Recent content by fast_squirrel

I think that the center of mass is not fixed in Relativity (unlike in classical physics). Could anyone look at my attached memo and tell me if I am right or wrong.

I like this answer, but do you , or any one, knows how to demonstrate it ?

Ok, but this does not imply the impossibility of a particle coming from the cosmos and going faster than c

Thanks for the answer using the Maxwell equations. But still, the next question is : Why can't any object move at a fatser speed than the speed of light in the vacuum ? Thank's in advance,