Comment on Falling

Granixo@feddit.cl ⁨2⁩ ⁨years⁩ ago

• shutz@lemmy.ca ⁨2⁩ ⁨years⁩ ago

  It’s not density, it’s mass. A mass of 1kg compressed to the density of the Sun’s core would pull the Earth with just as much force as a 1kg ball of styrofoam.

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  • rockerface@lemm.ee ⁨2⁩ ⁨years⁩ ago

    And is the Sun was replaced with a black hole of the same mass, the Earth would just keep on rotating around it without issues, if slightly frozen

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    • chatokun@lemmy.dbzer0.com ⁨2⁩ ⁨years⁩ ago

      Xkcd did a what if on a black hole moon (getting it to collapse into one may be impossible, but a black hole the mass of the moon is theoretically stable), and it has the same conclusion, except just slightly colder instead of slightly frozen. And by slightly, I mean almost imperceptible.

      what-if.xkcd.com/129/

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      • rockerface@lemm.ee ⁨2⁩ ⁨years⁩ ago

        I mean, the Sun also contributes slightly more heat to the Earth compared to the Moon. And by slightly, I mean the difference between cold and frozen

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  • Chrobin@discuss.tchncs.de ⁨2⁩ ⁨years⁩ ago

    Just to add some formality to it, the original commenter might want to look up the shell theorem for classical mechanics and Birkhoff’s theorem for general relativity.

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• Carrolade@lemmy.world ⁨2⁩ ⁨years⁩ ago

  The guy on the right, if he be so wise in the ways of science, should be using the word “mass” instead of “weight”.

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• hddsx@lemmy.ca ⁨2⁩ ⁨years⁩ ago

  Can you explain please

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  • KillerTofu@lemmy.world ⁨2⁩ ⁨years⁩ ago

    Heavy is a subjective term based on the force of gravity. You are heavier if we weigh you on the earth compared to if you are weighed on the moon.

    Your density in those to examples is unchanged. The amount of mass you have is finite and not subjective like weight.

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  • Granixo@feddit.cl ⁨2⁩ ⁨years⁩ ago

    The feather clearly has a more aerodynamic shape, thus, it wouldn’t fall as fast as a sphere with the same weight.

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    • discostjohn@programming.dev ⁨2⁩ ⁨years⁩ ago

      Lol, no

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