Ok this is a physical one.

Temperature is just the total speed of molecule vibrations in an object.

Vibrations are movement. Movement needs energy. All things thrive to be in an energy neutral state, energy always disperses, disbalances are always balanced out.

This means that the natural state of objects is 0°K, the lowest temperature possible, no movement.

That is why you should fill up your fridge and freezer! The only energy you need is for removing heat that comes into the thing and would in turn transfer to cooler objects and warm them up.

But keeping things cool itself doesnt need any energy 🤯

And if you heat it up then less air comes in, and the incoming air will be cooled down faster (energy balanced out between low density air and high density things). So the overall temperature doesnt spike as much and less needs to be transported off.

  • Artisian@lemmy.worldEnglish
    4·
    2 days ago

    “Spacecraft have more of an issue with overheating than freezing” is a really really coolhot fact. Do you have an easy source, maybe somewhere that discusses techniques/history?

    • XeroxCool@lemmy.world
      3·
      2 days ago

      I’d have to look for specific discussions, but I have some examples. The wiki page covers a lot. Spacewalk/moonwalk suits are white to reflect the sun’s heat (the orange suits are for takeoff/landing, a sin, terrestrial recovery). That shiny silver or gold foul appearance of classic space craft from the 60s/70s is for heat reflection. The JWST is on like 4 layers of wafers (they look like a sail) to isolate it from the sun’s heat. Quite visibly in depictions, the scrunched panels on the ISS are actually radiators.

      There’s a misconception about space and heat. It didn’t originate, but I’m Sur eit was propogated by the 00s space movie that had an astronaut pop off their helmet and freeze. Mission to Mars? Red Planet? Space cowboys? Yes, you probably would freeze upon exposure to space, but not because it’s cold. The sudden drop in pressure would vaporized a tremendous amount of water from you. Jus like how sweat works, the evaporative cooling would drop your skin temperature greatly.

      A side topic is that there’s narrow frequency range of radiation that is neither emitted by the sun nor reflected by the atmosphere. It’s in the near if rated range. There’s a NighthawkInLight video that develops a paint that resonates in this “window” to actually cool it below ambient air temperature. There’s always a control piece for science’s sake.