Like fossil fuels come from organic matter that grew because of the sun. Is there any form of energy on that cannot be traced back to the sun in some way?

  • CanadaPlus@lemmy.sdf.org
    link
    fedilink
    English
    arrow-up
    48
    ·
    edit-2
    2 months ago

    Geothermal, which at this point in geological history mostly comes from decaying radioactive elements. It’s of minor industrial importance, but it fuels undersea vent ecosystems, and does see some use in traditional cultures.

    Speaking of radioactive elements, our nuclear generators all run on energy trapped from ancient cosmic catastrophes. Probably colliding neutron stars, for the most part. Hydrogen fusion has been made to happen for research and in atomic bombs - although interestingly we can’t use the same kind as the sun does.

    Tidal energy is used for some power generation, and it comes from the kinetic energy left in the Moon, and to a lesser degree the Earth itself, from the formation of the solar system.

    • Corkyskog@sh.itjust.works
      link
      fedilink
      English
      arrow-up
      1
      ·
      2 months ago

      kinetic energy left in the moon

      Does that mean that one day the moon will stop revolving and we will be tidal locked? If so, does that theoretically happen before the sun consumes us?

      • CanadaPlus@lemmy.sdf.org
        link
        fedilink
        English
        arrow-up
        3
        ·
        edit-2
        2 months ago

        It gets both slower and further away (to stay in orbit) every year, by like 2 cm IIRC.

        If you could go back a couple billion years it would be huge in the sky. There was even a period, called the Jatulian, where you might not have asphyxiated in the early atmosphere. There wouldn’t be much else to look at, though, and just your skin germs would be futuristic enough to completely change the course of life on Earth, once they get into the environment.

          • CanadaPlus@lemmy.sdf.org
            link
            fedilink
            English
            arrow-up
            3
            ·
            edit-2
            2 months ago

            Uhh, I actually don’t know the answer to that. Orbital mechanics is hard; see me being bamboozled elsewhere in the thread. At some point I’m guessing tidal forces from the sun would start having a major impact, since in reality they’re both in it’s gravitational well at the same time as they orbit each other. Usually that doesn’t make orbits more stable.

            Also, the sun will go red giant in 4 or 5 billion years, and will eat Venus for sure. The Earth and Moon may well suffer the same fate, we’re kind of right on the projected edge.

    • Randomgal@lemmy.ca
      link
      fedilink
      English
      arrow-up
      1
      ·
      2 months ago

      Do you have any source for the radioactive decay part? I always thought the Earth was hot inside simply because it hasn’t finished cooking down from when it formed as a ball of molten stuff. Like a hot potato.

      • CanadaPlus@lemmy.sdf.org
        link
        fedilink
        English
        arrow-up
        1
        ·
        edit-2
        2 months ago

        Uh, I’ll find one, and edit. It confused the shit out of Victorian scientists, because they had a good guess how old the Earth is from biology, and had thermodynamics, but it was telling them volcanism shouldn’t still be happening.

        Edit:

        Wikipedia mentions it in the geothermal article, but the source is a textbook, and who has time and/or money for that? There’s also the article on the age of the Earth. Ah, here we go, in the article on Earth’s internal heat budget. Somebody also linked a paper on it elsewhere in this thread.

        These give slightly different numbers from each other, but the gist is that radioisotopes (Uranium, Thorium and Potassium being the primordial ones) account for at least half.

        • Randomgal@lemmy.ca
          link
          fedilink
          English
          arrow-up
          1
          ·
          2 months ago

          Oh interesting. It turns out it’s more like a demonically possesed hot potato, that is still cooling down but also gets warmer from demonic activity under the earth.

          • CanadaPlus@lemmy.sdf.org
            link
            fedilink
            English
            arrow-up
            2
            ·
            edit-2
            2 months ago

            More like a hot banana, going by the potassium.

            I actually had no idea radioactive potassium was primordial until I read this. That’s neat.