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Dyson spheres are just inane.... sorry but they don't make sense. Any advanced form of civilization that can build one, probably figured how to do fusion effi
by ardit33 5y ago
Dyson spheres are just inane.... sorry but they don't make sense.
Any advanced form of civilization that can build one, probably figured how to do fusion efficiently locally and doesn't have to build these insanely inefficient energy harversters.
Keep in mind that the sun is very inefficient at energy release.
Dyson sphere prediction is like predictions in the 1800s how we would have coal and steam powered airships to travel around.
The reality is that steam via coal fire is too inefficient. Coal is just too heavy. Jet fuel is much more efficient/energy dense and not need to build giant airships.
Same with any advanced civilization. Dyson spheres just don't make sense, but they sure make good sci-fi movies/stories for the gullible.
- AprilArcus 5y agoThe ingredients for fusion reactors (deuterium, tritium and helium-3) are rare, not fully reacted intermediate byproducts of the proton-proton cycle that powers the sun. The likeliest case for a Dyson Sphere civilization would be some sort of solar powered Gray Goo von Neumann replicator.
- ardit33 5y agoIn theory you can fuse up to Iron.... the last stage of stars. You are not limited to just Hydrogen.
- tapas73 5y agoI assume that some of fusions done by the star are net energy consumption (i.e. not usable for energy production)
- ncmncm 5y agoYou assume wrong. Anything beyond iron is made in a supernova, i.e. in the last moments before it is not really a star at all, anymore.
- chii 5y agotakes a star's worth of gravitational force to push atoms like those together in the core to produce fusion. To reproduce such heavier elements in fusion reactors on earth would require, likely, a much higher energy than the output.
- ncmncm 5y agoThe ingredients for the most primitive, low-tech, hayseed fusion reactors are sort of rare. But anybody with any sophistication at all has no need for such primitive processes. They fuse plentiful regular hydrogen, helium, and, not to be wasteful, whatever they get from fusing those, too.
- empiricus 5y ago"do fusion efficiently locally" - with what? The vast majority of available fuel is in the stars. Dyson spheres are different than planet size civilization. For planet size civilization, with population in the order of billions/trillions ppl, local fusion is probably good enough. But for populations a billion times bigger, so billions of billions of ppl, you need dyson spheres, or alternatively, a way to destroy stars and get the raw hydrogen - probably harder to do.
- ncmncm 5y agoHint: Jupiter is made mostly out of hydrogen. Saturn too. Uranus and Neptune, if those get used up. Also plenty of helium, maybe even more useful. Also: the Pacific, Atlantic, Indian, and Arctic oceans are made of water, which has hydrogen in it. Also all of the Antarctic and Greenland ice, the Great Lakes, Caspian Sea, Lake Baikal, and Lake Victoria.
- akvadrako 5y agoJupiter is much smaller than the Sun, so it isn't really relevant what it's made of.
- ncmncm 5y agoIt is right there, completely unused, and not too hot to get close to. Most likely you would use up Neptune first, and save Jupiter for later.
- csee 5y agoWhy wouldn't they do fusion locally but also build a Dyson sphere? Doing only the former produces less energy than doing both the former and the latter. The view that they wouldn't do both is premised on the assumption that they won't need or want that much energy, combined with the assumption that the problem of disposing of the waste heat makes the extra energy not worthwhile.
- ncmncm 5y ago
- sgillen 5y agoWouldn’t the theoretical maximum output of a Dyson sphere (the entire output of a star) dwarf that of doing fusion yourself locally?
- ncmncm 5y agoIf you were using that much energy you would have the much bigger problem of disposing of all the waste heat afterward. You could not do that close to a star.
- freemint 5y agoNot necessarily as some stars are wasteful (use energy to fuse bigger atoms) or have material in the core it can't fuse. If you are just concerned with energy output per mass you can do better artificially in theory
- TheDudeMan 5y agoIt is not very meaningful to talk about the efficiency of something that is already running and needs no more fuel for the next billion years.
- pengaru 5y agoIt's worth noting "Dyson Sphere" is a product of sci-fi literature. Freeman Dyson himself only described an "artificial biosphere" in some paper he published, sci-fi authors mistook him literally (or were just being creative). He wasn't even describing anything resembling a physical sphere surrounding a star. He speaks to the subject in this excellent interview playlist, link is to the specific Dyson Sphere part: https://www.youtube.com/watch?v=GPB775_BZlw&list=PLVV0r6CmEsFzDA6mtmKQEgWfcIu49J4nN https://www.youtube.com/watch?v=GPB775_BZlw&list=PLVV0r6CmEs...
- jallen_dot_dev 5y agoPresumably if your super-advanced civilization needed more energy than could be fused from all the matter in a planet, you would have to get it from a star.
- ncmncm 5y agoOr use a bigger planet.
- fullstackchris 5y agoPresumably if you are a super-advanced civilation, you would get power from what would appear to us mere primates as essentially thin air, in a fashion we can't even fathom. "Any sufficiently advanced technology is indistinguishable from magic."
- jallen_dot_dev 5y agoSo a Dyson Sphere is inane, but energy from nothing isn't? Got it.
- fullstackchris 5y agoI'm right here with you, love the haters too that downvote you. The real takeaway is simply this: we don't (and can't) KNOW what type of energy advanced civilizations will have (and we might not even be able to understand it if we saw it!), and collective scientific time is much better spent on things that we DO know, like searching for bio markers similar to earth.
- denton-scratch 5y ago> the sun is very inefficient at energy release I'm not clear what is meant by "inefficient at energy release". Does that mean that the in the process of energy release, some of the energy is converted into heat? I.e., more energy?