I am driving my car at the speed of light and I turn on my headlights. What do I see?

[Iwikefactz]

I am driving my car at the speed of light and I turn on my headlights. What do I see?

[Cap'n Refsmmat]

You can explore the situation in both reference frames (stationary observer and moving flashlight) here:

 

http://www.refsmmat.com/jsphys/relativity/relativity.html#flashlight

 

In short: you always see the light traveling away from you at the speed of light.

 

(Of course, you can't drive your car at the speed of light--only infinitely close to it.)

[J.C.MacSwell]

I am driving my car at the speed of light and I turn on my headlights. What do I see?

 

Have you driven a car and turned on your headlights? What did you see?

 

Relative to some inertial frames you were almost at lightspeed, but at light speed in none.

[MigL]

Hold on now...

 

The speed of light is measured to be c in any valid frame.

To be able to move at light-speed you and your car need to be massless.

There is no valid frame for any massless particle or object.

 

A conundrum !

(always wanted to use that word)

[Mayflow]

I am driving my car at the speed of light and I turn on my headlights. What do I see?

 

Probably light from the headlights and stuff it reflects from. Remember to look in the rear view mirror though. Drive safe.

[Schneibster]

I will only add that you can't drive your car at the speed of light; however, you can get very very very close, and when you do, you will see nothing abnormal when you turn on the headlights, except the road will seem a lot shorter!

[studiot]

 

(Of course, you can't drive your car at the speed of light--only infinitely close to it.)

 

 

With respect should that not be infinitesimally close, infinitely distant?

[Schneibster]

 

With respect should that not be infinitesimally close, infinitely distant?

 

Yes.

 

However in the Cap'n's defense, it's a mistake we all make. And it does take infinite energy, so "infinitely close to the speed of light" makes colloquial sense, if not precise pedantic fussy accuracy.

 

(Sorry, Cap'n, I assumed it was my mistake. I wasn't trying to be funny at your expense but at my own.)

Edited April 5, 2014 by Schneibster

[davidivad]

if you are almost treking along at the speed of light, you yourself would experience the roasting of a lifetime but the headlights would work.

a non-speedy observer would never get to see you roast.

 

at the impossible speed of light, you would not be able to ever get around to turning on the lights. however, if the lights were already on, i would imagine Cerenkov radiation might be observable to said non-speedy observer in some way or fashion.

of course this is just speculation.

 

come to think of it i would guess at this "sonic boom" in both scenarios.

Edited April 5, 2014 by davidivad

[michel123456]

Hold on now...

 

The speed of light is measured to be c in any valid frame.

To be able to move at light-speed you and your car need to be massless.

There is no valid frame for any massless particle or object.

 

A conundrum !

(always wanted to use that word)

Does that mean no mass or no mass? I mean, if he uses a speculative anti-gravity device, does that help?

[swansont]

Does that mean no mass or no mass? I mean, if he uses a speculative anti-gravity device, does that help?

Not in a discussion about physics.