(Submitted February 25, 2005)
Has the time dilatation been prooven in any experiments? If so how?
Effects of the right magnitude have been measured to be consistent with
time dilation to within measurement uncertainty. These are not
definitive proofs of the theory but strong indications that the theory
is correct. One experiment has been to fly atomic clocks in planes
around the Earth in opposite directions. The difference in time between
the two clocks after the flights was consistent with those predicted by
time dilation. Furthermore muons, sub-atomic particles created in the
upper atmosphere by cosmic rays, are unstable and fall apart after a
short period of time. However because they move close to the speed of
light, their lifetimes are longer, at least as seen by us on the
Earth's surface. This extended life, is also consistent with the
prediction of time dilation.
Martin Still & Jay Cummings
for "Ask an Astrophysicist"