The fact that
the speed of light is the same in all reference frames
has the consequence that moving clocks run slow. This
means that if two events occur at the same place, such as
the ticks of a clock, a moving observer will measure the
time between the events to be longer. The relation
between a time measured by a stationary observer
is: vThe gamma factor is
common in relativity, and we will use it often. It is
always greater than unity. If the velocity were greater
than This result can be
shown to result from the fundamental postulate by
considering a The time between ticks and tocks for the stationary clock is: One can now view the
same clock as it moves past with velocity The time between ticks
and tocks is again given by the distance traveled by the
red pulse divided by Solving the above
equation for ,
h and v
givescThus the moving
observer sees a longer time by the factor |