[ExI] Will Advanced Civilizations Ever Build Dyson Spheres?

[Ben Zaiboc]

On 09/11/2024 00:14, BillK wrote:
> Building Dyson structures around a star will require a huge amount of material.
> (Stars are very big!).
> And it has to be metal-rich material.
> Dismantling asteroids and even planets would be necessary just to get
> a thin partial shell around a star.
> This would also have risky orbital effects.
> I think that's why they suggest pushing planets and large asteroids
> into the habitable zone and doing terraforming might be easier.
> (though still an enormous task).

I thought that the idea of Dyson Spheres (such as you see in science 
fiction shows) had been dismissed long ago as being impractical, not to 
mention dangerous, and physically impossible (nothing would have the 
required tensile strength). As far as I'm aware, even Dyson himself 
didn't mean that, but rather what we now call Dyson Shells, comprising 
many small (relatively small) objects in concentric orbits at all 
inclinations, eventually shrouding an entire star, and intercepting all 
its energy.

In any case, I don't think moving and terraforming whole planets is ever 
going to be a good idea. Planets are a colossal waste of mass. If you 
have the technology, and insist on remaining biological, I'd think 
mining the planets and asteroids for material to create many large 
rotating habitats would be a much better idea. You could perhaps end up 
with a Dyson Shell of habitats. Planets aren't just a waste of mass, 
they are very poor at capturing energy from your local star (and if you 
make trillions or quadrillions of solar power plants to solve that 
problem, you might as well be living in them instead of being trapped at 
the bottom of a gravity well on the surface of a planet).

It's all moot, though, because I'm pretty sure that any substantial 
space-faring civilisation will have to be based on non-biological 
machine intelligences (uploads, AIs, or some hybrid of both). Biology 
and space just aren't compatible. So that changes the whole equation, 
and planets become vast reservoirs of raw materials imprisoned in deep 
gravity wells, and rotating habitats become irrelevant, except perhaps 
as zoos.

Perhaps a signature of an advanced civilisation would be a star with no 
planets, asteroids and other such rubble, with a pretty uniform 
distribution of relatively small orbiting objects instead, which would 
probably be pretty difficult to spot, so it might just look like a bare 
star, perhaps with a non-standard emission spectrum.

Maybe the Tabby-class stars aren't the ones with aliens at all, maybe 
it's the boring ones that we don't take any notice of.

-- 
Ben
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