If a car is traveling the speed of light and turns on the headlights do they do anything?

Answer 1

First, getting a car to the speed of light would be quite a task.

Assuming all worked well, the lights would come on. Let's suppose you are down the road a bit and watched all this taking place; what would you measure to the the speed of light emanating from the car headlights?

Before Einstein, people would have said 'well, the car is moving at near the speed of light, and it turns on lights so that light is leaving the car at the speed of light, and that light must be coming toward me at almost twice the speed of light'.

Such thinking works well for low speed situations (a car is traveling at 30 mi/hr, someone in the car thrown a snowball out of the car in the direction of the car, the unhappy person hit by the snowball measures its speed to be 30+the speed it left the throwers hand).

however, that is not really how speeds add up (they just seem to in the low speed limit). Einstein showed that the way the two speeds really add up is not the simple v1+v2, but the more complicated (but accurate)

[v1+v2]/[1+(v1v2/c^2)] where c is the speed of light

so using this equation, lets say you are moving forward at c, and fire photons also at c:

I measure the photons to be traveling at:

(c+c)/(1+c*c/C^2)=2c/2=c

As Einstein showed, the speed of light is the same to all observers everywhere.

Answer 2

If, (impossible), the car is traveling at the speed
of light, there is no way to 'turn the headlights on`
because the car experiences no time in which to do it.

Answer 3

Setting away the scientific way to answer, I would like to ask you a thing that is more meaningful as,

If the car is at the speed of light then where you could position yourself to check what happens to observe and confirm to us?

It is wrong and totally meaningless and foolish to accept a CAR to travel at the speed of light! The photons which are of zero mass travels as light at that speed of 3,00,000 kilometers per second!

Answer 4

no, nothing happens.

Answer 5

Well, a car could not ever reach that speed. Due to an increase in relativistic mass, it would require infinite energy to reach c.

However, let's say you got really, really close to the speed of light - say 99.99% of c.

Relativity states that the speed of light is constant in all frames of reference. This means that to a passenger in the car, the headlight beam would move away from him at exactly c relative to the car, so he might figure that a "stationary" observer would see a beam of light travelling at almost twice the speed of light.

However, he would be wrong. To the ground observer, the beam of light would still travel at exactly c from HIS frame of reference. To him, the difference between the speed of light and the speed of the car is only 0.01% of c.

How can this be? There appears to be a paradox. Relativity addresses this by a phenomenon called time dilation. The passenger in the car percieves the passage of time much more slowly than the observer on the ground. The differences in the perception of time is exactly enough to account for the apparent difference in the speed of the headlight beam.

Answer 6

Yes, the light would travel at it's usual velocity of c, 3x10^8m/s. Relative to the driver of the car, the light would seem to move as it does when at rest. The speed of light is not relative to anything, so it seems to move the same.

Answer 7

Maybe you mean a light source travelling at the speed of light since cars cannot nor will ever travel so fast. The emitted
light will frequency-shift, possibly crossing a barrier as
another form of energy.

Answer 8

I think not.....I know not

Answer 9

Well, nothing can go as fast as light, so I guess not

Answer 10

They would technically be on but they wouldn't be shining in front of you because the headlights and the car would be travelling at the same speed.