If a car travels at the speed of light and turns headlights on what happens?

Apopcalyptic said:
Physics isn't really my thing, but because of the laws of perpetual motion, would the light not be projected at twice the speed of light?
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no, speed of light is a universal constant

i think, i havent done this for ages.
 
IIRC, relative to the car the light will travel away from the car at the speed of light just as it would if the car was going stationary. But, that means relative to a stationary bystander, the light being projected from the headlights is travelling at 2c, which is theoretically impossible...or is it?

My head is fried.
 
ahhhh proper bend your mind question.

Right, from my wacky interests in question like this, this is my understanding so far.

The speed of light is not constant. Light is an Elcromagnetic wave and like all waves, it depends on what its traveling through, but i assume you mean the speed of light in a vacum, like in space.

Now with a bit of weird Einstein theory, we can say that Time is not constant. Its merely observed from us people going round at stupidly slow speeds comparried to the speed of light in space.

So with Time not being constant, and if you are going round at the speed of light, you would not be able to observe any changes, so in effect time would appear to stop. (The phrase of time slowing down normally reffered to as Time Dialation). The faster an object moves, the slower time passes for the object.

This effect can be messured as the GPS salelites knocking round the Earth have a yearly time correction of 1/1000000 of a second (or there abouts).

If you were at the speed of light with your lights on, then from the stationary observer, the Mass of the Vessel and light would appear at the same time, from the passengers perspective, nothing would be happening atall as time would have appeared to stop, but with no time passing then they would not know.

If you were traveling a a fraction under the speed of light, and you turned your lights on, then from your perspective on the vessel at speed, it would appear that the light was beamed ahead normally, how would you know that time is slowing for you?

From the observer stationary there would be a difference between the light and the mass. but as the mass is not traveling at the speed of light, it doen't really answer your question.
 
no to that observer wouldn't the distance/time be different, so it owuld also be c??

again vague memorys of a distant past :0
 
c is the speed of light
a car at 0.9c relative to a stationary observer

from the perspective of the car
the light emitted by the headlights moves away from the car at c



If the car is moving directly away from the observer;

according to the lorentz velocity transfomation
http://hyperphysics.phy-astr.gsu.edu/Hbase/relativ/veltran.html
relv4.gif

sub in:
u=(c+0.9c)/(1+(0.9c*1c/(c*c)))
u=1.9c/(1+(0.9c*c/(c*c)))
u=1.9c/(1+0.9)
u=c

Hence, and more generally, the light from the headlights is measured as travelling at c in ANY inertial frame (a frame of referance that is not accelerating.)

everyone sees all light travelling at the speed of light.
 
callmeBadger said:
The speed of light is not constant. Light is an Elcromagnetic wave and like all waves
Click to expand...

Can't be bothrered with a proper response, but the duality of light states that in some cases light behaves as a wave, and in other cases it behaves as particles. Or am I thinking of sommit else, it's been years since I last did physics.... :confused:

Oh, and off topic, where has my quick post gone, my laziness enjoyed having that thing!
 
The real question is, while travelling at the speed of light and eating your packed lunch, does the pair of half slices of bread with filling constitute one or two sandwiches?
 
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