ive always been into space n all stuff associated with it, tried reading S,Hawkins 'brief history of time' and understanding all the strange wonders of the universe. As sad as it seems i find it fascianating , at the moment im trying to get my head round spacetime , i.e time and space are seen to be as 1 , a 4th dimension . the speed of light is constant no matter how fast your travelling , it will always travel away from you at the speed of light. Even if your near that speed yourself. I understand that what we see and experience is relative. I,ll give you a small example in Hawkins book.

Sitting beside the rail track you witness a train travelling at say 100mph , 2 people playing ping pong on the train. Being at the side of the track you see this game and witness lets say 30 yards apart from each time its hit as train passes. The ball would also being travelling at 100mph like the train. And you,d be correct for your observations.
You,d also be correct in saying from a player point of observation that the ball is only travelling a few feet between shots and is at a 0mph (imagine a stationary ball on table for a sec) and your correct too for the same amount of time as seen at the trackside.
A brilliant example of relativity , you will percieve the same event with different results in the same time but both be correct!

Im struggling to get this idea on a bigger scale as its hard to think about . time itself , and the fact you will age slower the faster you travel??? (think thats right) anyone else a bit of a geek for all this , yes ive had a beer hehe

Mike