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Wait, do people actually think Dyson swarms are a thing? The amount of time and energy needed to build them always seemed ridiculous to me. Especially as all yo

Wait, do people actually think Dyson swarms are a thing? The amount of time and energy needed to build them always seemed ridiculous to me. Especially as all you gain is energy (which hasn’t proven limiting) and you lose almost everything else (gravity and atmosphere for a start)...

mgolawala 5y ago
I am not at all well informed about this but I imagined a Dyson swarm would sort of grow and evolve organically over time. Not as an end goal in themselves. For example, if you start building space habitats (even if they are enclosed cylinders such that they hold an atmosphere and provide gravity via rotation) you need to put them somewhere. It makes sense to throw them in orbit around the star at some optimal distance (for example at 1AU +/- some amount), if you continue to put more and more such habitats around a star in similar orbits over time, in sufficient numbers, wouldn't they start to resemble a Dyson swarm?
- cletus 5y ago
  Think of it this way: a cloud is just water droplets suspended in the air. The air is transparent. Water is transparent. Yet... you can't see through clouds. That's essentially what a full Dyson Swarm looks like. People have modeled how many orbitals you'd need to achieve this and I believe that if you orbit them at 1 AU (plus or minus) the mean distance between them is still around 150,000km.
the8472 5y ago
> Especially as all you gain is energy (which hasn’t proven limiting) What? Civilization runs on cheap, abundant energy. Before the industrial revolution we had to use labor animals, slaves and the occasionally water and wind mill. Providing light was expensive. Global supply chains (transportation), aluminium smelting, fixing nitrogen for fertilizer or calcination for cement consume stupendous amounts of energy. If energy became cheaper then creating green fuel for airplanes and rockets, electrorefining all metals, desalination or perhaps mining and crushing olivine rocks for carbon sequestration would become more feasible. Whenever vertical farming is discussed here the main counter-argument boils down to energy not being cheap enough. It's hard to compete with the sun delivering it to plants for free.
- Grustaf 5y ago
  None of those things are necessary for civilisation, or radio communication. They just improve things on the margin. Besides, surely it must be simpler to build a fusion reactor on earth than harvesting enough material to cover the sun in solar panels. Would the solar system even have enough resources for that?
  - the8472 5y ago
    > None of those things are necessary for civilisation That's only true for low values of civilization. Even bronze age tech consumes more than hunter-gatherers which consume more than monkeys. > Besides, surely it must be simpler to build a fusion reactor on earth than harvesting enough material to cover the sun in solar panels. Dyson swarms sit higher on the kardashev scale than harvesting whatever you can get on a single planet. At some point waste heat rather than fuel will also become a real problem. Fusion reactors are ultimately thermal power stations, glorified steam engines. > Would the solar system even have enough resources for that? You'd start small with asteroids. And then disassemble some moons with shallow gravity wells. Which of course again requires stupendous amounts of energy just to move the material around but the sun still has billions of years left so there will be time to recoup that investment.
  - pie420 5y ago
    The sun is a large fusion reactor. Eventually you will run out of mass in the solar system to put in your fusion reactor, and then you'll resort to extracting energy from the natural fusion reactor. A Dyson sphere is a fusion reactor of sorts.
  - deleted 5y ago
    [deleted]
- LatteLazy 5y ago
  I don't want to doubt we will find some use for more energy but... I think I have all the energy I need to be honest. I don't lack for aluminium or even transatlantic flights (the most energy intensive think I could think of buying). If I really want to go to X I do. Price doesn't really bother me. Maybe we can use 10x the current supply so everyone can have my lifestyle. But that's still vastly less than a Dyson sphere would produce. For a long time energy was a limiting factor on human development. But I don't think that's true for the average westerner anymore. I want time off and less stress and relationships. Those mostly come down to social structures and information, not GJs...
cletus 5y ago
> Wait, do people actually think Dyson swarms are a thing? Yes, absolutely. The main reason is that building orbitals is largely an engineering problem. You need a material no stronger than stainless steel. If graphite is feasible, it allows you to build bigger orbitals but it's not necessary. Compare this to a lot of other proposed megastructures like space elevators, which would take a material to build that doesn't currently exist. Also, to be clear, we're talking about Dyson _Swarms_. This is the original design idea that was called Dyson Spheres but that name is often not used because people mistakenly think we're talking about a rigid shell that encompasses a star. That is not and never was the intent. It's also impossible for many reasons. A Dyson swarm is simply a collection of orbitals. The great thing about it is you can also build it incrementally. Note that since these are spinning orbitals they have (spin) gravity and atmospheres. Energy is absolutely a factor here.
- UI_at_80x24 5y ago
  >Also, to be clear, we're talking about Dyson _Swarms_. This is the original design idea that was called Dyson Spheres but that name is often not used because people mistakenly think we're talking about a rigid shell that encompasses a star. That is not and never was the intent. It's also impossible for many reasons. Thank-you for clearing this up for me. I made a post after you, but you addressed the issues that I discarded. I now know more then I did. Thanks!
- LatteLazy 5y ago
  How do such small objects maintain their atmospheres? Also, to remain in a stable orbit, wouldn't the spin force have to match the gravity of the star? So there would be no effective force left to provide gravity would there? (Similar to how people on the ISS are weightless despite still being within earth's gravity well).
  - pixl97 5y ago
    The vast majority of devices in a theoretical dyson sphere are energy collectors. These would be mostly flat with no atmosphere or gravity. Much larger 'space stations' could be built throughout the swarm that would have induced gravity or internal atmosphere.
UI_at_80x24 5y ago
I liked that Ringworld addresses this. What Dyson Sphere's excel at is hiding their location* and capturing 100% of a stars output. At those sizes, a civilization MUST have already conquered the energy problem. It'd be impossible to construct without "free energy", because you need to convert that energy into matter to make/engineer enough material to create a sphere the size of the Goldilocks zone. And as you said, you'd lose atmosphere & gravity* would be wonky. But to address the fine article, the equation was a thought experiment. We now have hard data on the number of stars that we've looked at that have planets. And of those we have a hard number that have planets in the habitable zone. The Drake Equation presumes that you guess TINY numbers for those values. Well using known numbers and extrapolating the number of possible worlds with intelligent life jumps from staggering large, to incomprehensible. As humans, we can barely communicate with others of our own species. Let's frame the problem another way. Put two Americans in a room. One is deaf, the other is blind. How long does it take for them to agree on what to eat for dinner? Context depends on language. We may have been bombarded by intelligent alien life for centuries; we just don't know that somebody is talking. *Everybody forgets about gravity.
- the8472 5y ago
  > A civilization MUST have already conquered the energy problem There possibly are ever more exotic applications that require more energy. Energy to matter conversion which you mention (and which also conveniently produces antimatter) requires very very large amounts of energy. The mass defect of the Tsar Bomba is merely 2.6kg, which also happens to be roughly equivalent the energy the sun that hits the whole planet each second. And then there are speculative things like the alcubierre drive or anything that involves moving entire stars.
- cletus 5y ago
  > I liked that Ringworld addresses this Just FYI, but the Ringworld as Larry Niven envisioned it simply doesn't work because no known or theorized material is remotely strong enough. To produce gravity a Ringworld needs to orbit the star. This produces centrifugal force that is tearing the ring apart. I believe around our Sun it would need to spin at about 1.2M mph [1]. [1]: https://www.bbc.com/future/article/20150609-will-we-ever-build-ringworlds#:~:text=Assuming%20that%20the%20ringworld%20shares,rotate%20at%20approximately%201%2C200%2C000mph https://www.bbc.com/future/article/20150609-will-we-ever-bui....

