As civilisations become more and more advanced, their power needs also increase. It's likely that an advanced civilisation might need so much power that they enclose their host star in solar energy collecting satellites. These Dyson Swarms will trap heat so any planets within the sphere are likely to experience a temperature increase. A new paper explores this and concludes that a complete Dyson swarm outside the orbit of the Earth would raise our temperature by 140 K !
The concept of a Dyson swarm is purely a hypothetical concept, a theorised megastructure consisting of numerous satellites or habitats orbiting a star to capture and harness its energy output. Unlike the solid shell of a Dyson sphere, a swarm represents less of an engineering challenge, allowing for incremental construction as energy needs increase. The concept, first popularised by physicist Freeman Dyson in 1960, represents one of the most ambitious yet potentially achievable feats of astroengineering that could eventually allow a civilisation to use a significant fraction of its host star's total energy output.
... The paper concludes that a Dyson sphere surrounding the sun would significantly impact Earth's climate. Small spheres positioned inside Earth's orbit prove impractical, either becoming too hot for their own efficiency or having too great an impact on solar energy arriving on our planet. While large spheres enable efficient energy conversion, they would raise Earth's temperature by 140 K, making Earth completely uninhabitable.
A compromise might involve creating a partial structure (the Dyson swarm) at 2.13AU from the sun. This would harvest 4% of solar energy (15.6 yottawatts, or 15.6 million billion billion watts) while increasing Earth's temperature by less than 3K—comparable to current global warming trends. It's still quite an engineering feat though, requiring 1.3×1023 kg of silicon.
[Source]: The Universe Today
[Journal Ref]: The photovoltaic Dyson sphere
(Score: 4, Informative) by pTamok on Saturday March 22, @10:21PM
Could you put the sup tags in to show this correctly as
It's still quite an engineering feat though, requiring 1.3×1023 kg of silicon.
Alternatively, use the Unicode superscript characters: U+00B2 - ² ; and U+00B3 - ³
(Score: 3, Touché) by looorg on Saturday March 22, @10:23PM (1 child)
When is Musk starting construction? DysonX.
(Score: 1, Touché) by Anonymous Coward on Saturday March 22, @11:22PM
That's so funny I forgot to laugh.
(Score: 3, Informative) by c0lo on Saturday March 22, @10:34PM (1 child)
Either use 1.3×10<sup>23</sup> or the UNICODE superscript 1.3×10²³
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by pTamok on Tuesday March 25, @03:17PM
If you have a system that cannot cope with super- and sub- scripts, it is possible to use 'E notation [wikipedia.org]' as well.
So it could be written as 1.3E23
That notation has a long history.
(Score: 5, Insightful) by corey on Saturday March 22, @11:34PM (14 children)
In my mind it’s a strange concept because I would think by that time, an advanced civilisation (humans) would have mastered nuclear fusion.
Also it assumes that electrical power consumption continually goes up. Not sure that’s valid too. And wouldn’t the civilisation be space faring by then?
(Score: 2) by c0lo on Sunday March 23, @12:56AM (11 children)
Courageous of you to assume one can safely beat the speed of light limit - you know the chemical bonds are based on the same EM interaction as the light, right?
If that limit is still applicable, by the time the Mayflower generation starships reach the destination, what do you do with the rest of population still trapped in the Solar system?
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 2, Insightful) by khallow on Sunday March 23, @03:14AM
Technically, humans are already space-faring. That is, they already have vehicles capable of moving through space. If you step up to living in space, for example, that's vastly easier than building and running a Dyson swarm.
Well, if you have the capability to build Dyson swarms, you probably have the capability to move trillions of people in those Mayflowers. There need not be a "rest of the population."
(Score: 3, Insightful) by corey on Sunday March 23, @04:05AM (8 children)
As khallow replied, I wasn’t saying humans would be travelling FTL, which I understand would require infinite propulsion. I meant interplanetary at least — Mars, Titan, maybe Europa. I just think that by the time humans would need to encircle the sun with archaic solar panels, we’d have better ways to generate electricity. Because it’s a long way (time) away.
