What happens if we drive a vehicle with the speed of light, an turn on the lights?

Question

The effect

Answer 1

you wont see the beams of light because the bulb can't emit them faster than you are going.

Answer 2

By our current understanding of physics, it is not possible for the vehicle to reach light speed in the first place. This is a consequence of relativity -- as an object with mass nears light speed, the amount of energy required for further acceleration shoots up exponentially toward infinity.

The speed of light, according to relativity, is the same value for all observers, regardless of their velocities relative to one another. In other words, if you are driving, say, 99.5% of light speed, and you turn on your headlights, the light beams will look the same; the light will move away from you at the same speed as if you were standing still.

Answer 3

As you reach for the knob the Great God Murphy slaps your hand away and says "Tsk, tsk."

You cannot drive a vehicle at the speed of light.

Matter ceases to be matter when it is traveling the speed of light, and distorts severely as it approaches the speed of light due to relativity. (I like the description that it actually shrinks, forcing the object to travel at a an even relatively higher speed just to get any headway).

Even if it is possible to travel FASTER than the speed of light, it is still a barrier and not a speed to be traveled at. Airplanes do not fly at the speed of sound; they fly faster or slower than the speed of sound. At FTL speeds it is possible that electricity does not function (being of this universe I cannot even conceive of FTL existence).

Answer 4

I keep seeing this question on here. I guess I never thought about it, knowing that we can't travel the speed of light, let alone, a vehicle traveling the speed of light and turning on the headlights!!!

Answer 5

First it is difficult to travel at the spped of light as mass increases with speed and if it is possible youll be going back in time by the theory of relativity if excluding these factors you cant see the light in front as both are travelling at the same speed and relative velocty is 0 thus u cant see the light

Answer 6

I can not believe that, out of the 18 answers here, only one came close to being right.

This is a question of frames of reference. If you are in a car travelling at the speed of light and you switch your lights on, the beam of light was move away from the car at the speed of light relative to your car. It would also be the speed of light relative to an external observer's frame of reference. This sounds like it's a paradox, how can it be? Well, here goes:

v = dx/dt

(speed = distance over time, ignoring the vectorial component of the velocity)

This is true in both classical mechanics and in relativistic mechanics. The issue here is that dt and dx are not constants, and depend on the frame of reference of the observer. Essentially, as you travel closer and closer to the speed of light, the value of a second to you slows down (although you would not see the difference, in your frame of reference a second would remain a second). Someone observing you externally (stationary in comparison to your motion) would see you begin to move in slow motion. When you hit the speed of light, time for you would stop. An external observer would see you are being frozen in time. To you, however, you would feel no different and you would still feel a second as a second. This is not conjecture, it is FACT and has been proven experimentally.

Here's the important bit, an external (stationary) observer would see you travelling at the same speed as the light, so they would not see a beam propagating in front of you. Remember, though, that for as long as they watch you, time for you isn't changing... you are frozen.

THIS is why this scenario works.

I must tell you, though, that as you approach the speed of light, your mass will exponentially increase with an asymptote at the speed of light, meaning your mass would be infinite. Remember, Force = mass times acceleration, so to accelerate to the speed of light, an infinite force would be needed. This is totally impossible and makes no physical sense. This is why no mass can travel at the speed of light.

Some scientists have supposed that mass is just 'slow energy'. Remember that the energy of a body at rest is equal to its rest mass times the square of the speed of light, or

E = mc^2

This is another indisputable FACT. According to this formula, energy and mass are proportional by the constant c^2. c^2, of course, is measured in only 4 dimentions (three spatial and one temporal), or relativistic timespace as it is usually known. According to string theory (or M-theory, if you prefer), there are many more dimentions following the same rules, so when energy/matter (let's call this substance 'cheese' for lack of a better label) travels at the speed of light in 4D, it has no mass. If this motion is shifted into higher dimentions such that the velocity in the first 4 is reduced, then the mass part of the cheese becomes applicable.

This is, of course, conjecture and there is no proof of this as yet. Nevertheless it is not in disagreement with quantum mechanics, relativity or string theory.... so it looks like a very promising theory that will, once and for all, accurately describe what energy and mass really IS.

And that's all I have to say about that.

Answer 7

Technically you can't travel the speed of light, you can only acheive 99.9999999999999999(and more 9's)% the speed of light. Even if you could be on the verge of reaching light speed and you flipped on the lights they would come on as normal.

Einstein determined that you cannot add to the speed of light, it is always constant. (ie. your car goes 60mph, light goes 670,000,000 mph.) The speed of the light leaving your headlights on the highway is not 670,000,060mph, its is simply 670 million mph). Its just one of those freaky things about light.

Answer 8

I believe it would appear that the lights were not on as you were keeping up with the light that was emitted, but accelerating a car under any circumstance to the speed of light would be practically impossible. I don't think you have to worry about this one.

Answer 9

It is all relative my friend. If you are on a train going 50 mph and you throw a ball 30 mph, the speed of the ball will be 80 mph to the onlooker, but only 30 to you.

Hypothetically speaking if you turn your lights on while going at the speed of light the lights will be going the speed of light times two; however, you will never notice the difference as again this is all relative.

Answer 10

Nothing because electricity only travels at 7/10 the speed of light.

Answer 11

No people can drive with the speed of light.
If you drive approching the speed of light, you can not turn on the light and all physical proceess will be slowed and disordered.