mgolawala 5y ago

I am not at all well informed about this but I imagined a Dyson swarm would sort of grow and evolve organically over time. Not as an end goal in themselves. For example, if you start building space habitats (even if they are enclosed cylinders such that they hold an atmosphere and provide gravity via rotation) you need to put them somewhere. It makes sense to throw them in orbit around the star at some optimal distance (for example at 1AU +/- some amount), if you continue to put more and more such habitats around a star in similar orbits over time, in sufficient numbers, wouldn't they start to resemble a Dyson swarm?

cletus 5y ago
Think of it this way: a cloud is just water droplets suspended in the air. The air is transparent. Water is transparent. Yet... you can't see through clouds. That's essentially what a full Dyson Swarm looks like. People have modeled how many orbitals you'd need to achieve this and I believe that if you orbit them at 1 AU (plus or minus) the mean distance between them is still around 150,000km.

the8472 5y ago

> Especially as all you gain is energy (which hasn’t proven limiting) What? Civilization runs on cheap, abundant energy. Before the industrial revolution we had to use labor animals, slaves and the occasionally water and wind mill. Providing light was expensive. Global supply chains (transportation), aluminium smelting, fixing nitrogen for fertilizer or calcination for cement consume stupendous amounts of energy. If energy became cheaper then creating green fuel for airplanes and rockets, electrorefining all metals, desalination or perhaps mining and crushing olivine rocks for carbon sequestration would become more feasible. Whenever vertical farming is discussed here the main counter-argument boils down to energy not being cheap enough. It's hard to compete with the sun delivering it to plants for free.

