Photon Speed when Bouncing off Moving Object

[clok555]

Ok quick question if a photon of light bounced off of a spaceship (or anything really) that was traveling at light speed, would the photon double in speed? similar to if a tennis ball hits a racket that is stationary it will lose energy but if the racket is swung towards the ball it will rebound with more energy.

thanks,
clok555

 

[phinds]

a spaceship has mass, so it is impossible for it to travel at light speed.

If a photon bounced off of a spaceship traveling at .99c, then the photon, which hit at a speed of c, would bounce off with a speed of c.

 

[Drakkith]

Ok quick question if a photon of light bounced off of a spaceship (or anything really) that was traveling at light speed, would the photon double in speed?

Nothing with rest mass can travel at c, so your question is invalid. Furthermore, light ALWAYS travels at exactly c in a vacuum, no matter what.

similar to if a tennis ball hits a racket that is stationary it will lose energy but if the racket is swung towards the ball it will rebound with more energy.

thanks,
clok555

I believe that while light will not gain or lose velocity, it will gain or lose energy. For example a solar sail uses light from the Sun to push it along, which requires that photons lose momentum as they transfer it to the sail. This causes a redshift in the reflecting light.