For a moment, assume that travel at/over the speed of light is possible, and we fire a laser in front of us, what happens to the light emitted from the laser?

Would the photons scatter, or would the light only move at light-speed (that is to say, without a visible source).

Edit: To add to this, I realise that the light would be doppler-shifted.


closed as off-topic by Kyle Kanos, jinawee, Ben Crowell, Kyle Oman, ACuriousMind Aug 6 '14 at 21:09

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "We deal with mainstream physics here. Questions about the general correctness of unpublished personal theories are off topic, although specific questions evaluating new theories in the context of established science are usually allowed. For more information, see Is non mainstream physics appropriate for this site?." – Kyle Kanos, jinawee, Ben Crowell, Kyle Oman, ACuriousMind
If this question can be reworded to fit the rules in the help center, please edit the question.

  • $\begingroup$ From the Help Center: Questions about physics of fictional worlds which are not sufficiently grounded in real physics are off topic here. This question is asking about a situation that is verboten with real physics. $\endgroup$ – Kyle Kanos Aug 6 '14 at 20:59
  • $\begingroup$ An edit : assume that at or near speed of light travel is possible. If this question seems wrong then Einstein shouldn't have asked it too. $\endgroup$ – Andres Salas Aug 6 '14 at 21:29
  • 1
    $\begingroup$ @AndresSalas, you've materially changed the question with your edit and, further, this edit makes the only answer given inappropriate. I consider this bad form and so I'm rolling back your edit. $\endgroup$ – Alfred Centauri Aug 6 '14 at 21:55
  • $\begingroup$ It is possible to move faster than the speed of light in a medium, so I'm not sure it's appropriate to flag this question as non-mainstream physics. In that case, as always, the speed of the light is independent of the speed of the source. $\endgroup$ – benrg Aug 6 '14 at 23:16
  • $\begingroup$ @benrg: non-mainstream covers fictional physics. Surely photons can exceed $c_m$ for media $m$, but it does not mean that spaceships/people can exceed $c$. $\endgroup$ – Kyle Kanos Aug 6 '14 at 23:28

For the observer traveling faster than the speed of light the light of the laser must appear to move away from him at the speed of light.

For the observer in the rest frame, the laser light travels slower than the person firing it.

I conclude that time is moving backwards for the guy with the laser...

But seriously - we are breaking laws of physics here. I think it should be anyone's guess what happens when you do that...


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