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[–] 10 points 2 months ago* (4 children)

Air within the can rapidly cools and becomes a low pressure. The higher pressure atmosphere outside the can compresses it.

Earth's atmosphere is pretty heavy.

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  • [–] 1 point 2 months ago (3 children)

    But it's the vacuum of the high pressure air escaping that causes the can to decompress, not cooling air that we see as steam. The kitchen pressure was the same one affecting the can outside when it was being heated, it was the rapid change in temperature that caused the hot high pressure air inside the can to rush and vacuum pull the can: decompression.

    You can try it out if you want with a hot air ballon or bag. The ballon or bag will simply reform ot it's original deflated form.

    Vacuum is the decompressor here, not the air.

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  • [–] 4 points 2 months ago (2 children)

    Not to get overly pedantic, but I don't think decompression means what you think it means.

    Also, the same pressure is acting on a fluid with a high energy/lowered density. When its cooled, the air wants to have a higher density, thus reducing the pressure inside the can relative to the atmospheric pressure that it is experiencing. It begins to suck in more "cool" water, which continues lowering the temperature of the water present. This is both because it is "cooler" to begin with as well as the latent heat of vaporization and it most likely aerosolizing as it enters the can turbo charging the feedback loop

    If you've ever actually done this, you'll notice that there is a "small" amount of water inside the can, that is the rememnent of the steam as well as the water that got sucked into it.

    Its also worth trying to work out, thermodynamically, why would the hot steam want to rush out of the can??

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  • [–] 1 point 2 months ago* (1 child)

    Because the can thermodynamically changed quickly, not the airs, not the water.

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  • [–] 1 point 2 months ago

    How compressible is metal vs how compressible is steam, when they are cooled?

    I can tell you that while metal shrinkage is non-negligible, steam condensing is several factors more compressible.

    Or are you saying something else that I'm not following?

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