<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
On 09/11/2024 00:14, BillK wrote:<br>
<blockquote type="cite"
cite="mid:mailman.71.1731111265.11245.extropy-chat@lists.extropy.org">
<pre>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).</pre>
</blockquote>
<br>
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.<br>
<br>
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).<br>
<br>
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.<br>
<br>
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.<br>
<br>
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.<br>
<pre class="moz-signature" cols="72">--
Ben</pre>
</body>
</html>