In a hypothetical scenario, I'm trying to design an object where, the faster it moves, the more it cools something it comes into contact with it.

There's all kinds of materials that can convert energy into electricity or combine/dissociate compounds, but am I breaking any thermodynamical laws by posing such a device? Let's say for however many joules of kinetic energy it has, it uses 90% of those joules to do some kind of work, fuse sime kind of chemicals, move some kinds of magnets, in a way such those those are how many joules taken from an object in contact and radiated in some way shape or form in the opposite direction of contact. Is that physically possible?

  • $\begingroup$ How is this different from how a hydroelectric power plant uses the kinetic energy of water to spin the turbines to turn the generators to produce electric power which then gets used by your refrigerator to turn a motor to work the compressor to circulate the cooling fluid to cool the things you place inside? Yes, if you have a source of free energy (in the physical sense, not in the sense of costless) you can use that energy to work a heat pump to cool down stuff. $\endgroup$
    – AlexP
    May 7, 2022 at 23:36
  • $\begingroup$ @AlexP Or using a water wheel to directly turn the compressor on your AC? $\endgroup$
    – DKNguyen
    May 8, 2022 at 1:17
  • $\begingroup$ There is no such thing as 'heat'. There are only molecules vibrating faster or slower. The slower they vibrate, the less they are said to have 'heat'. The faster they vibrate, the more they are said to have 'heat'. Sometimes, this vibration causes the object to emit EM radiation, or light (visible or IR), or other radiant energy. Sometimes the vibrations are transferred to other objects (conduction). Then the object is considered to be losing 'heat' in the sense that the vibration energy is converted to other energy. But it is not 'heat' that is lost, it is that the vibrations are lessened. $\endgroup$ May 8, 2022 at 2:04

1 Answer 1


It is very possible.

You have invented wind.



The faster it moves against an object, the more the object is cooled. It is because more molecules of gas come in contact with the object, each carrying away some heat energy. It would be very easy and very plausible to use in a story.

  • $\begingroup$ Case solved, congratulations :) $\endgroup$ May 8, 2022 at 15:10
  • 1
    $\begingroup$ So in other words, the more cold molecules there are flowing per second, the greater the wind-chill effect. $\endgroup$
    – StackQuest
    May 8, 2022 at 19:29
  • $\begingroup$ I've got to upvote this one just because I'm from Minnesota. I will rudely point out that past a certain velocity, the effect breaks down and generates heat from friction (because someone has to post the irritating details in a hard science question). $\endgroup$
    – DWKraus
    May 8, 2022 at 23:28
  • $\begingroup$ Vortex tubes probably deserve a mention, here. $\endgroup$
    – Matthew
    May 9, 2022 at 20:22
  • $\begingroup$ @DWKraus - I wonder if a February free fall in Faribault would be enough to get warm or if the wind would need to be faster than terminal velocity? $\endgroup$
    – Willk
    May 10, 2022 at 15:26

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