If I were to fire a laser while I'm traveling close to the speed of light, how fast would the laser travel?

Question

Assumptions: No physical obstructions. No gravitational interference.

Answer from 2 perspectives:

(1) My perspective as the traveler/firer
(2) An alternate perspective with the observational precision to view the event in "slow motion."

Assumptions; No physical obsructions/gravitational interference.

Answer 1

From your point of view it would travel at light speed.
For the innocent bystander,...well... who the hell asks them anyway?!
But there is the dillema: The laser would travel at lightspeed and you would stagger shortly behind it. Still the first laser-particle would fly away from you at lightspeed.
The difference from the bystander's to your perception is that your time is slowed.
Need an equation?
Well, let's try:
From the bystander the relative lightspeed with you travelling at c/2 would be another c/2 since

c/2 + c/2 = c

easy so far.

For you, lets assume that c/2 is now the actual c as you perceive it (lost myself her, lets move on blind:)

Now lets remember that your time is slowed. In the second that the laser travels this 299........km it actually travels double the distance. As you are slow the laser has two of your seconds as it is faster in your perception.

As c is a velocity lets assume c= 300.000 km / 1 sec.
then c/2 = 150.000 km / 1 sec.

But as stated earlier the laser has 2 sec. time to travel. This brings you to see the laser fly off at

c(laser seen by you) = 300.000 / 2 sec.

Here we go:
As you are at half speed you perceive 2 laser-seconds as one of your seconds. Then you are again at:

c = 300.000 km / sec!
QED - Hooray

The thing with the complicated formula mentioned above is that I think this complicated term will shorten itself out. Nevertheless, I hope you got the idea! Happy trying!

Answer 2

Finally somebody who asks a reasonable question (the one with the observer travelling at the speed of light is a fallacy of physical law). At any rate, to answer your question:

Relativity states that the speed of light is constant to all observers regardless of reference frame velocity (keeping in mind that all observers/reference frames must be travelling less than the speed of light, C). Okay, that's easy enough, the answer is that the laser would travel away from you at the speed of light... but the interesting part is WHY.

Well, velocity is equal to the distance divided by the time.

As you speed up, time actually expands. You would still measure time normally, but in the space that one second passes for you, three, four, ten, or any number of seconds might pass for an observer who is stationary. The closer you get to the speed of light, the longer one second takes. But that's only half the equation.

Well, it just so happens that the same thing that happens to time (expanding) also happens to distance in reverse. As you speed up, the length of a meter collapses. Since both time expand and distance collapse in (conveniently enough) a proportionate amount, the velocity for observed light equation remains constant for all observers, regardless of their speed.

Answer 3

The laser would travel at the speed of light.

This would be true from your perspective as well from a bystander's perspective. The speed of light is always constant. The time and distances from the two perspectives would be distorted.

Answer 4

Still speed of light. That is the definition.
Your perception of time would have been changed, however, compared to that of an outside observer.
It is weird, but that is why Einstein relativity theory took some work to be developped.

Answer 5

The speed of light is relative. So, however fast you are traveling, the laser will always appear to travel at the speed of light relative to you.

Answer 6

It would move away from you at the speed of light - from your point of view no different than if you were standing still. The speed of light, according to Relativity, is constant regardless of the frame of reference.

Answer 7

If you fired it forward you would see it go foward at the speed of light. If you fired it backward you would see it travel at the speed of light.

An observer that was not on your ship would see things differently. He would see the beam fired forward as traveling slowly. He would see the beam fired backwards traveling at the speed of light.

Answer 8

if you were to fire the Laser it would only be going away from you at the speed of light. from your viewpoint you would see the laser going away from you. from my viewpoint it would be you traveling and the laser in front of you.