[ExI] Dyson Sphere? Why? Just move planets into Habitable Zone.

[Keith Henson]

On Tue, Sep 26, 2023 at 12:23 PM BillK via extropy-chat
<extropy-chat at lists.extropy.org> wrote:>

snip

> The article and their paper “Making Habitable Worlds: Planets Versus
> Megastructures,”   <https://arxiv.org/pdf/2309.06562.pdf>
> does consider using laser arrays for moving planets.
>
> They make the point that to get enough material to build a Dyson
> Sphere you would have to dismantle most of the planets anyway and move
> the construction material to the habitable zone.

Maybe, but I doubt it.  I have not seen or set up the model, but I
suspect building in the computational zone is far more likely.

> Compared with that
> task, just moving a suitable sized planet or asteroid seems much
> easier.

Please try to keep track of the scales involved.  Earth is about 6 x
10 ^24.  The asteroid Bennu is around 7.3 x 10 ^10.

Moving a planet with a laser is about 10 ^14 more difficult.

> That also avoids all the problems associated with a Dyson
> Sphere that they discuss.
>
> They seem to be considering expanding to multiple times the population
> of Earth, so that would require a lot of real estate. Much more than a
> few space colonies. Although they could have small colonies as well.

The classic calculation about this is that O'Neill-type colonies
constructed from asteroids could provide about 2,000 times the area of
Earth.  That assumes, of course, human-type bodies that need air,
gravity, food, etc.

If you are trying to provide living space for biological humans,
piling the matter up to provide gravity is just a horrible way to do
it.  Using the tensile strength of materials to enclose spinning
habitats is far more efficient.

Keith
>
>
> BillK
>
> _______________________________________________
> extropy-chat mailing list
> extropy-chat at lists.extropy.org
> http://lists.extropy.org/mailman/listinfo.cgi/extropy-chat