Quote:
Originally Posted by wade_b
That is interesting but expected behavior on the particle level.
|
I think so too.
Quote:
Originally Posted by wade_b
The real question: is that recoil measurable in the laser itself, and does it follow the rules of Newtonian physics?
|
Not sure exactly what you mean by Newtonian physics, but lasers surely follow conservation of momentum. They follow Newton's first law - the law of inertia. They do recoil.
Quote:
Originally Posted by wade_b
I'm searching really for a good abstraction for the relativistic notion of an "open system" as applied to the emission device in the tuned cavity.
|
Once again, I'm a bit confused by what you mean. When you say "open system" do you mean a "relativity drive" that looses photons into open space? If so, that is a perfectly normal thing to consider as a rocket engine. Qfwfq touched on that earlier in post #10. A well-focused laser could essentially work as a rocket engine. The laser does have recoil equal to the momentum of the photons leaving the craft.
Quote:
Originally Posted by wade_b
This really does seem impossible, even when applying the Einstein Elevator and changing the reference frame.
|
That surely seems to be the consensus of the thread.
Quote:
Originally Posted by wade_b
If I understand correctly, the law of conservation of momentum still applies inside the elevator.
|
I think it's a safe bet that conservation laws always apply.
Quote:
Originally Posted by wade_b
The model I studied shows a force vector being applied from outside the elevator; the perception of momentum inside the elevator would be 0.
So I'm not quite seeing how a force generated inside the elevator could translate into momentum measured outside of it?  |
I don't see how it would work either. As Will said, there's nothing you can do inside the elevator to move its center of mass. So, it's not going to accelerate. Unless some mass leaves the craft or some force acts on the craft - it's not going to accelerate.
~modest
