Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Archie on 11/05/2010 12:30:02

Title: What happens to a travelling light source?
Post by: Archie on 11/05/2010 12:30:02

Archie asked the Naked Scientists:
   
Recalling the old high school math/logic problem: "If you fire a gun off a train traveling at velocity X in one direction and the bullet is escaping the barrel at the same velocity in the opposite direction with no other external factors, what happens to the bullet:
 
Using that same type of setup, replace gun and bullet with a flashbulb, space the speed of light, etc.
 
If a flashbulb were traveling at the speed of light away from me, again with no other factors involved,  then flashed at a distance one mile from my eye, would I see the light, or would it hang in space, or would it continue to travel with the bulb, or would parts of it do all of the above, or ???????????????

What do you think?

Title: What happens to a travelling light source?
Post by: syhprum on 11/05/2010 13:04:49

I think you would see nothing as the radiation from the flash bulb would be red shifted down to zero frequency much as the light from the 'big bang' is red shifted down to CMBR frequencies.