(Score: 4, Informative) by c0lo on Sunday March 23, @07:00AM (7 children)
Yeah, naaah, mate. You won't need a Dyson-anything if you don't try to get out of the star system.
Because if you need a Dyson, some proper solar system rearrangements will be required. Some of the planets may go properly busted.
1.3×1023 kg of silicon is about all the silicon that Mars contains (27.7% * 6.39e23kg = 1.77e23kg) - so you'll need to destroy the entire Mars to do it or find an equivalent of it. If you go to "harvest" Mars, its gravitational binding energy is 5e30 Joules.
You will need to clean the asteroid belt, because 2.13AU is just where that belt starts. So maybe you can do better by using the cleanup material.
In addition to the harvesting energy, most of the silicon will be bound as silica - SiO2, which has a binding energy of 621.7 kJ/mol. With a molar mass of 60g/mol, to kick the oxygen out and keep only the silicon, you'll need 10.36MJ/kg with 100% efficiency. If you go on the thermal route to decomposition, expect efficiencies in the range of 5% to 20%; OK let's be generous 33% efficiency, which means 30MJ/kg.
So, the total energy expenditure only to get your 1.3e23kg of silicon is another 4e30 Joules.
How much "controlled fusion" you need to get 4e30 Joules?
The total Sun power output is 3.8e24W and consumes 6e8 kg/s of hydrogen to do that - so you'll need the equiv of 2weeks of entire Sun's output just to get your silicon
Assuming your controlled fusion has the same efficiency as the Sun, you will need about 6e14kg hydrogen going through your reactors. Don't ask me about the logistics of:
- building those reactors - superconductive magnets and the rare earths they need, you may need to dismantle Mars after all.
- putting those reactors in orbit
- gathering fuel to burn through them
- operating them - you know? Space may be defined as "cold", but the vacuum of space is heck of a thermal insulator (this is why the superconductors of your magnets won't be superconducting for long if you don't manage to vent the heat. Remember, radiative cooling only!)
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by shrewdsheep on Sunday March 23, @10:07AM (5 children)
I would guess that - like cathedrals of the past - dyson-anything contructions would be multi-generation efforts. Let's say a thousand years.
That being said, I agree that Dyson-anything as well as space-faring humans are completely irrelevant but for different reasons. The human condition is incompatible with living anywhere else but earth. There physiological, psychological reasons and more generally the incredible fragility of keeping of tiny parts of ecosystems being kept in isolation. Space-faring humans will therefore never happen. For dyshon-*, again, there is no motivation for humans to build anything like it. The equilibrium will have to be found on earth and can easily be found there. Over-population is the main pressure not energy.
I do believe that intelligence will eventually escape the solar system. This will only be possible in the form of robotic AI, however.
(Score: 4, Interesting) by c0lo on Sunday March 23, @01:33PM (3 children)
I'm not convinced humans can't evolve into a space-adapted subspecies - may not be able to set foot onto a planet but live quite healthy in space.
Now, that's a problem I'm afraid is far from trivial to solve - but it's an engineering problem.
But, to be honest, I'm more concerned of another thing, which doesn't pertain to engineering.
Extending the humanity beyond Earth will require quite an amount of people to work on a large program and coordinating it will require politics. Chances are this politics will start devolving in power politics soonish enough (2-3 generations at most).
On the other side, a space program will involve controlling huge (by human measures) amounts of energy - even if the space to extend humanity into is limited to the solar system.
Have a look on the today's world then put together "power politics" as motivation and "control over large amounts of energy" as means.
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by khallow on Sunday March 23, @02:17PM (2 children)
How long is a generation? Not a present day generation of say 20 or so years, but a future generation where humans have adapted themselves to living in space or elsewhere.
(Score: 2) by c0lo on Sunday March 23, @02:48PM (1 child)
2-3 generations will be shorter than the time required to establish the first independently-viable colony outside Earth; not enough Pokanokets out-there in the Solar system, I reckon.
Enough time for the humans to forget the lessons from their past, especially when the politics puts a pathological narcissist in power.
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by khallow on Sunday March 23, @03:13PM
Starting from when? If you're starting from now, then you have generations of the wrong duration.
