One of the biggest areas of speculation in interstellar science is whether there may be Dyson Spheres somewhere out there in the cosmos. A Dyson Sphere is a giant construct around a star, designed by its creators to capture as much of the star’s energy as possible in order to optimize that civilization’s development and longevity.
But if you think about it, a Dyson Sphere is illogical, because it assumes a star is a stable, predictable source of energy—when it really isn’t. And if you want to lengthen the lifespan of your race, building a permanent construct around an essentially unstable star is just about the last thing you want to do.
A star like our sun is a beast of chemicals caught in a constant state of fusion burning. But there is nothing constant about its output, despite the fact that it may seem pretty constant over a few light years away and a few thousand years of observation. In fact, our own observations of the Sun in just the last few decades has revealed irregular and unpredictable outputs, producing more and less energy, radiation and energetic particles all the time. We have found correlations between these irregular outputs and changes to our atmosphere and temperature, impacting ice ages and regional habitability. Studies suggest that we could see even larger irregularities in the future, which could strain our existing planet’s viability significantly.
Besides this irregular output, we know that a star has a limited shelf life. In approximately 5 billion years, the sun will begin the helium-burning process, turning into a red giant star. When it expands, its outer layers will consume Mercury and Venus, and reach Earth. Every other star will similarly burn out at some point, either going nova in the process, or collapsing upon itself, perhaps turning into a black hole.
So, imagine you’re an alien race that wants its species to live forever: Would you commit mind-boggling resources and time to creating a giant habitat around a star that’s only going to die eventually and leave you with a mind-bogglingly huge lifeless shell?
I don’t think so. It would make more sense (and consume a lot less in time and resources) for that alien race to shoot for full mobility, in order to move from star to star as needed. They would become a space-faring race, building either groups-small or populations-large spacecraft and living off space like nomadic tribesmen, transiting to solar systems whose star could provide them energy, and perhaps planets that they could mine for needed resources; and when the star no longer suited them (about to nova or collapse, or simply putting out too many unpredictable flares of energy and particles), they would gather enough energy and resources to sustain them as they head out to the next system.
Stephen Hawking once said about alien travelers: “I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach.” Blatant name-dropping aside, I agree with his idea of interstellar nomads, though not with his impression that they would be star-faring marauders: Because they would surely need to conserve their energy and resources as a matter of survival, and as war is an energy- and resource-intensive business, they would surely avoid any efforts, like wars, that unnecessarily waste valuable resources. It’s unlikely that our wild, dangerous, oxygen-rich planet would be anything but an incredible curiosity to them; but scattered throughout our system are greater resources, mostly easier to get, than those on Earth (including water, you sci-fi movie hacks). They might arrive in our solar system and safely plunder the asteroids and a few of Saturn and Jupiter’s moons, but they’d probably just monitor Earth from orbit or ground-based outposts, likely to add alien life knowledge (and wildlife footage) to their libraries. Maybe, if we’re lucky, they’d leave an outpost behind when they move on, and we might learn something about them.
This point is so important that it should be added as a variable to the Drake Equation (the formula used to predict the possibility of other intelligent life in the cosmos). One element in the Drake Equation is the state of a world’s habitability. But if you take into account that a race may have evolved and departed a planet or system before it became uninhabitable, then the habitability variable must be expanded to include planets that may at one time have been habitable enough for long enough to spawn a race, even if it is no longer habitable. So habitability becomes a limited span, long enough for a race to develop far enough to be able to leave for a new star system… but that also expands the possible number of habitable planets.
This also suggests that, if a race became star-faring, that they no longer need a single habitable planet… but they will periodically need to replenish some supplies from resources they can potentially find on multiple planets at different times. So a new variable needs to be added: That of a star system with enough accumulated resources to help sustain a transitory race as it moved from system to system. And its resources don’t need to be comprehensive: If a space-faring race can accumulate resources A, B and C in one system, and wait until they transit to another system to replenish resources D, E and F… again, you’ve expanded the number of planets that may support the survival of a civilization.
