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Always have to comment on the meme Dyson spheres posts with the following: has anyone ever thought, for one second, that a civilization capable of building thes

Always have to comment on the meme Dyson spheres posts with the following: has anyone ever thought, for one second, that a civilization capable of building these massive energy systems would actually be capable of generating energy in other different ways that we can't even imagine? This whole "Type I, II, III" civilization crap is stupid because it is based off one paper, of one guy, who had a creative idea. Props to him for the creativity, but millions of scientists every day have possibly creative ideas about space fairing civilizations. Its like sci-fi novels creeped into real science. Literally ape brain to just "wrap a star and capture its energy!" I think most people "like" the idea because it's so tangible. But that doesn't make it any more or less likely that it actually exists or makes sense.

rini17 5y ago
I think it's not only about energy generation but what would massive civilization without dyson spheres imply: 1. sidestepping thermodynamic laws - to allow massive energy use without detectable waste heat and/or 2. sidestepping time lags - so that the system does not need to be bunched as closely together as possible to allow for efficient communication and flows of material
- TheOtherHobbes 5y ago
  Dyson Spheres are fundamentally unphysical. The stability constraint on a complete sphere turns out to be less of a problem than it might seem, but there are still huge issues with stresses - Sphere Quakes. And before you can build a full Sphere you have to build a partial Sphere. Which is where stability will really kill you. Dyson Swarms might be more practical, but you still have a computability problem because you have an insanely huge number of objects in orbit and you somehow have to keep them from colliding with each other. Not so much a three body problem as an n body problem. With a built-in light lag delay of (at least) minutes. I'm not sure if anyone has modelled that, but it would be hilarious if the computing and station-keeping power requirements turned out to be a significant proportion of the available energy,
  - rini17 5y ago
    But you did not exhaust all the options. What about spherical constellation of energy gathering sails that stay mostly in place? Can autonomously maintain their position with help of solar wind.
    - perihelions 5y ago
      Or even pure radiation pressure. They balance out somewhere around 10^-3 kg/m^2; thinner than that and you have a solar sail.
    - PeterisP 5y ago
      > spherical constellation of energy gathering sails that stay mostly in place? Wait, what? You can't have a spherical constellation of unconnected stuff that mostly stays in place, that's not how orbits work. You can have a single orbital ring, but a sphere consisting of many circular orbits would have these orbits intersect with very large relative movement. If you're thinking about non-rotating constellation where the gravitational pull is balanced by solar wind, the problem is that they have gravitational interaction with each other and the planets so it's inherently unstable, they would "want to clump up" and as soon as they do, the balance is disrupted as the same mass has less solar pressure and it starts to fall into the sun.
      - rini17 5y ago
        To me it sounds like "flight heavier than air is impossible!!!!". Why would a device that has 1kW/m2 at its disposal at all times, be fundamentally unable to counteract gravitational interactions? We are not talking about planetary gravity wells here but much weaker ones.
- edgyquant 5y ago
  It’s probably just that colonizing the entire galaxy is really hard and no society ever has an economic need to. Populations don’t expand exponentially forever, the recent explosion is an effect of the industrial revolution, and any species that gets a certain size breaks up into subspecies and starts competing with each other. There could very well be individual dyson swarms out there and we haven’t seen them or haven’t realized that’s what they are. But building them around every star in the galaxy is something I’ll never understand why it’s taken as a given.
ben_w 5y ago
Frequently; that comes up in basically every Issac Arthur video on the topic. Unless such a civilisation can dump the waste heat as something other than infrared light or send that waste to somewhere other than the visible universe, it’s still extremely visible.
ncmncm 5y ago
The odds that anybody smart enough to be able to build such a thing would not be smart enough to recognize what a bad idea it is, is closer to zero than any mere human can conceive of.
- kragen 5y ago
  People smarter than you, like Freeman Dyson, have thought otherwise. More generally, a human putting long odds on what anybody much smarter than mere humans would do is self-evidently a way to lose bets. Can you imagine a dolphin or a crow successfully predicting the outcome of the US's withdrawal from Afghanistan?
  - ncmncm 5y ago
    Any crow, dolphin, or half-wit would have predicted US failure in Afghanistan. Donald Rumsfeld was Secretary of the US DoD at the time of the invasion. There is no public evidence that he predicted failure. Freeman Dyson never proposed building anything even vaguely like what is called a Dyson Sphere, and was famously irritated at having it attributed to him.
    - abecedarius 5y ago
      > Dyson had also proposed that the search for extraterrestrial intelligence (SETI) programs should “search for sources of infrared radiation” to “accompany the recently initiated search for interstellar radio communications.” https://www.inverse.com/science/how-many-dyson-spheres-are-in-the-milky-way https://www.inverse.com/science/how-many-dyson-spheres-are-i... I remember some discussion of this point in his autobiography. He wasn't talking about the Star Trek version, but certainly the intercept-all-the-sunlight constructions we're talking about.
      - ncmncm 5y ago
        Anyway, intercept-much-of-the-sunlight. It would be seriously impractical to arrange to intercept radiation leaving a star at high latitudes. And, being made of trillions of independently-orbiting tree-like things, there would be as many small gaps where native starlight would squeak out.
akvadrako 5y ago
Probably not. Energy is (at least to a high approximation) a conserved resource and stars are the most massive objects around besides black holes.
- TaylorAlexander 5y ago