(Score: 1) by khallow on Sunday March 23, @02:16PM
Never happen now. The future is a different story. No reason we couldn't a) make an earthlike environment in space (we already know how to generate artificial gravity via rotation and we can reduce the incredible fragility of tiny parts of ecosystems to credible durability), b) we can genetically engineer humans with a human condition compatible with space, and c) we can build cybernetics to engineering the human condition in the same way via that route.
My view on this is that a few hundred years ago, there would have been similar naysaying about human flight or modern telecommunication. Things change and we're pretty good at making them change.
(Score: 1) by khallow on Sunday March 23, @02:05PM
Like say Mercury? Better delta-v and solar influx is way better. And no, I wouldn't bother with 2.13 AU no matter what the story says. Close enough that you're barely solid is the better approach! As to the concern about incepting sunlight for Earth, that's far less of a problem than making sure that the makers of the Dyson swarm don't use it as a weapon of war.
(Score: 2) by mcgrew on Sunday March 23, @04:17PM
You can't go faster than light, but you can slow time down by going fast. That's exactly what Journey to Madness is about. If you can create a sustained 1g or better thrust you could leave the galaxy still alive, but no one else would still be alive. You could get to Sirius and back in twenty years, but a hundred years would have passed here by the time you got back. I'm not the first to write a novel about the time warp.
Einstein theorized it, and NASA proved it with two identical atomic clocks.
Impeach Donald Saruman and his sidekick Elon Sauron
(Score: 2, Insightful) by khallow on Sunday March 23, @01:36AM (1 child)
Their star(s) would be the largest fusion reactors in their system no matter how advanced they get - unless they're pulling material away from their star to make smaller stars/fusion reactors.
If you need metric tons of antimatter for your typical projects and you have a lot of projects, then I can see the need for a Dyson swarm.
(Score: 2) by corey on Sunday March 23, @06:30AM
Thanks. Maybe I should stop being lazy and read the article. :)
(Score: 4, Insightful) by dwilson98052 on Sunday March 23, @01:12AM (3 children)
...any species capable of building that would also have the ability to alter the orbit of their planet, moving it out far enough to negate the difference.
(Score: 2) by bzipitidoo on Sunday March 23, @01:39AM (2 children)
I have thought of this. The trouble with harvesting energy for use on Earth that would otherwise pass by Earth is that ultimately, it becomes heat. Despite the current ice house conditions, Earth's ability to absorb additional heat is not good, and projected to get worse. The ice house conditions are fragile. I get the impression that now the only reason Earth still has ice sheets is inertia, and that perhaps in another century, they will all be gone. Maybe some day, if we're still around, we'll put server farms in orbit or on the Moon and power them with solar, with the point of all that being to dump the waste heat anywhere but on Earth.
A thought I've had about this is that strangely, such technology could make Mars more habitable than Earth. Make Mars about 80 degrees C warmer, to bring it up to temperatures we find comfortable. On Mars, have all this harvested energy with which to do fun things before it becomes heat.
(Score: 1, Interesting) by Anonymous Coward on Sunday March 23, @01:59AM
> Despite the current ice house conditions, Earth's ability to absorb additional heat is not good
From what others have said before, absent so much greenhouse gas, the Earth can radiate a thousand more times energy than is necessary currently as black-body radiation into space. Cooling the earth would be no problem -- if we had the means to switch away from fossil fuels. Combining: relatively small amount of energy usage, on a global scale, with lower greenhouse gas concentration, the extra energy input unto the planet wouldn't be significant.
(Score: 2) by ledow on Monday March 24, @10:16AM
A civilisation capable of surrouding their sun at 4AU with energy-gathering panels won't be using that energy on Earth. They'll already be spread across the solar system, setting up orbiting stations, laying claim to entire orbits, etc. and hence that energy would just be spread out, same it was before, but now more useful.
(Score: 0) by Anonymous Coward on Sunday March 23, @01:41AM (1 child)
Is it from all the radiation reflected back by the satellites? Or from the heat generated by all the power we would be using?
(Score: 0) by Anonymous Coward on Monday March 24, @12:56PM
If all that energy was directed back to Earth it wouldn't be a lousy 140K increase. You would rapidly vaporise the planet. Dyson swarms utilise the energy either where it is collected, or elsewhere in the swarm. The increase in temp is just due to incidentally reflected light and heat.
