You're traveling thru space at the speed of light. It gets dark. So you turn on the headlights. Do they do you any good?

Sadly this question and all others about experiences at the speed of light do not have a definitive answer. You cannot go at the speed of light so the question is hypothetical. Hypothetical questions do not have definitive answers. Only massless particles such as photons can go at the speed of light. As a massive object approaches the speed of light the amount of energy needed to accelerate it further increases so that an infinite amount would be needed to reach the speed of light.

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I would say, no. I am waiting for anyone to dispute me with definitive proof.

Heehee fjohn - well, I would say, yes, it still would do some good.

If you travel at the speed of light and, hypothetically, the headlights do not project forward in space but rather behind you, then at least you could look in your rearview mirror and see where you've been. Or, if the light travels with you, then you could light up the interior of your vehicle/spacecraft to read your map.

At the very least, the headlights would warn oncoming alien space traffic that are driving/flying towards you and that is a good safety measure - kind of like daytime running lights.

But seriously folks - no disrespect meant to your question hearburn, just having a bit of fun. TexasJoe is correct in that any answer would be hypothetical and not possible to answer.

Nope sorry but I have no answer for you - although it is a very interesting question. But for a lighter view on travelling beyond the speed of light you should check out out the episode in the first series of Red Dwarf 'Future Echoes'. They add a very interesting twist to it all!!

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"Depression is merely anger without enthusiasm..."

Astrix, you posted a very interesting reply which begets other questions: If the lights were pointed behind the vehicle, would you be able to see where you have been in the rear view mirror?

My question is, would you be able to see light at all? Since most light we see is reflected, wouldn't light disappear before it could be visible in the mirror?

As far as warning oncoming traffic with headlights, they wouldn't see you and you wouldn't see them if one of you were traveling at the speed of light. Neither would your proximity to one another be detectable.

My brain is beginning to hurt, so I will say no more.

'There was a young woman named Bright
Who could travel much faster than light.
She departed one day, in an Einsteinian way,
And returned on the previous night.'

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Gunslinger
'Flying itself is not inherently dangerous, but it is terribly unforgiving of any carelessness, incapacity or neglect.'

Nice poem, Gunslinger. A discussion of the properties of light and it's absolute speed can become so esoterical that a bit of whimsey and levity are always welcome.
I read in the paper a week ago, or so, about a university scientist increasing the speed of light using Argon gas and one of those scientific contraptions that only scientists understand. My science (math) knowledge is limited to balancing my check book.

You can balance your checkbook, John?! Sheesh, you mathematics wizards amaze me. I wait and see what the ATM tells me - every so often we come together on numbers.

Actually I really did learn Celestial Navigation (way back when we had to watch out for dinosaurs crossing the runways.) Yeah! I really did! Worked with an E6B and a slide rule (a what?!?). Heavy math on that stuff. Gave me gas. Soon after that, we started in on SAGE, which you may remember. Then on into INS (GPS came after my time, but I'll sure use it today. haven't picked up an E6B in years and I have no idea where my slide rule is. How decadent we get.)

This was an exercise in how far off topic we can get.

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Gunslinger
'Flying itself is not inherently dangerous, but it is terribly unforgiving of any carelessness, incapacity or neglect.'

NO. You're headlights would not help you.

It's been a very long time since I took General Relativity and, needless to say, I sure haven't used it on a daily basis, but I seem to recall that problem being posed in class. If I remember correctly, the answer was that the speed of light is a constant regardless of your frame of reference, even if your frame of reference is moving at the speed of light. So, I THINK the answer is that the light from the headlights will propagate at the speed of light out in front of you eventhough you're traveling at the speed of light. At least I think that's correct. That sounds paradoxal, but then relativity is full of paradoxes, so I may be recalling the answer correctly.

Gunslinger: I saw a slide rule in a museum once. Kidding. But, actually the precursor to the modern nerd was not just his pocket protector with the pens lined up, it also included a slide rule. I remember a math teacher trying to tell me to line up the C scale with the D scale, or some such nonsense, and extrapolating an approximate answer from the results.
Boy, am I glad that Texas Instruments later made a calculator that I could afford.

By the way, your poem is probably a limerick, if there's an Irishman out there to confirm.

[This message has been edited by fjohn (edited 09-08-2000).]

Yeah, thank the gods for good ol' TI. Trouble is with that, ask a High School or college undergrad how they handle their math problems when their calculator batteries run out. Can the young folks actually calculate the way we had to? With a pencil and paper? Took ages to write out and extend the equations, I grant you, but we COULD do the problem. And we could do much of it in our heads! If today's young folks can't extrapolate without a calculator, today's education is in serious excrement.

Getting back on track with our light-speed problem: (the differential calculus can be done on a chalk-board, or pencil and paper. Can today's youth do it? I hope so, because it's very helpful having all of your calculations up there and visible when you're trying to find an error.)

It's a mathematical problem, like most others. Humankind will keep at it and will likely solve the problem eventually. And when the answers come, down will go the vast majority of the crackpot theories and former 'absolutes'. The solution will apparently involve temporal mechanics as well, since time seems to play a part in trans-light speed (vis-a-vis 'Star Trek's' 'Warp Speed'. NOT a particularly crackpot idea - seems based upon real potential.)

Einsteinian relativity, if not the whole answer, seems to be the starting point.

Ah, well. Differential calculus can give you gas, as I noted. I was never geared for high mathematics. Hated it, in fact.

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Gunslinger
'Flying itself is not inherently dangerous, but it is terribly unforgiving of any carelessness, incapacity or neglect.'

[This message has been edited by Gunslinger (edited 09-08-2000).]

Re calculators vs. pencil & paper:

I once heard that you can tell the "old" generation from the "new" generation in that when the "old" uses a calculator they confirm the answer by working it out on paper; while the "new" generation may work it out on paper but confirm the answer with a calculator.