If you are driving at the speed of light and you turn your headlights on, what happens?

Question

If you are driving at the speed of light and you turn your headlights on, what happens?

Answer 1

You'd see some dummy in the car ahead of you texting while driving.

Answer 2

You'd be invisible. Your headlights would be irrelevant as you would theoretically be a constant with your surroundings.

Answer 3

they wouldn't be able to light anything in front of you unless you slowed down to let them light everything in front first, slow down for a second, then keep going and there will be an offset that will make it work.

Answer 4

You will beam up to another dimension.

Answer 5

186,000 mi per second.....nothing cause it ain't gonna happen and never will......whoooooot!

Answer 6

Well traveling AT the speed of light is a problem. Not only is it impossible, but it screws up the relativity equations. Let's assume you're traveling CLOSE to the speed of light. Then things get weird, but you won't perceive it. The thing about light is that it always travels at the speed of light relative to EVERYTHING, even you. To enforce this reality the passage of time must change. From your perspective the light would work the same as if you weren't moving at all, and from the perspective of a stationary user it would look like you were doing everything very slowly. When you stopped you'd have to set your clock because it would have lost considerable time.

Answer 7

READ THE COMMENTS, THIS ANSWER IS WRONG (but not irrelevant).

Disregarding the inability to do so, traveling at the speed of light would look similar to the Doppler effect with sound. Remember all those pictures of a plane and with misshapen waves? Instead of being sound waves, the waves would be light waves (yes, light is also a wave--it has wavelength).

Answer 8

You could see at night .

Answer 9

Then the cops would see you and probably give you a speeding ticket.

Answer 10

Hmm! I'd dare to say you are wasting your time!

Answer 11

First of all, you cannot travel faster than light travelling through a vacuum. This is because, even if you could get up to 299,792,458m/s, Special Relativity says that your mass increases exponentially near c (symbol for the speed of light). However, light travels slower in different mediums, such as water and glass. Therefore, you could travel faster, or as fast, than light if the light travels in a denser medium.



Einstein also said that the speed of light is constant to all observers, meaning time within the spacecraft would slow down relative to an outside observer. In short, you would see the light travel normally and the outside world will look sped up, and the outside world would see you traveling near the speed of light but slowed down.

Answer 12

Your brain wouldn't be able to see because if your brain is too slow to notice anything at the speed of light.

Answer 13

if you are traveling at the speed of light then you can see your future as well past.

Answer 14

It is impossible to travel at the speed of light. Say you were traveling close to it ( like 0.9999c ) : everything would still appear normal to you. That is, the light would shine from the headlights as fast as normal (in your perspective).

Answer 15

you cant be DRIVING AT THE SPEED OF LIGHT..



BUT IF YOU WERE DRIVING at just under the speed of light .. and turned on your headlights you would perceive the headlights as travelling at the speed of light..



because of length contraction.. the distance light has to travel the faster the light producing object .. goes shrinks .. and is UNDEFINED AT THE SPEED OF LIGHT that is why the question as you asked is bogus..



but at just under the speed of light the equation for contraction is still defined and the distance light travels would be HUGELY smaller than the distance it travels in our relative speed but we going at that speed would still measure the distance as the distance travelled by light..



the time would also change one second would be a huge time compared to our one second and thus the speed of light would be preserved..



you cant just use the relativity equations outside of where they are valid they are NOT VALID at speed of light..

Answer 16

You'd die

Answer 17

My engine blew up before Mach one.

Answer 18

The police will see you and give you a ticket and there will be a HUGE fine.

Answer 19

you won't see the light

Answer 20

You will become the light.

Answer 21

When you are driving at the speed of light , then you are no more in this world.

Answer 22

https://youtu.be/ACUuFg9Y9dY

Answer 23

Same thing if you are traveling at speed of sound and blow your horn.

Answer 24

Since it would be impossible for anything to be driven at the speed of light the question is moot.

Answer 25

I would like just one person who thinks time stops either relatively or absolutely at the speed of light to support their answer with actual physics.



The Lorentz time dilation is undefined at v=c so we do not have a valid relative time dilation equation. Additionally, light cannot be considered an inertial frame because it cannot ever be considered a rest frame, not can it be considered non-inertial since light cannot change velocity.



Proper time, the clock time of a clock carried by an observer, is only considered to be 'time' for v= c, it is considered proper length, not time.

Answer 26

If you have been accelerated to c then time dilation ensures you have zero time in which to switch the lights on.

Answer 27

I can never reach the headlight switch because time has stopped passing for me. If the lights were already on, no current would flow so no light would be developed in the headlights

Answer 28

It is about a fictitious experiment.





But in agreement with relativity, speed of light in the vacuum is a universal constant, which does not depend on the speed of the reference frame.

The emitted light will thus move away at the speed c of the transmitting source.







https://en.wikipedia.org/wiki/Velocity-addition_formula#Special_relativity

https://fr.wikipedia.org/wiki/Petites_exp%C3%A9riences_de_pens%C3%A9e

Answer 29

Forgetting the impossibility of it, as I assume you aren't interested in that. It would be similar to breaking the sound barrier, but with light. Your vehicle would be moving at the same speed as the light trying to move away from it. This light would build up in the head lamps, but never move out of them, and therefore would not light your way for you.

Answer 30

Hi Sullivan,



You could look back and see where you have been.



Poseidon

Answer 31

The light beams would compress to fit the speed of light, the light from your headlights wouldn't even leave the bulbs

Answer 32

As you get closer and closer to the speed of light time starts to slow down, theoretically if you could accelerate yourself to that speed then time relative to you would stop. So the problem is that you are basically frozen at the speed of light and you would be trapped in this weird time paradox that would take an infinite amount of time (from an outside perspective) to get out of... In short, you would just see whatever you were seeing the moment before you went that fast, just a regular car with headlights working how they normally do.

