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.

  • XeroxCool@lemmy.world
    6·
    3 days ago

    Atoms are surprisingly bad at removing heat. Being hit with slower atoms and transferring that energy ((like newton’s cradle with mismatched swings opposing each other) transfers energy much, much faster than what happens naturally in the vacuum of space. Most spacecraft have more of issue with overheating than freezing. The rate at which radiation is emitted is very low when you get to sub-human temperatures. There’s also tons of heat sources around us in space, so the last few degrees are so, so hard to shed.

    Keeping a fridge stocked increases the thermal capacity of the coldness. Air falls out quickly and is subject to rapid temperature change when the door is open. Keeping a bunch of solid/sealed masses in there will bank the lack of heat. You’ll likely lose more air and the falling not-so-cool air will impart heat into your 24 pack of beer, but you’ll have a bunch of distirbuted cold objects to re-cool the air once the door is closed instead of relying on air circulation alone. Instead of raising the air temp by, say, 5 degrees once settled, it’ll only go up maybe 2 degrees - much better for food storage. But the fridge will still have to re-cool those beers, too.

    • Artisian@lemmy.worldEnglish
      4·
      3 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·
        3 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.