: Hello,

: I was wondering if someone could tell me about the ageing process in space. I have heard that if a person goes into space and travels around the world fast enough that when they come back to earth that their kids may be older than them. Does anyone know what I am talking about?

Yeah, you are talking about the twin paradox. consequence of Einstein's theory of relativity. for years I tried to think of a really easy way to explain (to myself) how Einstein pictured his (ok. our) world (with a simple math equation). He considered the speed of light constant. since velocity is the ratio of distance divided by time then for a constant velocity a change of distance must mean a change of time (v=d/t).