in sixty countries.
atomic wall clocks to make sure that accurate
time  sheets  and  appointments  are  kept.In the United States, most atomic clocks used
for home and offices are synchronized to the
But what are atomic clocks and why are theyNational Institutes of Standards and
so much more accurate than regular clocks? ATechnology atomic clock in Boulder, Colorado.
standard clock, whether wind-up, electric orThe other official atomic clock is at the
battery operated, counts time by the numberU.S. Naval Observatory in Washington, D.C.
of "ticks" that a resonator makes. Theand is the official time clock of the
resonator is the device that actually keepsDepartment of Defense. Since both of these
track of time. In most clocks the resonatoratomic clocks are within one second of each
is either a swinging pendulum or (in digitalother over a million years of time, it is
clocks) oscillations in the power line (whichunlikely that time displayed on atomic wall
is a bit different in the U.S. and inclocks at the Pentagon will differ from the
Europe).time displayed on an atomic clock in your
home  office!
Atomic clocks also use a resonator, but the
resonator counts based on the resonanceHow Do At-Home Clocks Get the Information
frequency of atoms. Resonance is the emissionfrom  Master  Atomic  Clocks?
or absorption of microwave electromagnetic
radiation by an atom. It is very regular, andGlobal positioning satellites (GPS) in the
no matter which atom of cesium used, theskies above us transmit the signals from the
frequency of resonance is always exactly theofficial atomic clocks to individual
same. This is why atomic clocks are so muchreceivers in atomic wall clocks and desk
more accurate than other clocks - theclocks all over the world. In other
resonators in other clocks can be affected bycountries, the signal would come from
lots of variables like temperature, moisturewhichever clock is the official atomic clock
and atmospheric conditions. None of thesefor that region, just as the one in Boulder,
affect the atoms, so the atomic clocks neverColorado  is  the  one for the United States.
lose  or  gain  time.
These amazingly accurate atomic clocks are
Synchronization  of  Atomic  Clocksalso responsible for the fact that all
computers with built-in clocks are
The reason all atomic clocks show the samesynchronized and accurate and keep time
time anywhere you go is because they don'twhether on or off. With such accurate time
each have their own cesium atom - this wouldkeeping and the use of GPS, you can be sure
be impossible because it's incrediblythat your atomic clocks will let you know
expensive and requires very preciseexactly what time it is, down to the
conditions. Atomic clocks are actuallynano-second!
receiving the time from a shared location



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