  Based on our understanding of science. But 200 years ago the idea of having a conversation with someone 1000 miles away seemed quite impossible. Is it so hard to imagine that out of the possibly hundreds of millions of civilizations in the Milky Way, someone has found a way to extract energy from the universe in a way which seems physically impossible to us? I’m always very open to the idea that there could be a lot of physics we don’t understand yet. We could be at 0.1% of an understanding of the basic laws of the universe. I’m not saying I think that is likely or unlikely, but I do think it is possible.
  - gerikson 5y ago
    > But 200 years ago the idea of having a conversation with someone 1000 miles away seemed quite impossible In 1822 the Chappe optical telegraph had been in use since the Revolution, and the electric telegraph was ~20 years away. You'd have had to be singularly unimaginative not to envision an eventual extension to instantaneous voice.
    - TaylorAlexander 5y ago
      Ah, I guess I was referring specifically to radio transmission. You could say 400 years ago if that matters. A distant civilization could be 1 million years ahead of us.
larksimian 5y ago
Eh, it's typical retrofuturism type stuff, extending current technologies quantitatively rather than trying to predict categorical changes in available tech. Also the issues of dyson spheres aren't that bad. they could for instance channel the heat loss energy in a narrow beam out of the galactic plane so at least they'd be hard to spot by other galactic observers.
ansible 5y ago
OK, let's talk about energy generation for a minute. If we assume there exists some completely new physics, then... that could be anything. Advanced civilizations could take on any form. We can speculate all day about magic and elves too. If we don't assume any new physics and / or thermodynamics, then that constrains the discussion a lot. We have two basic ways of generating a lot of power, fission and fusion. Fission uses fissile materials, which are relatively rare, not just on Earth, but in the Universe at large. There's plenty enough for us at our current energy generation needs, but not nearly enough for a galaxy spanning civilization. That leaves us with fusion. Fusion reactors, as currently conceived use Helium-3 or something like that. There's enough of that around the solar system to power a civilization for a long time, even though the mass of oddball elements like Helium-3 make up a very tiny fraction of the total mass of the solar system (which is mostly the Sun with a smidgen of Jupiter). Most of the solar system's mass is plain hydrogen: one proton and one electron. Is it possible to fuse most / all of this mass in the solar system? Yes. We won't go into the details, but trying to fuse regular hydrogen (regular protons) together is highly impractical outside of the core of a star. Preferably a red dwarf type star which can more completely burn its fuel than our own Sun will, and live a lot longer to boot (a trillion years vs. ~10 billion for the Sun). So now we're talking about some kind of solar collectors, and if you want to collect _all_ the energy from a star, you want a sphere of some sort. Or a swarm of objects in orbit achieving the same effect. Hence Dyson sphere / swarm.
- raverbashing 5y ago
  > and if you want to collect _all_ the energy from a star, For what? What are you doing with it? Not to forget the fact that all energy used eventually turns into heat. All of it (with the exception of electrochemical transformations). You're bringing all of that into Earth you're cooking everybody alive. How are you bringing that energy from the sphere to (wherever place)? Putting solar panels on Earth itself works much better. Heck, make a Dyson sphere on Earth (facing outside), that makes more sense.
  - ansible 5y ago
    It is typically assumed that by the time you are making a Dyson swarm, that most life exists digitally. And spread out through the solar system. So in the best case scenario, you are powering computronium, upon which trillions of sophonts live out their digital lives. Hopefully doing some science, or at least playing some interesting games. A vast distributed network. In the worst case scenario, Blockchain and spam emails. Either way, people will put that energy to use. With a Dyson swarm, energy is received on the inside, towards the star, and heat is radiated outward. Lower power systems can run off the heat radiation of the inner swarm similarly. It is all eventually released as very low level heat, but diffused across the entire outer surface of the swarm. No hotspots... because someone would come along and use it. The Earth would also likely be deconstructed by this time, so don't worry about the biosphere, there won't be any.
edgyquant 5y ago
I definitely agree with you. I’m not a physicist but I did watch a ton of pop sci growing up and saw so much stuff about Dyson sphere, Fermi paradox, etc. I got so bored of it and hate how it drags down most discussions about potential alien life etc. The Fermi Paradox itself was supposed to proof we’ve got something wrong, not that we’re alone in the universe and something scary lurks. I think the answer may be that most civilizations never need or want to colonize everything in sight. It could also be political: no species gets to the level of being able to build structures like this without breaking up into competing polities. We think about colonizing everything because we’re still in the mode of a creature who evolved on a planet and spread out everywhere. It’s probably the case that with fusion dyson swarms aren’t used due to the opportunity cost of building them. In 1-200 years we’ll find the idea of surrounding the sun with metal as laughable as there being canals on Mars.
voldacar 5y ago
I agree. A hyper-advanced race would probably want to disassemble the star and use its hydrogen for something more efficient than the main-sequence nuclear process, which is pretty wasteful.
joe_the_user 5y ago
I fully agree with the sentiment. Speculation what form future tech takes should have be broad and uncommitted. * Given our current knowledge, Dyson Spheres are essentially impossible (just lesser-known point is that unlike planet, full Dyson Sphere or Ring World would not be attracted to the star that it would be built around, so it would have to be guided to move with it - see Larry Niven's Ring World Engineers). * What a civilization would do with all the energy, whether it would want it, etc are other unknowns. As you say, turning one person's clever idea into a whole research program at the very least neglects other great scifi novels.

