• Blue_Morpho@lemmy.world
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    4 days ago

    Uranium generates that energy by fission. The hydrogen in sugar could generate huge amounts of energy if fused.

    • TheTechnician27@lemmy.world
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      4 days ago

      And this boulder could generate huge amounts of energy if I pushed it up to the top of Mt. Kilimanjaro and let it roll down.

      44 upvotes and 0 downvotes for a comment that doesn’t understand that energy density measurements like this tend to measure the useful energy of a system.

    • nialv7@lemmy.world
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      4 days ago

      It’s disappointing that natural selection didn’t figure out fusion.

      • WhiskyTangoFoxtrot@lemmy.world
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        4 days ago

        It figured out photosynthesis instead. Why do your own fusion when you can just take advantage of the fusion that’s already happening?

      • SkyeStarfall@lemmy.blahaj.zone
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        3 days ago

        It’s good it didn’t, otherwise it’s possible that all the hydrogen in the ocean would be fused into helium by now

        Well, more likely it would significantly heat up earth due to the amount of energy released first, cooking everything/starting an endless cooking->extinction->cooling cycle

      • Trollception@sh.itjust.works
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        4 days ago

        We have fusion (hydrogen) bombs. We just haven’t figured out how to maintain and efficiently harness it for energy.

      • Blue_Morpho@lemmy.world
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        4 days ago

        Using the rule of thumb, anything heavier than iron requires energy input to fuse. So you lose energy fusing uranium.

      • davidgro@lemmy.world
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        4 days ago

        Serious answer: A huge negative amount. Anything above iron requires energy to fuse (which is why it produces energy from fission.) and I’m pretty sure nothing with 184 protons could be stable enough to count as being produced - the nuclei would be more smashed apart than merging at that point.

      • PunnyName@lemmy.world
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        4 days ago

        Ask Hiroshima and Nagasaki.

        In alphabetical order.

        Edit: oops, those are fission, my bad

        • Blue_Morpho@lemmy.world
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          4 days ago

          Those are fission. Fusion bombs don’t fuse uranium. They use a fission bomb to fuse Lithium.

              • peoplebeproblems@midwest.social
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                4 days ago

                I mean if we really want to be technically accurate here, the lithium is just a moderater for the hydrogen isotopes to fuse.

                But for me it gets fuzzy when looking at the reaction.

                LiD is 4 protons, 8 neutrons. Add a new neutron, and bam, you have 4 protons and 9 neutrons. But that’s where it gets weird to me. The lithium needs to decay or something into a tritium and dueterium which forces the tritium to fuse with the existing dueterium in the LiD molecule? Clearly the neutron has enough energy to transfer into one of the atoms to increase the chance of tunneling actually occuring.

                • ChickenLadyLovesLife@lemmy.world
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                  3 days ago

                  The only real purpose of the lithium deuteride is that it’s a dry, shelf-stable, room-temperature fuel. The very first hydrogen “bomb” (actually a building-sized device) used supercooled liquid hydrogen as the fusion fuel, but this was obviously not practical for a deliverable bomb.

                  • peoplebeproblems@midwest.social
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                    3 days ago

                    I get that part, it’s still the reaction I can’t wrap my head around mainly because I don’t understand how chemistry is any different than alchemy.

                    I know that lithium itself doesnt fuse to create He+T+D, and I know it can’t undergo fission. Since lithium isn’t left over, and lithium-6 and 7 are stable, does that mean the neutron with extremely high kinetic energy really knocks like two of the LiD mokecules into each other, causing dueterium -dueterium fusion resulting in He4, and the Li6 gets more neutrons that for it to be come unstable enough to decay into tritium or deuterium?

          • frezik@midwest.social
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            4 days ago

            Oh, they do, but not as the primary or secondary. You can wrap depleated uranium around the core to capture fast neutrons that are leftover from the rest of the process. Changing the number of layers is how you can dial in a desired yield.

      • sga@lemmings.world
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        4 days ago

        sadly black holes go to something like 42% conversion (source: some minute physics video i think)

        • hemko@lemmy.dbzer0.com
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          3 days ago

          That’s quite interesting. Is it because of the light produced when the materia starts spinning around in the accretion disk in very high speeds? I doubt hawking radiation would do anywhere near that much

          • sga@lemmings.world
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            3 days ago

            https://youtu.be/t-O-Qdh7VvQ

            No, It is actually the light produced that we can actually use as a energy source, the limiting thing is, before completely loosing its kinetic energy to frictional heat, stuff falls into black hole, from where we can not get anymore energy back. If black hole is stationary, then its 6%, and if its spinning (and assuming the fastest spinning theoretically possible) - 42% (spinning black holes are smaller and have smaller radius of no-return

            • hemko@lemmy.dbzer0.com
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              3 days ago

              Ahhh alright I was thinking the black hole converting mass to energy for itself, not as if we were to try utilize it

    • Redex@lemmy.world
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      4 days ago

      Whilst I get your point, their point is still valid in the sense that you just can’t extract that energy from gasoline in a more efficient manner than just burning it. For practical purposes, gasoline truly is that much less energy dense.

    • suoko@feddit.it
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      4 days ago

      For comparison:

      • Chemical combustion of uranium: ~4.7 MJ/kg
      • Nuclear fission of uranium-235: ~83.14 TJ/kg (or $ 83.14 \times 10^6 , \text{MJ/kg} $)
    • dalekcaan@lemm.ee
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      4 days ago

      In theory, yes. In practice, of those two only fission is currently viable.

    • Ledericas@lemm.ee
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      3 days ago

      If you can do nuclear fusion yea, it’s more efficient. Cold fusion has been a sci Fi thing for a while; they mostly moved on to antimatter-matter annihilation, and ZPE(seems to be a favorite for sg1)