# What would happen if you are traveling the speed of light in a car, and then turn on the head lights?

would you be able to see light in any direction. would the light never exit the head light covers, what if you traveled slightly faster then the speed of light. could you see the light in your mirror behind you??????

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Don't feel bad, it's a valid question. The weird thing about light is that it moves at the same speed no matter what frame of reference it is being observed in. In this case, the light shooting out of the car's headlights would be moving as fast as the car, so it would be impossible to actually "see" it from inside the car. Outside the car, there would be no perceivable difference.

Remember that to see light, you need to have it reach your eyes. If it were possible to go faster that light, you'd never see the light behind you because it would never reach your eyes.

These would all be very unfortunate circumstances because if they were possible, the warping of space and time at the speed of light would cause you to travel infinite distance in an infinitesimal amount of time. This is why you shouldn't ever ride a bike (or car) at 300,000,000 m/s.

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• You can't go AT the speed of light. Things that do so go only at that speed, never faster and never slower. If you're going at ALMOST the speed of light, and you turn on the headlights and measure the speed of the light that comes out from them, you'd read the same speed of light that you'd read if you and the car were standing still. Many people know that moving at some speed relative to the observer (hence the "Theory of Relativity") causes changes in the mover's length, time, and mass. (The equations that describe the changes are called the Lorentz transformations.) "Speed" is, after all, length per time. As you move closer to the speed of light, the changes in your length and time work out in such a way that the length-per-time of the light from the headlights comes out to be the same value of length-per-time as the sitting-still value is. So you'd measure the same speed of light from those headlights at any speed you were going.

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• Nothing, time stopped.

At c time stops.

Thus:

velocity = distance/time

Distance = velocity * time

(We know that light has a non-zero velocity = If photons are not moving with respect to the ship (distance = 0) then time must = 0)

The photons would be traveling at the same velocity as the ship, so they are motionless with respect to the ship as observed by an outside observer.

An observer on the ship sees the photon moving at c but since time has stopped, the above is true.

Imagine a "photon clock"

The person traveling at c is in a transparent space ship exactly 1 light second long. There is a perfect mirror at each end of the ship with a photon bouncing back and forth between the 2 mirrors. Each time the photon hits a mirror the clock ticks one second. Now take the ship to c.

tourture

The observer can see the photon just as it bounces off the rear mirror. Since the ship and the photon are traveling at the same speed (c) the photon appears to be motionless with respect to the ship (and going c with respect to the observer’s frame of reference. Think of 2 cars side by side on the highway both going exactly 60 km/hr. Relative to each other they are motionless. Relative to the highway both are going 60 km/hr). In effect, time has stopped; the clock will never tick again.

That clock is dead accurate for the frame of reference it is in.

Whether or not time is passing depends on the frame of reference. For the Photon on the ship time has stopped and it is not moving with respect to the ship. For the Photon as observed from outside the ship, time is still passing and it is moving in that frame of reference.

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• I would think the speed of the light leaving the headlights would be increased by the speed of the car, and would go out in front of you. I'm not sure what you would be able to see in the headlights at that speed, not even sure what the light energy would do when it tries to reflect off an object at that speed. You should be able to see light in any other direction, except directly behind you. But it would probably be distorted images, due to the bending of the light waves as you travel through them. Like sound, the frequency would change as you move, like a train when it passes. It'd be interesting to find out. Maybe it would be like a painting, smeared. The old belief that the speed of light is the maximum speed attainable was proven false years ago. Just as the speed of sound was once thought to be the barrier, light speed can be passed. Think of an enormous wheel turning slowly at the center. The outside edge, if the wheel is big enough, would be able to move faster than the speed of light. It may be there are galaxies turning at a speed and size to prove this, but how to see and measure it?

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• Anonymous
10 years ago

at the speed of light, all laws of existence and science don't function properly. Theroretically (as this truly is impossible), the light from the headlights would be thrust forward at the speed of light.

Basic laws like 1 + 1 = 2 are null and void at the speed of light.

So, if 'c' is the speed of light, c + c = c.

It's a similar idea to if you added infinity + infinity. This equal infinity. I'm in no way implying that the speed of light is infinite, however it does take infinite energy to move anything with mass at the speed of light. If you apply an infinite forward force on and object that already has infinite forward momentum, the result is an object with infinite forward momentum (no change).

yes, this means 1+1=1, but you're moving at the speed of light, so all of physics and mathematics is incorrect as it is.

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• The emission of light from an object, independent of the object's speed, consists of a photon of radiant energy becoming separated from the matter in your car. It's mechanism of release is independent of the speed of the car. It enters into a state of propagation of 3x10^8 m/sec. Because of the principles of relativity, this will be the measured speed of the photon not only to you in the car (e.g., time dilation) but also to someone sitting on the ground watching. If you and the car achieved the speed of light, all of the matter in you and the car would have converted into radiation. The speed of radiation (speed of light) is fixed.

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• You are asking the most cliche and idiotic question of this category.

Bodies of ordinary mass CANNOT travel AT or FASTER than the speed of light. Either would require infinite energy.

From now on, BE EDUCATED and ask about 99. however many nines you desire % of the speed of light.

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• Anonymous
10 years ago

then you would have one hell of a speeding ticket

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