Recent content by pcysics

So, given a large enough internal supply of energy, a refrigeration laser is possible, but not self-renewing, as the supply will eventually be depleted. I still don't understand how to actually build one, even in theory. You have all the power you want? From the sun, right? You can't extract...

That looks right.

Sorry, it seems I have yet to develop an intuitive grasp of the second law of thermodynamics. I'm not sure what you mean by steady-state. You've heard of electric "space heaters". They're compact and portable. They generate heat through electric resistance like a toaster, but this takes power...

Right, but the cold reservoir in this case would be the room itself, which the concentrator pump is extracting the heat from in the first place. This machine is supposed to be an air conditioner. Read my post #7 again.

Nope, not a laser. I said,

I wasn't referring to a term from the book, but to my first post: "to concentrate the heat inside the ship with some kind of heat pump". A heat pump is the same thing as some kind of refrigerator. The exact method used to pump the heat is probably irrelevant to our discussion. A refrigerator has...

I don't mean an electric light bulb. I mean heating something to incandescence using the concentrator pump. That's the same as "if parts of the ship are emitting blackbody radiation", right? Is it self-renewing now? Can it produce useful work? Could you dump the heat in some other way than the...

So the problem here is the way we output the heat energy? If instead of using a laser, we just used a focused incandescent light source with a higher temperature than the sun, the output would have higher entropy, right? Then could the system be self-renewing? If the temperature difference were...

I am NOT referring to laser cooling, the technique for supercooling atoms. The 1980 science fiction novel Sundiver by David Brin describes a kind of spaceship that could fly into the sun. One way described to keep the inside of the ship cool was to concentrate the heat inside the ship...