Question

what is time dilation.​

Answer 1

☆Question☆

■》what is time dilation ?

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Time dilation is a difference in the elapsed time as measured by two clocks due to a relative velocity between them or to a difference in gravitational potential between their locations. 

■》Time dilation, in the theory of special relativity, the “slowing down” of a clock as determined by an observer who is in relative motion with respect to that clock. ...

☆ Cause of time dilation :-》 Gravitational time dilation occurs whenever there is difference in the strength of gravity, no matter how small that difference is. The earth has lots of mass, and therefore lots of gravity, so it bends space and time enough to be measured.