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I was wondering about this idea. That if we lets say have a metal cube in a vacuum sealed container and use a magnetic field to keep the metal cube afloat so that it doesnt have contact with anything. Before any of that we heat the metal cube. What I know is that heat transfer due to molecules colliding in this case there is no contact. Does this mean that the thermal energy of the cube will never be lost therefore we can store thermal energy. Is this possible?


marked as duplicate by sammy gerbil, Gert, lemon, Jon Custer, stafusa Nov 10 '17 at 20:33

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    $\begingroup$ Levitating the cube would prevent heat loss by conduction, and doing it in vacuum would prevent heat loss by convection, but the cube still will radiate heat. Polishing the sides of the cube and the walls of the vacuum chamber to a mirror finish would help to minimize the heat lost by radiation, but there is no practical way to completely eliminate the radiation. $\endgroup$ – Solomon Slow Nov 10 '17 at 14:57
  • $\begingroup$ P.S., Suspend the cube from a fine thread. For all practical purposes, it'll work as well as levitating the cube, and it will be a whole lot less expensive. $\endgroup$ – Solomon Slow Nov 10 '17 at 14:58
  • $\begingroup$ P.P.S., see also: en.wikipedia.org/wiki/Vacuum_flask $\endgroup$ – Solomon Slow Nov 10 '17 at 15:00

Firstly, 'heat' is not the same thing as 'thermal energy'. But no, in reality you can't store thermal energy indefinitely because hot things radiate energy in the form of EM radiation.

  • $\begingroup$ Wouldn't a black hole be a correct place to store thermal energy indefinetely? $\endgroup$ – dan Nov 10 '17 at 15:26
  • $\begingroup$ @danielAzuelos For a start, black holes don't last forever. $\endgroup$ – lemon Nov 10 '17 at 16:18

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