I have had this idea, and I'm not sure if it would work. Heat is a form of chaotic kinetic energy, right?. Would it be possible to create a magnetic field within a gas or liquid so that when the medium vibrates the magnetic field would shift? Could we do this inside an insulated sphere of, say, aerogel and titanium, and then place super-light ferromagnetic particles in a shock-absorbing medium surrounding it so that the heat would be transferred out by magnets but blocked from coming back in? Would this gradually cool the internal medium without requiring any energy input? Could we generate energy from the exiting heat? It seems to check out with any physics I still understand (energy leaves, entropy decreases, etc.), but everyone I've asked said that if it worked, it would have been done already. Still, I can't get this out of my head. Thanks!

closed as unclear what you're asking by Norbert Schuch, user36790, John Rennie, Sebastian Riese, Gert Dec 10 '15 at 0:07

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  • This is absolutely impossible. Whenever you think you've thought of a way to passively move heat from one place to another so as to cool an object, it's incorrect. Usually this is because whatever process you've thought of to remove heat also acts in the inverse direction to move heat back in. This is absolutely fundamental. Here is a very detailed example. – DanielSank Dec 9 '15 at 8:23
  • Naturally the energy would be able to get back into the sphere, but I was wondering if you could get just some of the heat on the outside to dissipate as more structured waves so that the heat would gradually decrease. – John Smith Dec 9 '15 at 9:48
up vote 1 down vote accepted

The only way you can do this is with a magnetohydrodynamic generator, where an very hot ionized gas is passed very quickly through a magnetic field and thereby generating a voltage across the gas.

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