Re: Planets and Moons

I accidently sent two emails to Kris offlist. I'm concatenating them
together for this. I've added two notes to clarify what I mean.

Damn GMail and its screwing about with Reply-To!

Kris Kowal wrote:

>>What's always puzzled me is what you would do with the Earth's biosphere
>>while you were constructing this outsized beach-ball, and whether it
>>wouldn't be too fragile to survive more than a couple of hundred years,
>>which would seem a bit of a waste, having gone to all that effort.
>
>
> Sorry about the misspelling.  There are more fundamental problems with
> a Dyson Sphere.  Inside a spherical shell, there is no tendency to
> gravitate toward the surface, so the atmosphere would not 'cling' to
> the wall.  From every point in the sphere, the ground beneath causes
> exactly the same ammount of attraction as the sum attraction of all
> the mass above.  There's also the problem of 'stellar wind'.  Earth's
> magnetic field shirks this particle radiation.  In a Dyson Sphere, it
> has no path of escape.
You could always build on the outside, any use the energy collected from
inside to power lighting and heating systems outside.

The atmosphere *might* be able to cling to this if the hollow sphere has
enough gravity[1] to get everything else to cling to it.

Or even have a hollow bit in the shell, maybe about 1 mile deep. This
hollow could contain the atmosphere, and the wall along the outer side
could have the heating and light equipment[2].

And a Dyson Sphere isn't an actual sphere. It's more of a ring-type
thingy.

K.

Notes:

[1] Assuming that the solar gravity would be enough to hold everything,
     which I doubt. Mind you, there's no harm in doing this in fiction...
[2] Possibly using mirrors and filters to distribute the light and heat,
     and remove any harmful radiation.