• qjkxbmwvz@startrek.website
    link
    fedilink
    arrow-up
    11
    ·
    7 months ago

    I’m too lazy to work through the numbers but I think helium production would be very small — which is another way of saying fusion (as envisioned for energy use) produces a huge amount of energy.

    • grue@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      ·
      7 months ago

      fusion produces a huge amount of energy.

      That’s the kind of claim that’ll age like “640k ought to be enough for anyone.”

      • qjkxbmwvz@startrek.website
        link
        fedilink
        arrow-up
        1
        ·
        edit-2
        7 months ago

        Googling around, you get about 1e11 kJ/gram of He produced (source.

        Wikipedia says Hindenburg volume is 200,000 m cubed . Multiply by density of He at stp and you get north of 1e7 grams.

        Multiply and you get 1e21 J. Estimate for worldwide energy consumption in 2010, from Wolfram Alpha, is half of that.

        So, if all energy were from local fusion, it would take about two years of production to fill a single Hindenburg-sized Zeppelin. That is a huge amount of energy.

        I don’t think it’s equivalent to compare energy with RAM like this. Energy is the realm of thermodynamics; things like boiling water don’t care about technology, they just need a certain amount of energy. Unless we’re talking about fundamentally new uses of energy, like floating cities or something whacky, I think the amount of energy here is really, really big.