rini17 5y ago

I think it's not only about energy generation but what would massive civilization without dyson spheres imply: 1. sidestepping thermodynamic laws - to allow massive energy use without detectable waste heat and/or 2. sidestepping time lags - so that the system does not need to be bunched as closely together as possible to allow for efficient communication and flows of material

TheOtherHobbes 5y ago
Dyson Spheres are fundamentally unphysical. The stability constraint on a complete sphere turns out to be less of a problem than it might seem, but there are still huge issues with stresses - Sphere Quakes. And before you can build a full Sphere you have to build a partial Sphere. Which is where stability will really kill you. Dyson Swarms might be more practical, but you still have a computability problem because you have an insanely huge number of objects in orbit and you somehow have to keep them from colliding with each other. Not so much a three body problem as an n body problem. With a built-in light lag delay of (at least) minutes. I'm not sure if anyone has modelled that, but it would be hilarious if the computing and station-keeping power requirements turned out to be a significant proportion of the available energy,
- rini17 5y ago
  But you did not exhaust all the options. What about spherical constellation of energy gathering sails that stay mostly in place? Can autonomously maintain their position with help of solar wind.
  - perihelions 5y ago
    Or even pure radiation pressure. They balance out somewhere around 10^-3 kg/m^2; thinner than that and you have a solar sail.
  - PeterisP 5y ago
    > spherical constellation of energy gathering sails that stay mostly in place? Wait, what? You can't have a spherical constellation of unconnected stuff that mostly stays in place, that's not how orbits work. You can have a single orbital ring, but a sphere consisting of many circular orbits would have these orbits intersect with very large relative movement. If you're thinking about non-rotating constellation where the gravitational pull is balanced by solar wind, the problem is that they have gravitational interaction with each other and the planets so it's inherently unstable, they would "want to clump up" and as soon as they do, the balance is disrupted as the same mass has less solar pressure and it starts to fall into the sun.
    - rini17 5y ago
      To me it sounds like "flight heavier than air is impossible!!!!". Why would a device that has 1kW/m2 at its disposal at all times, be fundamentally unable to counteract gravitational interactions? We are not talking about planetary gravity wells here but much weaker ones.
edgyquant 5y ago
It’s probably just that colonizing the entire galaxy is really hard and no society ever has an economic need to. Populations don’t expand exponentially forever, the recent explosion is an effect of the industrial revolution, and any species that gets a certain size breaks up into subspecies and starts competing with each other. There could very well be individual dyson swarms out there and we haven’t seen them or haven’t realized that’s what they are. But building them around every star in the galaxy is something I’ll never understand why it’s taken as a given.

