I'm impressed with most of the thoughtful responses to the "hydrostatic kill" (gag) thread... so I offer this.

If there is such a thing as a favorite question, this is mine.

You may NOT "interpret" this question into asking for information other than what is requested. This restriction, in itself, should stop 99% of you COLD. The rest of you, however, who have brains and can address "THE QUESTION" -- you may proceed.

A car is traveling at the speed of light.

The driver pulls on the headlights.

Question: Do the headlights illuminate -- and why, or why not?

You must show your work.

Enjoy.

Russ

The speed of light is finite, but it is the same to all observers.

So the answer is yes.

Canuck

To be clear, however, the car never could reach the speed of light. Do to the equivalence of mass and energy (e=mc2), for the car to reach the speed of light its mass would become infinite and it would, therefore, require an infinite amount of energy to propell it. Only light or other waves with no mass can move at the speed of light.

Stephen W. Hawking is one of my favorite authors.

Canuck

[ 12-01-2002, 08:56: Message edited by: Canuck ]

Oh Jeeze, Chris took the words right out of my mouth! Way to go, Canuck!

If the car's mass becomes infinite at the speed of light, it will become a black hole at warp one.

Light will not be able to escape or be emitted, hence the headlights will not illuminate.

Neutronium baloneyum!

Those of us on earth might still see the emittance of particles and radiation (like those emitted by a hot body) from the black hole though!

Canuck

umm, who cares. at that speed my truck gets real shitty miliage and I cant afford it.

No!

What the driver pulled is actually the cigarette lighter, the light switch requires a twist on the signal arm..

DUH! Light has mass. It is bent around massive odjects by gravity.
Yes there will be light, the source is moving.
However it will be red shifted to the extent that it would not be visible to an observer, unless they are positioned far enought to the "side" of the movement.

And for my next pontification, I will explain why Cliff Clavin should be the ruler of the universe.

The black holes that emit are not of infinite mass. It only takes a finite mass of neutronium to make a black hole. The emissions we see may be due to phenomena such as collisions and fission/fusion occuring as mass is sucked into them, and due to their rotation, creating the pulsars or quasars, as they spin and suck.

The red shift would be down to zero hertz on the tail lights, but since the head lights cannot emit at light speed, I guess there is no concern about blue shift.

The lights would not emit on that car, neither heads nor tails.

I want one. Those Kentucky cops would have a tough time catching me for speeding in one of those, especially at night!

Now, how about the dome light in that car? Oops, never mind.

What are they gonna do, send me to Nam?

[ 12-01-2002, 10:44: Message edited by: craigster ]

A black hole of truly infinite mass would cause a universal singularity, the big crunch, would it not? So, if I am not mistaken, all black holes have a finite mass.

The radiation emitted by a black hole depends only on its mass. The larger the black hole, the lower its temperature.

The radiation comes from the existence of particle pairs that appear in space, exist for a short while and annihilate each other. On the event horizon of a black hole, one of these virtual particles may be trapped in the black hole, while the other is free to escape into space, appearing to have been radiated by the black hole. After this, I am going to have to go dig out the book!!!

Now, if a 10pt buck was on one side of a wormhole and you were on the other, what caliber would you use? Would your choice differ if you were on one brane, and the deer was on another?



Canuck

[ 12-01-2002, 11:07: Message edited by: Canuck ]

Down here in Venezuela the lights would not illuminate when he pulled on the headlights. The locals never replace their beams. Travel at the speed of light however is normal here.

A corollary to the above is that the traffic signals do not illuminate either, possibly because we approach them at the speed of light; or they are ignored anyway, so they don't maintain them.

Physics and Math, as we know them, don't apply here.

The companyman on the rig called early last week asking about the possibility of getting a pumpkin pie for Thanksgiving. I had to order three pies.

It cost one pie to get the pies from Maracaibo to Ojeda. (The Transito Police and Guardia Nacional take their cut along the way.)

I got family staying with me for the holidays so that's one more pie down the tubes.

The last pie was cut in eight pieces. The maid got one. The guard on the apartment gate has to be kept happy (1 piece). The dispatcher and guard at the dock each got a piece. The launch captain and mariner each got one. That left two pieces of pumpkin pie for the rig. We have a Value Added Tax here (IVA) that amounted to four pieces. So the rig owed me two pieces of pumpkin pie.

It's a shame. I ran the same scenario using four and five pies, and the end result is always the same. The math just works differently in South America.

One of my co-workers is a black hole and the light never comes on in that singularity.

And my dad tried that in a '59 Caddy but the dash photo sensor kept the lights off.

So I vote for no light.

Sorry Russel, never got into Relativity but you sure brought the comedians out of the woodwork. Good on ya!

I think Russ is laughing his ass off at the fact we respond to any damn question at all.

I just got sucked into that black hole...here goes nothin'

Albert said its all relative. He says (we have beers together every now and again) that it cannot be proven that the observer is moving OR not. Hence its relative. The whiteknuckled driver would see the headlights because he is still and all the universe around him is moving at the speed of light. Same as the passenger on the train who walks forward.

put the crack pipe down and back away

I put sugar in my morning coffee, what are you guys putting in yours????

Actually, the line was that in Vietnam, Charlie owned the night.

Anybody got stealth technology on a black corvette yet? That could be bad in the wrong hands. Of course it would be perfectly safe if I had it.

Sure they would "come on", but if the car is traveling at 186,000 miles per second, and the lights, even though on, emitted light at the same speed, they would not shine out beyond the car... same as a jet going at or above the speed of sound, which is a function of temperature and not a "fixed" figure. If the airplane is above the speed of sound, the sound itself gets to a given point AFTER the aircraft has passed. Another example is looking distant objects through your telescope. In many cases, you are looking at light that is thousands, or millions of years old. The light that is currently hitting your eye, left the distant object thousands and thousands of years ago...And, there are objects that can be observed through the telescope, that have actually already burned out... but since the end has not reached here yet, we can still see the light. In looking into distant space, we are actually looking at distant history. There is a theory that if we could "catch up" to light emitted from earth millions of years ago, we could theoretically look into the past ages... There, that will teach you to ask an old airline pilot (and amateur astronomer) a question like that...

