sylvan
this is in reply regarding time dilation
Time Dilation ---> A moving clock ticks more slowly than a clock at rest.
Measurements of time intervals are affected by relative motion b/w an observer andwhat is observed. As a result the a clock that moves w.r.t an observer ticks more slowly than it does when it does without such motion and therefore such processes occur more slowly to an observer when they take place in a different inertial frame.
Explanation:-
Consider a time interval of t_0 b/w any two events in a space craft. We on the ground would find that the same interval has a longertime duration t. t_0 is determined by the events that occur at the same place in the observers reference frame , this is called proper time of the interval, but when witnessed from the ground , the events that mark the beginning and the end of the time interval appear longer than the proper time and this is called ' Time Dilation " .
the formula is:
time dilation(t) = t_0/sqrt(1-(v2/c2))
i.e.., t_0 by sqrt of (1-(vsquare/csquare)) .
where
t_0 = time interval on clock at rest relative to an observer = proper time
t = time interval on clock in motion relative to an observer
v = speed of relative motion
c = speed of light
Sampath.