ben_w 5y ago

Frequently; that comes up in basically every Issac Arthur video on the topic. Unless such a civilisation can dump the waste heat as something other than infrared light or send that waste to somewhere other than the visible universe, it’s still extremely visible.

ncmncm 5y ago

The odds that anybody smart enough to be able to build such a thing would not be smart enough to recognize what a bad idea it is, is closer to zero than any mere human can conceive of.

kragen 5y ago
People smarter than you, like Freeman Dyson, have thought otherwise. More generally, a human putting long odds on what anybody much smarter than mere humans would do is self-evidently a way to lose bets. Can you imagine a dolphin or a crow successfully predicting the outcome of the US's withdrawal from Afghanistan?
- ncmncm 5y ago
  Any crow, dolphin, or half-wit would have predicted US failure in Afghanistan. Donald Rumsfeld was Secretary of the US DoD at the time of the invasion. There is no public evidence that he predicted failure. Freeman Dyson never proposed building anything even vaguely like what is called a Dyson Sphere, and was famously irritated at having it attributed to him.
  - abecedarius 5y ago
    > Dyson had also proposed that the search for extraterrestrial intelligence (SETI) programs should “search for sources of infrared radiation” to “accompany the recently initiated search for interstellar radio communications.” https://www.inverse.com/science/how-many-dyson-spheres-are-in-the-milky-way https://www.inverse.com/science/how-many-dyson-spheres-are-i... I remember some discussion of this point in his autobiography. He wasn't talking about the Star Trek version, but certainly the intercept-all-the-sunlight constructions we're talking about.
    - ncmncm 5y ago
      Anyway, intercept-much-of-the-sunlight. It would be seriously impractical to arrange to intercept radiation leaving a star at high latitudes. And, being made of trillions of independently-orbiting tree-like things, there would be as many small gaps where native starlight would squeak out.

akvadrako 5y ago

Probably not. Energy is (at least to a high approximation) a conserved resource and stars are the most massive objects around besides black holes.

TaylorAlexander 5y ago
Based on our understanding of science. But 200 years ago the idea of having a conversation with someone 1000 miles away seemed quite impossible. Is it so hard to imagine that out of the possibly hundreds of millions of civilizations in the Milky Way, someone has found a way to extract energy from the universe in a way which seems physically impossible to us? I’m always very open to the idea that there could be a lot of physics we don’t understand yet. We could be at 0.1% of an understanding of the basic laws of the universe. I’m not saying I think that is likely or unlikely, but I do think it is possible.
- gerikson 5y ago
  > But 200 years ago the idea of having a conversation with someone 1000 miles away seemed quite impossible In 1822 the Chappe optical telegraph had been in use since the Revolution, and the electric telegraph was ~20 years away. You'd have had to be singularly unimaginative not to envision an eventual extension to instantaneous voice.
  - TaylorAlexander 5y ago
    Ah, I guess I was referring specifically to radio transmission. You could say 400 years ago if that matters. A distant civilization could be 1 million years ahead of us.

larksimian 5y ago

Eh, it's typical retrofuturism type stuff, extending current technologies quantitatively rather than trying to predict categorical changes in available tech. Also the issues of dyson spheres aren't that bad. they could for instance channel the heat loss energy in a narrow beam out of the galactic plane so at least they'd be hard to spot by other galactic observers.

