Comment on Explosions in the Sky

• vithigar@lemmy.ca ⁨2⁩ ⁨weeks⁩ ago

  On the overall scale of the universe? No, not even remotely close. On the local scale of the Earth, generally yes.

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  • yetAnotherUser@discuss.tchncs.de ⁨2⁩ ⁨weeks⁩ ago

    Well, as much as possible anyway. When considering mass alone, life is quite efficient.

    According to Wolfram Alpha:

    The sun produces 3.8 * 10^28^ watts.

    A single human produces 104 watts (calculated through the average caloric intake assuming that intake ≈ energy consumption) through heat radiation.

    Therefore:

    1 kg of human converts 1.5 watt into heat.

    1 kg of the sun converts 0.0002 watt into (heat) radiation.

    And while I have nearly no understanding how entropy is calculated, from those values alone it seems like humans produce more entropy per kg than the sun. I’m pretty sure entropy is somewhat related to energy production though.

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    • vithigar@lemmy.ca ⁨2⁩ ⁨weeks⁩ ago

      Yes, if you consider just a human-mass equivalent portion of the Sun then it’s not doing much, but that’s not really a useful comparison. We’re talking about total net entropy here, not entropy per unit mass.

      But yes, if it makes you feel any better, I’ll concede that if you had octillions of people our total metabolic energy output would, in fact, be significantly higher than that of the Sun.

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      • Buddahriffic@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

        This raises the question of how many kg of human mass is required to start fusion and create a human star? How does fusion even work if you have a mix of different elements? Would the human star pulse in a cycle of collapsing until hydrogen fusion starts, exploding out until it stops and then collapsing again? Or would any fusion ignite enough to stop it from collapsing into a neutron star or black hole?

        And if I’ve asked this question, does it mean xkcd has already attempted an answer? Or at least a comic that mentions it?

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