Such alterations to the Drake Equation would suggest a higher possibility of neighbors out there, perhaps in places we may not have looked before, since they may be able to harvest resources from a wider array of systems than we have previously assumed. Or possibly in transit from one system to another, and not likely to be wasting valuable resources on beaming signals about looking for other races; at least, not until they reach an oasis that will sustain them for long enough to do some local exploring for the next system to transit to.
This last point could be potentially interesting, too: For a space-faring race that moves from system to system, harvesting resources as needed, they may someday see the Solar System as a valuable oasis to visit. But for those who are worried that they may feel the need to—I dunno—attack the Earth, subjugate or kill us, and steal our resources… be assured that most of this system’s most valuable resources can be more easily obtained from the many outer planets, moons and asteroids of the solar system, and those resources would not be contaminated with the pesky and unpredictable organic life infesting this planet at present. Because we already know the aliens wouldn’t be big on unpredictability… it makes it much harder and more energy-intensive to survive.
So, I think we can stop looking for Dyson Spheres out there; I doubt there will be many races, capable of building them, who would not be smart enough to know how wasteful they would be. Instead, we should be looking for potential space-oasis systems, and the nomadic ships transiting between them.
They could even turn up in our system, respectfully keeping their distance as they harvest resources from the outer planets and trying to avoid the locals.
please explain how building a dyson sphere would be so wasteful? also what is your understanding of robotics, physics, quantum mechanics and astrophysics?
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“Would you commit mind-boggling resources and time to creating a giant habitat around a star that’s only going to die eventually and leave you with a mind-bogglingly huge lifeless shell?” That’s what, in a nutshell, I call wasteful.
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I know, I know… late to the party. But here’s my after-the-fact 2 cents.
So, essentially: “Why would you build a gigantic solar array or a house when the sun is going to explode in just 5 billion more years?”
You’re making assumptions about practicality without understanding that if it *could* build a megastructure out of need, it would clearly be able to make such an undertaking practical and worthwhile, with regard to time.
If it could build the entire megastructure in a couple thousand years, and keep it going for a few billion years, it’s almost certainly worthwhile.
You’re applying long-term thinking to a short-term project. There are places where that works, but this probably isn’t one of them.
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I’d argue that making dyson spheres would work for them for two reasons: (1) they can build them to be taken apart and reconstructed around multiple stars, as reusable as their ships; and (2) a spacefaring race would have the mobility to pick out the youngest stars to optimize the amount of useful energy they’d get from said stars, rather than just sitting in one place.
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I’d counter that ships are so much more significantly energy-efficient than a Dyson Sphere, and much more easily moved to new stars as needed; and it would make more sense building a ship now than jury-rigging a piece of a Dyson Sphere into a ship later.
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I agree with you. Dyson spheres always seemed a little odd to me. If you’re technologically advanced enough to build something like that, it seems like you wouldn’t really need it. However, given what we know about how illogical humans can be, I’m not willing to rule out the possibility that someone somewhere might have built one of these things.
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It’s a valid point, James; after all, we’ve flown to the Moon just to prove we could do it, buy fast-food salads with more calories than their hamburgers, currently idolize an amateur porn queen’s family and may elect a racist misogynistic elitist baby-hater for a president. So I suppose anything is possible.
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I would like to add my thoughts to this speculation. We are simply yet to young and dumb to understand what is going on around us. More advanced, space-faring race could manipulate with matter on a massive scale, lets say stabilize their star or even create their own with predictable and calculated output and simply refueling it after. This advanced race could be in the state where they don’t care about resources and seek only for greatness… there is a lot of sci-fi around describing this.
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Jaroslav, if you’re suggesting that an alien race would build an artificial star, then build a Dyson sphere around it for the same reason that humans built the pyramids, just to prove they could… well, maybe, but I think any alien race with those kind of resources is also smart enough to know when pure display is not only pointless, but counter-productive to the entire species. But I can’t argue with the point that a species might be as irrational as we are, and therefore could be capable of the most ridiculous actions imaginable.
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The concept of a real Dyson sphere in a relativistic universe is laughable at best. The concept of a real Dyson sphere in a relativistic universe is laughable at best. On top of everything written here, Consider this: A generous estimate of the average density of terrestrial planets is 4 grams per centimeter. Using this density, building a 1cm thick Dyson sphere at the radius of Earth would require approximately 1.125 x 10^31 grams of solid matter (not counting gases and liquids). A VERY generous guess, assuming we could extract ALL of the rocky material (not nearly enough metals) in the Solar system, would leave us with something like 1.841 x 10^31 grams of terrestrial matter. That is a stone dyson sphere approximately 1.6cm thick.
