Re: OT: Dyson's Disaster

> Date:         Wed, 5 Dec 2001 14:43:35 -0500
> From: Andreas Johansson <and_yo@...>
>
> Anton Sherwood wrote:
> >But there is a force from the sun on each part of the sphere.  The
> >forces are globally balanced, but the local mass doesn't know that. ;)
> >
> >If the sphere is infinitely rigid, of course, that's not a problem.
>
> I may be wrong, but I think the sphere'll act as an arch, and therefore
> won't need to be extremely strong to survive that effect.
Yes, it will work as an arch, or rather a dome --- but it will still
flatten just a bit if you push on the top. And since the initial
curvature is quite small, you can get substantial absolute movements
of the surface without compressing the material very much.

Hmmm... the speed of seismic waves varies from 3 to 13 kilometers per
second. If the sphere is as large as the orbit of the Earth, it'll
take a year for opposite spots to interact --- and centuries for the
sphere to stabilize its shape if the forces acting on it change.

Better keep that sun in the center, or you'll get seasick.

Lars Mathiesen (U of Copenhagen CS Dep) <thorinn@...> (Humour NOT marked)