Grustaf 5y ago
None of those things are necessary for civilisation, or radio communication. They just improve things on the margin. Besides, surely it must be simpler to build a fusion reactor on earth than harvesting enough material to cover the sun in solar panels. Would the solar system even have enough resources for that?
- the8472 5y ago
  > None of those things are necessary for civilisation That's only true for low values of civilization. Even bronze age tech consumes more than hunter-gatherers which consume more than monkeys. > Besides, surely it must be simpler to build a fusion reactor on earth than harvesting enough material to cover the sun in solar panels. Dyson swarms sit higher on the kardashev scale than harvesting whatever you can get on a single planet. At some point waste heat rather than fuel will also become a real problem. Fusion reactors are ultimately thermal power stations, glorified steam engines. > Would the solar system even have enough resources for that? You'd start small with asteroids. And then disassemble some moons with shallow gravity wells. Which of course again requires stupendous amounts of energy just to move the material around but the sun still has billions of years left so there will be time to recoup that investment.
- pie420 5y ago
  The sun is a large fusion reactor. Eventually you will run out of mass in the solar system to put in your fusion reactor, and then you'll resort to extracting energy from the natural fusion reactor. A Dyson sphere is a fusion reactor of sorts.
- deleted 5y ago
  [deleted]
LatteLazy 5y ago
I don't want to doubt we will find some use for more energy but... I think I have all the energy I need to be honest. I don't lack for aluminium or even transatlantic flights (the most energy intensive think I could think of buying). If I really want to go to X I do. Price doesn't really bother me. Maybe we can use 10x the current supply so everyone can have my lifestyle. But that's still vastly less than a Dyson sphere would produce. For a long time energy was a limiting factor on human development. But I don't think that's true for the average westerner anymore. I want time off and less stress and relationships. Those mostly come down to social structures and information, not GJs...

cletus 5y ago

> Wait, do people actually think Dyson swarms are a thing? Yes, absolutely. The main reason is that building orbitals is largely an engineering problem. You need a material no stronger than stainless steel. If graphite is feasible, it allows you to build bigger orbitals but it's not necessary. Compare this to a lot of other proposed megastructures like space elevators, which would take a material to build that doesn't currently exist. Also, to be clear, we're talking about Dyson _Swarms_. This is the original design idea that was called Dyson Spheres but that name is often not used because people mistakenly think we're talking about a rigid shell that encompasses a star. That is not and never was the intent. It's also impossible for many reasons. A Dyson swarm is simply a collection of orbitals. The great thing about it is you can also build it incrementally. Note that since these are spinning orbitals they have (spin) gravity and atmospheres. Energy is absolutely a factor here.

UI_at_80x24 5y ago
>Also, to be clear, we're talking about Dyson _Swarms_. This is the original design idea that was called Dyson Spheres but that name is often not used because people mistakenly think we're talking about a rigid shell that encompasses a star. That is not and never was the intent. It's also impossible for many reasons. Thank-you for clearing this up for me. I made a post after you, but you addressed the issues that I discarded. I now know more then I did. Thanks!
LatteLazy 5y ago
How do such small objects maintain their atmospheres? Also, to remain in a stable orbit, wouldn't the spin force have to match the gravity of the star? So there would be no effective force left to provide gravity would there? (Similar to how people on the ISS are weightless despite still being within earth's gravity well).
- pixl97 5y ago
  The vast majority of devices in a theoretical dyson sphere are energy collectors. These would be mostly flat with no atmosphere or gravity. Much larger 'space stations' could be built throughout the swarm that would have induced gravity or internal atmosphere.

UI_at_80x24 5y ago

I liked that Ringworld addresses this. What Dyson Sphere's excel at is hiding their location* and capturing 100% of a stars output. At those sizes, a civilization MUST have already conquered the energy problem. It'd be impossible to construct without "free energy", because you need to convert that energy into matter to make/engineer enough material to create a sphere the size of the Goldilocks zone. And as you said, you'd lose atmosphere & gravity* would be wonky. But to address the fine article, the equation was a thought experiment. We now have hard data on the number of stars that we've looked at that have planets. And of those we have a hard number that have planets in the habitable zone. The Drake Equation presumes that you guess TINY numbers for those values. Well using known numbers and extrapolating the number of possible worlds with intelligent life jumps from staggering large, to incomprehensible. As humans, we can barely communicate with others of our own species. Let's frame the problem another way. Put two Americans in a room. One is deaf, the other is blind. How long does it take for them to agree on what to eat for dinner? Context depends on language. We may have been bombarded by intelligent alien life for centuries; we just don't know that somebody is talking. *Everybody forgets about gravity.

the8472 5y ago
> A civilization MUST have already conquered the energy problem There possibly are ever more exotic applications that require more energy. Energy to matter conversion which you mention (and which also conveniently produces antimatter) requires very very large amounts of energy. The mass defect of the Tsar Bomba is merely 2.6kg, which also happens to be roughly equivalent the energy the sun that hits the whole planet each second. And then there are speculative things like the alcubierre drive or anything that involves moving entire stars.
cletus 5y ago
> I liked that Ringworld addresses this Just FYI, but the Ringworld as Larry Niven envisioned it simply doesn't work because no known or theorized material is remotely strong enough. To produce gravity a Ringworld needs to orbit the star. This produces centrifugal force that is tearing the ring apart. I believe around our Sun it would need to spin at about 1.2M mph [1]. [1]: https://www.bbc.com/future/article/20150609-will-we-ever-build-ringworlds#:~:text=Assuming%20that%20the%20ringworld%20shares,rotate%20at%20approximately%201%2C200%2C000mph https://www.bbc.com/future/article/20150609-will-we-ever-bui....