From Einstein’s theory of relativity Time slow down at the
massive body. Clock on the earth runs slower than the one beyond the earth (in space).
This is called Time Dilation.
Let’s understand this in simple way.as we know
that when we throw a ball towards the sky ball continuously moves up until it
lose its energy and then starts to fall because gravity slows it down .
Similarly, for example when high energy light (blue shifted-high frequency)
is emitted from the earth towards the on board astronauts, the high energy photons
(lights is EM wave) loses its energy when climbing up as gravity slows it down
and appears to astronaut as red shifted-low frequency.
Also the same when red shifted light emitted from on board
astronauts gravity pull it down and appears to people on earth blue shifted.
So, the Astronaut’s point of view they see that everything on
the earth takes longer (low frequency light reaches to them) also i.e. clock
runs slower on earth.
While the people on earth see that everything on board
appears faster (high frequency light reaches to them) also i.e. clock run
faster in space.
We also need to consider this time dilation in GPS System
otherwise the users may mislead by wrong coordinates or the difference is in
kilometers. That’s why engineers offset the atomic clock by some amount before launch
it in space to synchronize the time i.e. suppose time dilation is of 1 sec that
they set 00 on earth clock and 01 on space clock.
The same concept is also true for any biological events like
two twins one on earth and other in space. The twins in space looks younger
than that on earth even spending the same time.
Note :- here also think where does lost energy go ?? cause energy should be somewhere and must follow the 1st law of thermodynamics.
