Physics education research, electronic materials, and the musings of Christopher Moore, Ph.D.

Me and a friend were just chatting about the speed of life.   Can someone tell me what would happen in the following thought experiment?

A beam of light gets fired down a tube, one light year long.  It's fired so that it bounces off the sides of the tube millions of times before it reaches the end, so the light travels two light years.

How long does it take to reach the end of the tube?   How fast is it going?   What would these four different perpectives be; someone watching from the start of the tube, someone at the opposite end of the tube, a theoretical person travelling at the speed of light alongside the tube, and a person travelling with the light beam?

Any answers enormously appreciated.

Cheers!

Last edited by jugglia (2008-12-17 19:22:26)