• Hello_there
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    522 months ago

    Send this to xkcd and we’ll know how many tons of uranium are required to get it done

    • @[email protected]
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      2 months ago

      Randall Munroe might be busy, so I’ll try.

      Okay, according to cooking StackOverflow, a popcorn kernel pops at about 180-200C. Once Iowa is dry enough for the corn to pop, that’s the target temperature, and according to the USDA Iowa produced 2.58 billion bushels of corn in 2024. It appears in Iowa it’s still cold enough they have just one harvest, and we’ll assume by timing our microwave burst right we can get 2 billion. If we approximate the kernel as all water, we can consult the steam tables for energy absorbed heating water at STP to 190C at 10 bars, and with the fact a bushel of corn weighs ~25kg get (2602.8-83.83)kJ/kg * 2 * 10^9 bushels * 25kg/bushel = 125.9 PJ. Reactor-grade uranium has an energy density 3.456TJ/kg in practice, per Wikipedia. So, the unrealistic answer is 125.9PJ/(3.456TJ/kg) ~= 36.5 metric tons, which you could actually fit in a cargo aircraft.

      I’m going to come back and add in more realistic answers including the (alleged) non-corn things in Iowa, and then including the need to store that energy in a way that can be quickly turned into microwaves.

      • Hello_there
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        42 months ago

        You also need enough heavy water to go between the u rods right? Seems like a lot of additional volume and mass for that

        • @[email protected]
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          32 months ago

          Fine, I’ll include plant mass with the (almost certainly much larger) mass of all the ultracapacitors when I start on part 2.

          • Hello_there
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            42 months ago

            Hey, I’m already happy with your answer. Just saying it’s starting to look less like an aircraft and more like a building

      • @[email protected]
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        22 months ago

        There will also be some atmospheric loss, so increase the PJ a bit, depending on what altitude you deploy the satellite to.

        Also, it’ll need to recharge, Kansas is next.

        • @[email protected]
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          22 months ago

          I’ll leave waiting for a clear day and adding 10% as an exercise for the reader. It will definitely be rechargeable, just supply more uranium to the reactor and wait again.

        • Pirky
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          42 months ago

          Hmmm, a nuclear based propellant. Might be easiest to make it a pulse based rocket so you can use a bunch of tiny nuclear explosions to propel yourself into space. I’m sure that won’t have any environmental ramifications.

    • @[email protected]
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      12 months ago

      Can XKCD also figure out how big a space based solar panel has to be to cast a visible shadow?

  • Schiffsmädchenjunge
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    132 months ago

    I am all in favor of this, but I do have to ask if there is a specific reason behind this (apart from the obvious).

  • @[email protected]
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    42 months ago

    a tesla that goes up in flames is a tesla that won’t contribute revenue to Elon in the future.

    • @[email protected]
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      22 months ago

      Can you pop corn with a popped Tesla battery? Can we commander a fleet of Teslas and pop their batteries remotely?

      Maybe you’re on to something and we can get away with a smaller satellite.

      I’m not sure what Elon has to do with anything tho.