If a car travels at the speed of light and turns headlights on what happens?

[size=-1]First of all, you need to realize that when you say you are traveling at the speed of light, that has to be with respect to, or relative to, something else. It is an underlying fundamental assumption of Einstein's special theory of relativity that uniform, non-accelerated motion has no meaning of and by itself. That is, there is, by assumption, no meaning to the idea of moving uniformly at the speed of light in an empty universe. That state is completely equivalent to being at rest in an empty universe..

I preface my answer with this comment because it leads immediately to the answer to the question. Imagine that you are in your car 'traveling at the speed of light' and that you turn on your headlights. That state of motion is utterly equivalent to being at rest in an empty universe. Since, when at rest, the light from your headlights would be launched forward from your car at the speed of light, relative to you, with a certain color spectrum, that is exactly what would happen if somehow you could be moving instead at the speed of light.

In other words, the presence or absence of other objects or matter in the universe relative to which, if present, you could make a determination that you were moving at the speed of light makes absolutely no difference to your own experiences and experiments. The light that you launch behaves in exactly the same way whether the other referential matter exists or not.

This leads into another interesting question, however. And that is whether the rest of the matter (mass) in the universe in some way affects your own local observations. So far this question has come up in relation to theories of gravity. If effect, the question is how does the universal gravitational constant, G, which determines how strongly gravitating masses attract each other, know what value to assume if there is no other mass in the universe. Mach proposed, essentially on philosophical grounds, that G must be determined by the sum total of all of the mass in the universe. Einstein assumed in his General Theory of Relativity that G is simply a universal constant, independent of the specific mass distribution of the universe. On the other hand, Brans and Dicke later proposed a so-called scalar-tensor theory of gravity in which the local value of G depends upon the rest of the mass in the universe through an additional scalar field that does not appear in Einstein's theory.[/size]
Click to expand...
 
If the light was already on before reeching the speed of light then it would light up as per normal.. as some light would already be ahead of the car. But if turned on upon reaching speed of light.. nothing?
 
there wouldnt ever be light infront of the car. the lights would be on but it wouldnt project anything bcos the car is going the same speed as the light???


EDIT: just thought about it and nothing would happen ... thats so confusing i dont know
 
The flies and bugs you hit would destroy the bulbs anyway so it's all academic (besides the fact the speed of light is rather hard to reach and travel at :p)
 
StevenG said:
there wouldnt ever be light infront of the car. the lights would be on but it wouldnt project anything bcos the car is going the same speed as the light???
Click to expand...

The speed of light is constant!! So even traveling at the speed of light the light from the headlights would appear to travel away from the car at the speed of light.
 
Freefaller said:
The flies and bugs you hit would destroy the bulbs anyway so it's all academic (besides the fact the speed of light is rather hard to reach and travel at :p)
Click to expand...
If you can reach the speed of light, you can get sufficiant anti-bug protection surely =P?
 
You must log in or register to reply here.
Back
Top Bottom