When you look into a night sky you see the stars far away, 
you're seeing them because of the light which travels from 
them to you. Now it takes time for light to travel here, so 
what you are doing is seeing the stars as they were in the 
past, the amount of time it has taken for the light to reach 
us and the further and further away those stars are, the 
further back in time you are looking. Now you are seeing a 
star that is say six thousand years ago, imagine somebody 
on that star looking at us, they would be seeing us as we 
were six thousand years ago. Which of those two is now? 
So space and time are linked together. As we are looking 
across space, we are looking back in time.

-Prof. Frank Close