Answer 33

If you ignore the fact that at the speed of light, you stop, frozen and no time passes for you while you are moving that fast, the speed of light is constant and others would see you ~keeping up with light. Form your point of view light leaves you at the normal speed, but that is because the years that it takes for light to get a head are no time at all for you.

Answer 34

Your dick would explode

Answer 35

Okay, at the speed of light I'm not sure what would happen, maybe you'd infinitely increase in mass, or your time to another observer would completely stop... point is, these relativistic laws probably break down...



For the sake of this question, we will say close to the speed of light:



You will not notice anything strange happening in your own frame (everything that's going an insignificant speed relative to you, like your magical car, your trousers and shirt etc). Your headlights will work fine. However, you will notice that your surroundings that are whizzing past you at that speed will appear shorter in the same dimension as you are travelling. So if you travel north at something like 0.90*C, objects will have decreased in length in north direction by a factor of 0.43, so they appear 56% shorter.



What if someone else outside sees you? They'd see your car shorter by the same factor in the direction of travel the same way you see them, but everyone appears normal to themselves.



This does not happen with light, if someone outside your vehicle shines a torch in north direction, you wouldn't see that light trying to catch up with you, they'd see it at C (light speed). If they witnessed you put on your headlights, they would also measure the light speed to be C. This holds as one of the foundations of relativity, that the speed of light is the same to every observer in different reference frames.



Look up time dilation too.

Answer 36

How can you see if your moving that fast too? Eyes don't catch light moving when the lights go on. What the deal?

Answer 37

I say the speed of light in a true vacuum is constant

Answer 38

This is a very interesting question. Try it and find out, then tell us because we don't know for sure.

Answer 39

This is the old chestnut. It works like this. The light comes out of the lamp at the speed of light (SOL) and travels out at this speed PLUS the speed of the car, so that's SOL+SOL, twice the speed of light, OK so far?

Now the light hits the objective and is reflected back at the same speed that it hit the objective, so now the light returning to you is travelling at 4 time SOL, PLUS the speed of the car, so that makes the speed of the light received by you in the car 5 times the speed of light. You would not see anything as our eyes cannot detect this part of the electromagnetic spectrum.

Answer 40

You'll se the road you are driving on.... :-D

Answer 41

If you are at the speed of light then you have been reduced to a 2 dimensional being. Any light travelling at an angle to your plane of existence will disappear from your observation

Answer 42

The car would stop abruptly to prevent it's headlight beams from moving forward at twice the speed of light.



Hope this helps.

Answer 43

lol

Answer 44

You are driving at the speed of light (in your inertial frame of reference). However, fundamental principle is that you cannot reach light speed, because C is always 300,000km/s faster than you are. So, the light comes out of your headlights at 300,000km/s. Due to relativity, time dilation etc. etc. etc. anyone outside your frame of reference will measure the lights from you headlights at 300,000km/s regardless of what speed you are doing.

Answer 45

Jesus pulls you over and gives you a pony.

Answer 46

The scenario you are describing violates the Theory of Relativity and is impossible.

Answer 47

You become invisible.

Answer 48

your headlights would be on

Answer 49

AT the speed of light all time shrinks to zero.

So if you were viewed by an observer on any planet or star in the universe then all time has elapsed before you could reach the light switch.

Basically you are already dead and disintegrated, ceased to exist, are defunct, not alive.

So the whole question is moot.



If you are moving at ALMOST the speed of light relative to the earth then the light from your headlights still moves forwards at the speed of light.

But what is the point. Without any dust in space the light would move in straight lines. There is nothing to reflect from so it hardly matters. The headlights would show nothing back to you.



Why then did you try to turn them on?

What did you expect to see?

Answer 50

You wouldn't be able to do that because time doesn't pass at the speed of light.

Answer 51

If you are traveling at the speed of light then according to the theory of relativity you are stationary and the universe is moving infinity fast past you. Due to this theory, assuming it is true, if you turn your headlights on while traveling at the speed of light, you are technically stationary, and the light would emit forward in front of you at the speed of light.



However to an observer, you are traveling at the speed of light. If headlights are turned on, then the light wouldn't emit past the machine you're traveling in, as you'd be traveling the same speed as it. In addition, you'd appear to be infinitily flat, so you'd just look like a line with turned headlights traveling in a direction but the light from the headlights never emitting past your ship.

Answer 52

We apparently solved the speed of light equation. So henceforth someone invented the faster then the speed of light headlights. The new question is; who got the patents?

Answer 53

This is such a great question because, it throws all Netwonian mechanics out the window... This is the stuff that Einstein was talking about. All of Newton's 3 laws mean nothing in a case like this because Einstein understood inertial reference frames and the difference in cases regarding anything near the speed of light. I have no idea what would happen!

Answer 54

You get a ticket for speeding.

Answer 55

Nothing. literally No man made object has ever been able to travel faster than light or even AT the speed of light. Not even information.

Answer 56

Nothing

Answer 57

nothing (literally)

Answer 58

Although it is impossible to travel at the speed of light and this problem is purely theoretical I will grace it with a response. the light particles will travel relative to the headlights which would make the light be traveling at the speed of light squared. Now if you're wondering how this is possible, it happens all day everyday. When you drive at 30mph and turn on your headlights the light which is traveling relative to the headlight travels 30 times the speed of light .

I hope I have enlightened you.

Answer 59

I don't know... i'm gunna try it!!

Answer 60

Since it requires an infinite amount of energy to reach the speed of light, you will have used up all the energy in the universe, so your battery (which normally stores energy) will be flat. That means the lights won't work. Simple.