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| NIST-F2 cesium fountain atomic clock. Public domain image |
No,
it won't be used to make sure The Angelus starts at dead on 6 pm or even
for timing sports events. The accuracy of atomic clocks has been used
to prove the validity of Einstein's Special and General Theories of
Relativity, time dilation occurring when something moves very fast or
when subjected to lower gravity. To prove the theory, clocks were flown
on jets travelling in different directions as part of the Hafele–Keating
experiment in 1971. When the clock on the eastbound jet was compared to
a clock remaining on the ground, it was found that it was was slower
than the ground-based one by 40 nano seconds. It ran slower because of
the speed of the jet, but faster because of the reduced gravity at
cruising altitude, the net loss being 40 nS. If we could travel at close
to the speed of light in a spacecraft, and could see what's happening
on Earth, everything would seem to be happening at super fast-forward
speed, while time would progress at a normal speed for us. From the
point of view of an observer viewing us from Earth, time would appear to
stand still in our spacecraft. Atomic clocks have practical uses on GPS
satellites, nanosecond accuracy giving good positional accuracy when we
use GPS to find our position on Earth. This latest clock will have uses
presumably for studying the fundamental behaviour of the Universe.
You can read about the new clock on the Popular Mechanics site here.