MadSci Network: Astronomy |
There are two answers that I can give you, and neither one will really be satisfactory!!! Answer number one: Nobody really knows!!! Answer number two: It has to do with the equivalence of mass and energy, and is basically a relativity thing.
There are, literally, dozens of previous answers on our site dealing with
relativity and time dilation. Search on the engine that is at
http://www.madsci.org/MS_search.html
searching simply on "relativity". You will probably be overwhelmed by
the number of answers, but wade through them and you will get a feel for
what relativity is all about. One of the things you should come to find is
that nobody really knows *why* relativity is the way it is.
John Link, MadSci Physicist
Try the links in the MadSci Library for more information on Astronomy.