Oct 25, 2011
It’s just gone 5:30 on an autumn evening here in sunny England, but where you are it might be later in the day and already dark, or in the opposite hemisphere you may have only just woken up after a good night’s sleep. So, time exists, but for the Earthbound it’s not the same for everyone. Now, imagine you’re sitting on a GPS satellite, what time is it there, given that relativistic effects certainly take place when one object is accelerating relative to another? What time is it on that satellite as observed from terra firma? What time is it on the Moon, or that distant planet orbiting two stars? And, when we talk of once upon a time in a galaxy long, long ago, we really do mean a long time, the light from some distant cosmic objects is yet to reach our telescopes, light from objects that appeared not too long after the Big Bang have just hit the sensors…so does time exist or not?