Quote
"Actually, the line was that in Vietnam, Charlie owned the night"
NOT WHERE US NAVY SEALS WERE DEPLOYED!
Jeff

Einstein's THEORY of relativity... its a theory and thats his whole point, it cannot be proven. Hence the term RELATIVE. No matter how fine a measurement you take there is no end to it, its infinate. In this question it pertains to motion or lack of it. Therefore the car that is travelling at the speed of light is SAID to be travelling at the speed of light from or to an observer that is SAID to be still. This is what Albert meant by RELATIVE.

Heres the crazy part. You are the driver and you turn on the headlights. Big deal, you may as well be in your driveway, they shine out the same. The only difference is that YOUR WIFE (the observer) is moving away from YOU at the speed of light. See, it depends (its RELATIVE) on who CONSIDERS themselves as not moving. If you thought that you were moving and you pulled on the headlights and saw them then she MUST be moving not you.
Remember, we already agreed that we cannot prove perfect stillness so we SAY we are.
Now are you confused yet? Good 'cause here's the haymaker. Einstein said that if you accept this crazy ability of light (speed cannot depend on the motion of the observer or source) as proof (not theory) then and only then will all applicable experiments have the correct results.

Russ, he couldn't prove it so how the hell can I?
I'm going to take his word for it.

Einstein had a theory called "relativity" that showed the lights will indeed illuminate. It is a theory and has yet to be proven one way or the other. That's the best I can do.

Signed
Mental Midget

Well, I'm inclined to think that from the "moving-with-the-car's" observer's perspective, the headlights will NOT illuminate. In fact, at all points in front of the car, they would not illuminate. Yes, I think they would be powered with electricity but, by the time any "light" emitted from them, say at Point X, the car would now be at a new point, Point Y, and the lights would NOT be "on" at Point Y. Back at "the old" Point X, I think "light" would be seen. So, if you're riding on the hood of the car (and I've done this, but not at the speed of light), I don't think you would see any light coming from the headlights.

Now, if you really want to get sticky about it, consider that electricity travels at the speed of light and that you have to consider the circuit through which said electricity would have to pass, once the switch was closed, to provide power to the headlights. I'm not sure if this would be a factor with which to contend or not, but it does require additional aspirin.

Russ

In Pakistan the only two things an automobile must have to be considered road worthy are an accelerator and a horn. All other controls, devices etc are optional. So to answer the question...the lights would only be visible if Allah willed it...
I haven't done a length contraction/time dilation calculation since one of my college phsyics classes. And even then I still had a tough time with simple vectors. Russell..you make my head hurt!

Russell, I been a studyin' bout your kwestion and I think it's one O them trick things. You never said if it wuz night nor day in your example. And everbody knowz your headlights don't I-luminate shit in daylight! So the answer to your question is: "That depends on twether it uz night or day when this feller pulled on his lights. And I reckon it also dependz on thwether there wuz anything to
I-luminate after he got um pulled on."

You may a fooled these youngin's but you got ta get up pretty early to fool the Ole P45! Har,har,har.

Personally I don't know of no roads around my parts where a feller could get his pickup much over 45 mile a hour and stay on the road for long. Besides, mine has got such a shimmy at around 35 that I generally hold it at 30.

Now, I got a kwestion fer you? How come you ain't down to the PX drinking 3.2 beer like I done when I wuz in the Army?



[ 12-03-2002, 08:43: Message edited by: Pecos45 ]

Yes, the headlights illuminate. They illuminate the same as they would if the car were standing still. At the speed of light the car becomes light to the standing-still bystander but not to the occupant of the car. The car occupant also ages much slower than the the bystander.

What a stupid kwestion

Here is a better one.
If a women is flying upside down in an airplane will she have a hairy crack up?

And another>
What color is Relative bearing grease???

And another>
Do illiterate people get the full effect of Alphabet Soup?

One more>
If something has a lifetime guarantee will it stop working when you die?


(Thanx Elkhunter)

Gentlemen,

I have learned absolutely nothing about relativity, the speed of light, etc from this thread. But I have sat here laughing like a boozed up fool. Thanks, I needed it this morning

Lynn D

........Now my head hurts, thanks Russ!

Great post, Spectr17, loved it!

Russ

If anything was infinite wouldn't that mean that it compossed absolutley everything in existance?

If your doing 55 mph and throw a baseball 55 mph out the window straight ahead will it leave your hand? Yep I tried it. With a beer bottle at a road sign though. I missed.

Good point, Markus. I've thrown a lot of beer bottles at roadsigns and don't recall for sure if I ever hit one.

However, I did have a roommate in college who was quite gifted at the beer bottle throw and seldom missed.

I've often thought this would make a good olympic event.

I got pretty good at the beer bottle throw. Funny though, I could only ever connect from the drivers side, throwing over the roof of the truck. As a passenger I couldn't hit squat.

Markus, you are right about infinity. That's why physicists hate equations that result in infinities, and why you couldn't ever have a car travel at the speed of light.

But I still maintain -- if you could drive a car at the speed of light -- the driver would see the lights of the car illuminating objects in front of it. That is because of the very cool law that the speed of light is exactly the same for every freely moving observer, in every direction (which really messes up the traditional concept of time!)

Russ, how come you never addressed the original question? I was hoping this would turn into serious discussion too. Did you think I wasn't serious? Am I wrong?

Canuck