Gas Laser Travelling at Near c?

It's not only the length, but the tube's diameter that affects the gain. Because the atoms in the tube lose their energy to the walls of the cavity causing them to go back to the ground state. And the length contraction only takes place along the direction of motion.

It doesn't mean that the ~one meter long gain-length of the laser shortens. Because the laser does not contract in its own frame, it only looks shorter when measured by someone in a frame of reference moving with respect to the laser.

The effect you get if it is coming extremely fast towards you for example, is that the light would be blue shifted to gamma radiation.

Roam said:

It doesn't mean that the ~one meter long gain-length of the laser shortens. Because the laser does not contract in its own frame, it only looks shorter when measured by someone in a frame of reference moving with respect to the laser.

The effect you get if it is coming extremely fast towards you for example, is that the light would be blue shifted to gamma radiation.

Click to expand...

This is interesting to remember, because we figure an outside observer would see some strangeness, but to the laser's frame of reference, everything is operating as normal!

It's already happening in your lasers right now, only you can't see it because you're in the same frame of reference.

That was the trippiest thing ever. You know you always hear people say there is no way to travel faster than light, and that is obviously false because as always, it depends on your frame of reference. I think instead, it was meant to be worded that an object in a static frame of reference cannot be accelerated past the speed of light.