(Score: 3, Insightful) by Ken_g6 on Sunday March 23, @04:04AM (1 child)
I think they're missing a trick. Individual satellites aren't going to pass between the sun and Earth very often. When they do, they can easily rotate so they block a minimal amount of sunlight, then rotate back into position to keep collecting solar power.
(Score: 2) by deimtee on Monday March 24, @01:02PM
The whole point of a Dyson swarm is to collect it all. The real answer is to have two partial layers, one inside the Earth's orbit that blocks just enough to compensate for the second one outside the Earth's orbit reflecting light and heat back.
That's if you are still bothering to keep the planet if you get to the point where you can build one. More likely you have disassembled it for materials.
One job constant is that good employers have low turnover, so opportunities to join good employers are relatively rare.
(Score: 4, Insightful) by theluggage on Sunday March 23, @09:19AM (2 children)
If you successfully capture a significant fraction of the Sun’s energy output (or generate a comparable amount of energy via fusion, antimatter, unobtanium, whatever) *and use that energy on Earth* then all that energy will end up as waste heat and boil the Earth anyway…. Even if the Earth was outside the sphere/swarm it will need some impressive planetary air conditioning…
Fusion and other magic “clean” energy sources might solve the immediate CO2 problem, but if you increase energy use exponentially to the sort of levels that Dyson et al imagine, then that energy won’t be going away after you’ve downgraded it to waste heat. I think most “Dyson” scenarios involve living on the sphere/swarm components where you can radiate away heat and/or turn energy into starship fuel. Exponential growth in a closed system doesn’t work, folks!
Someone should also do the math on covering the Sahara with solar panels (then using that energy)… that’s gonna change the climate too, folks!
On this planet we obey the laws of thermodynamics…
(Score: 3, Insightful) by Unixnut on Sunday March 23, @12:12PM (1 child)
Alas most people (including some "educated" ones) don't seem to understand that concept, which is why there is so much nonsense being pushed around in the world.
From the point of a Dyson swarm, we (Earth) orbit in a single plane around the sun, so if your Dyson panels are in a different plane it should not affect us very much (if at all). However the extra energy we bring to Earth would affect the climate as you mentioned.
As such it would be better for that captured energy to be used in Space, or redirected to another planet where the climate is already inhospitable for us (e.g. Mars), then we can have our mining and Industry over there and not impacting the Earth.
You would mainly have to think of how to send that captured energy across. Aside from trying to beam the light directly (the panels could be mirrors for example), you can convert the energy into some kind of liquid fuel that can be easily stored and transported to the planet for use.
(Score: 1) by khallow on Tuesday March 25, @12:17PM
First, because it's a Dyson swarm, it's intercepting a lot of sunlight. Earth would be in plane for that inception, assuming they didn't bother to maneuver the panels so that while they were in front of Earth (doesn't matter that much if they're elsewhere in the orbital plane), they were oriented to intercept least sunlight (that is, edge-on to sunlight while between Earth and Sun). The second problem is more intractable. You now have a vast cloud of warm and somewhat reflective objects, even when they're way out of plane with Earth's orbit. The Earth will see a bit of that redirected energy and that will raise the Earth's temperature at least significantly (assuming you aren't reducing regular sunlight heating to counterbalance of course) - the minimum they were talking about was comparable to almost triple today's warming of Earth (since that magic date of 1850). The worst would boil Earth's oceans away. And that's merely incidentally radiation with zero power beamed towards Earth. Most of it would be lower frequency than photosynthesis could exploit BTW.
For all the talk above, keeping Earth at the proper level of sunlight wouldn't be as hard an engineering problem as building and operating the swarm. The real problem would be what is being done with that power. There would be multiple ways to destroy Earth (including as people have noted before, actual physical destruction of the planet itself) with a Dyson swarm, intentionally, or through negligence and indifference.
(Score: 4, Funny) by jman on Sunday March 23, @10:05AM
On the sphere: Panel, panel, panel, vent. Panel, panel, panel, vent...