Index Key:  PHY069
Author:     Mark Bradshaw
Subject:    Light speed and lasers
Text:       I was wondering perhaps if a person was traveling in a starship at 
the speed of light, and a laser was fired in the direction the ship was 
traveling, would the laser travel at two times the speed of light?

Response #:  1 of 1
Author:      A. Smith
Text:        I think some questions similar to this have already been asked, 
but first of all, "time distortion theories" are rather important, if you are 
interested in starships that travel at the speed of light.  Unless they obey 
some laws of physics that humans have not yet discovered, nothing that has any 
mass can actually travel at the speed of light (it requires infinite energy).  
The laser would head off ahead of the ship, at the speed of light, exactly.  
Actually, light can effectively be traveling a little slower than the speed of 
light, if the medium it is traveling in is not a pure vacuum, and so 
interesting shock wave effects might happen (just like a supersonic plane's 
sonic boom) if the spaceship happened to be traveling faster than the speed of 
light in the medium there.  But light cannot travel faster than the speed of 
light.