theoretical speed of light question

[nathansphase]

If you're in a vehicle going the speed of light, what happens when you turn on the headlights?

[Elizabeth ll]

The speed of light is 196,000 miles per second, it is the mathematical measurement of one point to another. Your headlights have nothing to do with it,lol lol, At that speed i doubt they would even work,lol lol or you would have a car left,lol lol.

[nathansphase]

Maybe I need to be clearer lol,headlights produce light so say they managed to work as your vehicle is travelling at the same speed would they appear on or off?

[Elizabeth ll]

Oh, sorry, I,m too practical sometimes, lol. I,m going to ask my brother that question if you don,t mind, he is a near genius. Good question, I would imagine they would appear off myself. If you have the answer I would love to know, always curious.

[mibn2cweus]

First we need to answer more fundamental questions like, "What caused the Big Bang?" Just reaching the speed of light in your vehicle ought to do it!
Never-the-less, contemplating and seeking the answer to such questions can be instructive and intriguing . . . provided you have nothing better to do with the rest of your life . . .

D'oh! ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ <o/�\o>

[fo3nix]

The answer is void, since the question makes no sense.

No massive object (and by that I mean object with mass) can travel at the speed of light. Hence, your vehicle can't travel at the speed of light.

However, you can imagine that your vehicle is travelling very close to the speed of light (but just less than). In this situation, turning on your headlights would result in your light beams travelling away from you at the speed of light, as usual (assuming you're sat in the car).

[John89]

The person above is correct. The light would appear to you in the car to be moving away from you at the speed of light (3x10^8m/s). However to someone outside the car the light from the headlights would only move at the speed of light relative to them rather than double the speed of light as you would expect..
This is due to the special theory of relativity.

[jake-the-peg]

This question often draws the response that nothing with mass can travel at the speed of light.

OK change the question - to what if a mass-less particle travelling at the speed of light emits a photon.

But wait a minute - the emission of photons is associated with charged particles - an accelerating charge emits radiation, an electron jumps shell and emits a photon.

There are no mass-less charged particles, sure there are massive particles that are neutral but no mass-less particle has an electric charge.

I suspect there is a deeper significance to that

[nathansphase]

to say nothing travels at the speed of light with mass is untrue the starship enterprise does and even faster than that ! it must have a mass of several million tonnes

[fo3nix]

Yes but we were under the impression you were talking about reality.

[squarebear]

I think the fact that he is discussing travelling in a vehicle with headlights at the speed of light means reality has long gone out of the window.