>I have long been wondering; If you are driving in n automobile that is
>traveling at the speed of light, what happens if you turn on the
>headlights?
>>Please tell me what you think would happen. If I don't get an answer,
>then I'll assume that none of you really know.
>
This is a dubious forum for this question, but I can't resist giving a
serious answer.
First, a car, or any other object that is not composed soley of
electromagnetic radiation, cannot travel at the speed of light.
But suppose the car is travelling at 99% the speed of light?
What happens is that the lights of the car go on. The light travels away
from the car at the speed of light. An observer in the distance sees the
light approach at the speed of light.
The speed of light is constant regardless of the observer's frame of
reference. This is a fundamental assumption of Einstein's theory of
special relativity. Many experiments to test it have been performed and
found to be consistent. The fact that an object with mass cannot travel at
the speed of light is a corollary.
Dave Merberg
Research Computing
Genetics Institute
(amateur astronomer wannabe)
