Expert: Jayendra Upadhye - 11/30/2005

Question
say your in a rocket with headlights going the speed of light and you turn on the headlights, would the beams of light travel ahead of the rocket?

Answer
Hi,
The speed of light is constant (science-speak so far) in a vacuum, and if the rocket is travelling at the speed of light, The beam sent out would still be travelling at speed C only. (this speed is independent of frame of reference).

For an observer on the rocket, any beam directed forward, will not be emitted at all. as the ship will keep on catching up all radiated wavefronts / photons.

Lightbeams sent backwards, will also travel at speed of light in all frames of reference, and will appear to be extremely red shifted (almost infinite wave length or zero frequency!

In either case, 'seeing" the light will be impossible.
Jayen