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Atomic Clocks
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here to see our selection of Atomic Clocks.
 Atomic
clocks keep time unlike any other clock. They have the ability to
keep time even better than the rotation of the Earth and the movement
of the stars. GPS navigation would be impossible without them. The
Internet could not synchronize without them. And, most importantly,
the position of the planets would not be known with enough accuracy
for space probes and landers to be launched and monitored without
the atomic clock.
Atomic clocks are not radioactive. Surprisingly enough, atomic clocks
work with an oscillating mass and a spring, just like any other
clock.
Definitions:
Atomic Clock -A clock that depends for its operation on an electrical
oscillator regulated by the natural vibration frequencies of an
atomic system.
Atom -The smallest particle of an element either alone or in combination
and is considered a source of vast potential energy.
Cesium 133 -An isotope of cesium used especially used in atomic
clocks and one of whose atomic transitions become a scientific time
standard.
SI Second or atomic second -The interval of time taken to execute
9,192,631,770 oscillations of a cesium 133 atom exposed to a suitable
excitation.
What separates an atomic clock from a regular clock is that the
oscillation in an atomic clock is in the nucleus of an atom and
the surrounding electrons. But, both types of clocks do use oscillations
to keep track of passing time.
The major difference between the types of atomic clocks available
is associated with the element used and the means of detecting when
the energy level changes. There are three types of atomic clocks.
· Cesium atomic clocks use a beam of cesium atoms. The clock
separates cesium atoms of different energy levels by using a magnetic
field.
· Hydrogen atomic clocks keep hydrogen atoms at just the
right energy level in a container lined with special material so
that the atoms do not lose their higher energy state too quickly.
· Rubidium atomic clocks are the simplest and most compact.
They employ a glass cell of rubidium gas that changes its absorption
of light at the optical rubidium frequency when the surrounding
microwave frequency is just right.
The most accurate atomic clocks available use the cesium atom. Cesium
atoms are stopped from zipping back and forth by laser beams, and
these laser beams reduce changes in frequency caused by the Doppler
effect.
Perhaps the most familiar oscillation frequency is the orange glow
you will see from the sodium in table salt if sprinkled on a flame.
Atoms have many frequencies, some are at radio wavelength, some
are in the visible spectrum, and some are found somewhere in between.
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