Dyson Spheres make no sense. They offer many disadvantages and few advantages over simply having a nearly unlimited number of self contained orbital colonies.
On a side note I think the Kardashev scale is completely silly. It has three levels but it’s very unlikely that any species anywhere in the universe is in any of them. Level 1 doesn’t make much sense as it involves basically covering your entire planet in solar panels. Level 2 is even more silly since it involves building a Dyson Sphere, and Level 3 is pure space opera.
It’s not hard to think that given the way our planet wasted 240 million years on evolutionary local maxima like Dinosaurs that some other civilizations might have beaten us to the punch by a few million years. In fact across the entire universe or even the galaxy we have to assume that forms of life have long since beaten us to the punch on intelligence, hence the Fermi Paradox.
But I’m a firm believer that FTL travel is effectively impossible, and thus the distances between solar systems is too much of a hurdle to cross. Basically by the time you’ve developed the technology to make it possible you are well past the point where it would be helpful. You would be spending an almost unimaginably large amount of resources to send something into the complete unknown on a project that won’t bear any fruit for hundreds or thousands of years at the earliest and has an extremely high chance of failure and extremely little chance of payoff. The usual argument is that you’ll run out of resources in your home solar system, but again this kind of ignores the scale of the problem and the idea that population need not grow exponentially without bounds and that recycling won’t be a solved problem (it will have to be for interstellar travel anyway).
As a fantasy thought experiment it’s valid. But from a practical standpoint the idea that humans would be harnessing 100,000 our current energy level in 100 years seems wacko. To get something like that you’re talking about cold fusion reactors in every car or something. It’s not even clear that level of energy consumption would be good for the planet, the waste heat further exacerbating the global warming problem. These are the kinds of assumptions mathematicians make from oversimplified models that assume exponential growth without bound.
Lets do another thought experiment. I once killed a fly when I was a kid, lets say 30 years ago. Had I not killed that house fly how many more flies would there be in the world today? A fly lays about 500 eggs over its lifetime and has a gestation period of about a month. So because I failed to kill that fly there are an additional 425795984000815071991005371624730884824659673431068160092505009184640
882874555213628503688372735690194809084517275552538119458169595866930
159197111953065261976984894788296990472248136886563906880329432274226
290379426362875392442219890654087066650390625000000000000000000000000
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000000 flies in the world today.
This is 510955180800978086389206445949677061789591608117281792111006011021569
059449466256354204426047282828233770901420730663045743349803515040316
191036534343678314372381873745956388566697764263876688256395318729071
548455311635450470930663868784904479980468750000000000000000000000000
000000000000000000000000000000000000000000000000000000000000000000000
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0.000000 kg of living fly mass.
In practice unbounded exponential growth never occurs. Even if your civilization is extremely clever and has access to titanic sources of energy and materials you slam into the laws of thermodynamics.
The missing mass in the Universe is tourists that we have been “adblocked” from because we aren’t advanced enough yet. BlackmatterBnB is going to make Apple look just silly.
When our sun goes nova, red dwarf suns will have hardly started their lives. Red dwarf suns are not good places to orbit because they have flares which could strip the atmosphere off your planet. However, a tidally-locked planet might have life in the twilight zone where it might ride out the worse flares.
If you want to look for alien mega engineering, I suggest you look for a red dwarf star that never flares.
Isaac Arthur’s Youtube site is priceless for discussion of these kind of issues. He has a bit of a speech impediment which makes my wife crazy, but after a little bit you stop noticing. He has impressive insight and his presentation is very understandable. “Two thumbs up!”
Every species keeps expanding and increasing their use of power and improving their technology, until they build a working holodeck. They realize they have something where everyone can have literally anything they can imagine. At that point they stop expanding and eventually all die of exhaustion and dehydration.
I’ve considered what a Dyson Sphere might look like to an outside observer. Assuming the alien species can’t defeat the laws of thermodynamics it would look roughly like a red giant of the same diameter. All of the energy from the sun has to go somewhere, and about the only place for it to go is out into space via radiation. So your Dyson Sphere has to radiate away that full sun’s worth of energy constantly, which means the outside would likely glow strongly in infrared.
This is an interesting though experiment. If we built a Dyson Sphere around the sun with a radius of 1AU, how much energy per square meter would it need to radiate to maintain thermal equilibrium? How hot would a black body radiator need to be to dump that much energy into space? Someone must have done the math on this already.
I agree. Whenever I hear about Dyson Spheres I cringe. I firmly believe any civilization advanced enough to build a Dyson sphere, is advanced enough to not need one.
