• @[email protected]
    link
    fedilink
    English
    368 months ago

    Meme is referring to nuclear reactors, not complete antimatter annihilation.

    Nuclear reactors don’t “burn” everything — most of the matter stays (this is what nuclear waste is). So you can only apply E=mc^2 to the difference in mass, not the mass of the fuel.

    • @[email protected]
      link
      fedilink
      English
      15
      edit-2
      8 months ago

      You know it’s funny, technically a calorie is just a measure of how much energy it takes to heat up 1 gram of water 1° C I never really thought about it but it could totally be applied to other things and nuclear reactor plants that literally just heat up water to spin a turbine would be the perfect thing to measure in calories. So would regular electric plants for that matter. It might just be literally calories.

      Oh shoot that would be some wild math to figure out how hungry they all are.

      • @[email protected]
        link
        fedilink
        English
        78 months ago

        Except that 1 gram of water is at 1 bar. Heating up 1 gram of water from 300°C to 301°C takes 1.38 calories.

    • @[email protected]
      link
      fedilink
      English
      58 months ago

      Can they really get out THAT many calories from a gram of Uranium?! That’s insane!

      I wish I cared more and would verify it

      • @[email protected]
        link
        fedilink
        English
        98 months ago

        Calories are just a measure of the energy released by a material.

        Normally they’re measured by burning the material, so it’s not really accurate to say that you can get that many calories from uranium. On the other hand the whole concept is fucking stupid anyway, because it’s measured by burning the material. Technically, a kilo of dry sawdust has 4800 calories (more than double the daily calorie requirement of the average person).

      • @[email protected]
        link
        fedilink
        English
        38 months ago

        I just googled around and I think the meme inflated the numbers. Fast neutron reactor gets 28GJ/g, which is “only” about 7 million food (kilo) calories.

    • @[email protected]
      link
      fedilink
      English
      4
      edit-2
      8 months ago

      The numbers don’t add up. If you can get 21 billion US food calories from total annihilation (which I checked is right), you’d get nowhere near 18 billion food calories from a fusion reaction. Maybe it works if you assume “calories” for the fission reaction means metric calories, since US food calories are metric kilocalories.

      I hate the way the word “calorie” ended up with two wildly different definitions.

      • @[email protected]
        link
        fedilink
        English
        58 months ago

        Yeah, I looked up energy density assuming fast neutron reactor, and it’s “only” 7 million US food calories.

        • @[email protected]
          link
          fedilink
          English
          38 months ago

          US calories are equal to the real metric unit of kilocalories. Maybe the meme above used real calories