ansible 5y ago

OK, let's talk about energy generation for a minute. If we assume there exists some completely new physics, then... that could be anything. Advanced civilizations could take on any form. We can speculate all day about magic and elves too. If we don't assume any new physics and / or thermodynamics, then that constrains the discussion a lot. We have two basic ways of generating a lot of power, fission and fusion. Fission uses fissile materials, which are relatively rare, not just on Earth, but in the Universe at large. There's plenty enough for us at our current energy generation needs, but not nearly enough for a galaxy spanning civilization. That leaves us with fusion. Fusion reactors, as currently conceived use Helium-3 or something like that. There's enough of that around the solar system to power a civilization for a long time, even though the mass of oddball elements like Helium-3 make up a very tiny fraction of the total mass of the solar system (which is mostly the Sun with a smidgen of Jupiter). Most of the solar system's mass is plain hydrogen: one proton and one electron. Is it possible to fuse most / all of this mass in the solar system? Yes. We won't go into the details, but trying to fuse regular hydrogen (regular protons) together is highly impractical outside of the core of a star. Preferably a red dwarf type star which can more completely burn its fuel than our own Sun will, and live a lot longer to boot (a trillion years vs. ~10 billion for the Sun). So now we're talking about some kind of solar collectors, and if you want to collect _all_ the energy from a star, you want a sphere of some sort. Or a swarm of objects in orbit achieving the same effect. Hence Dyson sphere / swarm.

raverbashing 5y ago
> and if you want to collect _all_ the energy from a star, For what? What are you doing with it? Not to forget the fact that all energy used eventually turns into heat. All of it (with the exception of electrochemical transformations). You're bringing all of that into Earth you're cooking everybody alive. How are you bringing that energy from the sphere to (wherever place)? Putting solar panels on Earth itself works much better. Heck, make a Dyson sphere on Earth (facing outside), that makes more sense.
- ansible 5y ago
  It is typically assumed that by the time you are making a Dyson swarm, that most life exists digitally. And spread out through the solar system. So in the best case scenario, you are powering computronium, upon which trillions of sophonts live out their digital lives. Hopefully doing some science, or at least playing some interesting games. A vast distributed network. In the worst case scenario, Blockchain and spam emails. Either way, people will put that energy to use. With a Dyson swarm, energy is received on the inside, towards the star, and heat is radiated outward. Lower power systems can run off the heat radiation of the inner swarm similarly. It is all eventually released as very low level heat, but diffused across the entire outer surface of the swarm. No hotspots... because someone would come along and use it. The Earth would also likely be deconstructed by this time, so don't worry about the biosphere, there won't be any.

edgyquant 5y ago

I definitely agree with you. I’m not a physicist but I did watch a ton of pop sci growing up and saw so much stuff about Dyson sphere, Fermi paradox, etc. I got so bored of it and hate how it drags down most discussions about potential alien life etc. The Fermi Paradox itself was supposed to proof we’ve got something wrong, not that we’re alone in the universe and something scary lurks. I think the answer may be that most civilizations never need or want to colonize everything in sight. It could also be political: no species gets to the level of being able to build structures like this without breaking up into competing polities. We think about colonizing everything because we’re still in the mode of a creature who evolved on a planet and spread out everywhere. It’s probably the case that with fusion dyson swarms aren’t used due to the opportunity cost of building them. In 1-200 years we’ll find the idea of surrounding the sun with metal as laughable as there being canals on Mars.

voldacar 5y ago

I agree. A hyper-advanced race would probably want to disassemble the star and use its hydrogen for something more efficient than the main-sequence nuclear process, which is pretty wasteful.

joe_the_user 5y ago

I fully agree with the sentiment. Speculation what form future tech takes should have be broad and uncommitted. * Given our current knowledge, Dyson Spheres are essentially impossible (just lesser-known point is that unlike planet, full Dyson Sphere or Ring World would not be attracted to the star that it would be built around, so it would have to be guided to move with it - see Larry Niven's Ring World Engineers). * What a civilization would do with all the energy, whether it would want it, etc are other unknowns. As you say, turning one person's clever idea into a whole research program at the very least neglects other great scifi novels.