Speed of light
| Guppy |
Sunday, December 19, 2010 at 3:32 PM |
(hypothetically) If a car is driving at the speed of light and it turns on its headlights will they shine?
| Guest |
Thursday, January 6, 2011 at 8:29 AM |
Yes. If you're travelling at the speed of light when you shine your headlights, you headlights will travel at the speed of light relative to your original speed. But always remember you can only travel at the speed of light. Not double.
| Guest |
Wednesday, February 2, 2011 at 7:01 PM |
so a body in rest observing the headlights would see them how? traveling at the speed of light or faster?
| Curtis |
Wednesday, February 2, 2011 at 7:33 PM |
The observer always sees the light from the headlights as traveling at the speed of light. Doesn't matter if the observer is at "rest", or moving towards the lights, or away from the lights, or at what speed.
That's what makes the whole thing so weird. This was Einstein's big breakthrough - the realization that if the speed the light travels doesn't change, everything else (i.e. time and space) must change instead, in order for the math to add up.
And we're talking about the really simple math here, as in [ speed = distance / time ]. If the speed doesn't change, that means the distance or the time (or both) must change instead.
Simple. Brilliant. Absolutely counter-intuitive. And with truly mind-boggling consequences.
| Guest |
Wednesday, February 2, 2011 at 8:04 PM |
that is amazing. thanks for responding so quickly Curtis
| Guest |
Monday, February 14, 2011 at 12:05 AM |
I'm sorry but this is false. if you are riding a bike and throw a ball forward the ball will have the velocity that you give it plus the velocity that you started with on the bike because it stated out in motion. HOWEVER, it you are riding a bike and turn on a flashlight facing forward, the light still travels at the speed of light no faster. not even light can go faster than light.
lets say you are traveling in a space ship and are going at the speed of light. if you were again to tun on the flashlight and look you would see light STANDING STILL. how cool is that if you don't believe me then look up Einstein's Light Beam thought experiment.
| Guest |
Tuesday, February 22, 2011 at 9:23 AM |
If you were to be traveling at the speed of light, you would have zero "thickness", infinite mass, and time would stop
i could be missing the point entirely here, but this sounds very much like a black hole? zero "thickness" with infinite mass?
awesome physics
| Curtis |
Tuesday, February 22, 2011 at 4:04 PM |
Umm.. yeah. hadn't really thought about that, but it is kind of similar. A few key differences: Black holes have occupy zero distance in all dimensions, whereas our imaginary traveler still has a measurable height and width. Also, black holes do have a finite mass. Because they are compressed into a single point, they have an infinite density. (But as any mathematician will tell you, all "infinities" are not created equal.)
| Guest |
Tuesday, July 19, 2011 at 11:51 PM |
:/ difficult question, probably not even a physicist would be able to give you a finite answer as special relativity predicts the mass, length, energy, etc of object going at relativistic speeds but never reaching c... special relativity does not predict with certainty what happens when c is reached as it is considered impossible :/
| Curtis |
Wednesday, July 20, 2011 at 1:45 PM |
very true, and good point. c is an asymptotic limit, that can never really be reached, and the values for mass, dimension, etc are strictly speaking undefined at that limit. we make assumptions of what they could be based on the mathematical functions that describe thier behavior short of the limit.
Simple example: if y = 1 / x, the value of y is undefined when x = 0, however the limit of y, as x approaches zero, is infinity.
| Guest |
Sunday, December 21, 2014 at 12:14 PM |
The question did not ask the limit so the answer is simply undefined or infinity - take your pick.