Now think about the implications of such a contraption: the gravity that it would generate… not nearly enough to hold us to the “ground.” The heat trapped inside would be a nearly perfect greenhouse (minus the heat dissipated/radiated into space outside the sphere). There wouldn’t be any matter left over to build houses, buildings… anything. Certainly not enough to build the facilities required to turn that light and heat into energy fast enough to mediate the temperature.
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Sorry about the “extra” first sentence. I know some of you will assume I haven’t thought of scientific advancement and come back with that… but all of you star trek geeks (yes… I am one of them too), need to sit back and realize how much of science fiction violates the laws of physics. Matter/energy transporters for example (not the best example I know but 90% of science fiction relies on similar unrealistic devices)… even if it were possible to convert all of the matter contained in a single body into energy, that amount of energy would be enough to run the entire planet for around two months on our planet’s current energy budget. Now think of what it would take to pipe that amount of energy from one place to another using a single “computer” or “transporter” equipment within seconds…
I am sure that there are many wonders that have yet to be performed through the progress of technology and science; but physics does have its limits.
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I find the core complaint rather silly: that it’s not worth the bother with a sun that’ll “only” last for some 5 billion years. That’s such a mind-boggingly HUGE amount of time that I’m really not sure what this point is even trying to say! Even if you assume say, hundreds of thousands of years for completion, the return you get on it ’til it runs out would be far greater.
(Also I see no reason not to also treat that the Dyson sphere isn’t as the “spaceship”-if you have finished such a material gobbling construct, hurling it towards the next solar system sounds like a better idea than restarting from scratch.)
A more sensible objection could have been to address the amount of material to create this structure in the first place. Given that the sun contains 99.9% of ALL the mass in the Solar System (the planets, the belts, and even the Oort Cloud only make up 0.01%) you’d be hard pressed to find enough material to finish this project without dippijg into the Sun itself.
We might of course consider whether any species will ever be capable of reaching the scale where it can even benefit from that much energy or out it to use.
If we could capture even a tiny fraction (say, a billionth) of that total we’d never have to rely on fossil fuel again!
But by definition the Dyson spere thought experiment presupposes a civilization that has already reached that level (Kardashev scale and all that). My problem with this article is that it seems to be stuck thinking about a lower scale where, yes, building a Dyson sphere would not be sensible – but neither would hopping to a new sun just yet.
I guess the dilemma boils down to what would come first.
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What can I say? I have to assume an advanced civilization is not going to commit such vast resources to a structure that will only die when the sun finally dies… as opposed to just moving to another system in the first place. To me, practicality is a sign of an advanced civilization… not waste.
You’re also right that a civilization should be able to function much less power than an entire star puts out. Capture just a tiny part of that, and you have enough energy to take you to another star. And I see becoming a mobile civilization to be much more practical, reliable, and controllable long-term than digging in to a star that has a limited shelf-life.
But what do I know? I just write here.
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You are probably picturing a gargantuan metal shell entirely enclosing a star, which is the traditional picture of a Dyson Sphere. It’s true that something like this would be totally impractical to even hold together, let alone the material cost. However, a real Dyson Sphere would look nothing like this. It would be a swarm of hundreds of thousands or even millions of satellites, each carrying a microscopically thin mirror. This way, power can be simply reflected to wherever it is needed, and instead of a massive and wasteful shell of metal, you have satellites that are easy to build and replace. And when the star does eventually burn out, you simply leave the satellites in place or take them with you, whichever is easier. A civilisation that has had a Dyson Swarm for that long would probably not care about material cost much, since planets can be deconstructed for materials on such a grand scale that it makes the resources needed to make a Dyson Swarm look like pocket change.
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Though, yes, that design does make more sense than a solid sphere, I still believe that it would be smarter to move on and find a more habitable home… or become space nomads and remain system-free… than to use your resources to cling to a dying star and system, since logically you know you’re going to have to leave eventually anyway.
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