Re: Dyson shell redux

From: Michael Lorrey (mlorrey@datamann.com)
Date: Thu Mar 15 2001 - 15:38:38 MST

impossible getting done;

an article on solar sails being tested..... Marvin Minsky, eat my
shorts....

Anders Sandberg wrote:
>
>
> > You probably need to run Buckytube cables around the
> > the thing to provide the strength necessary to support
> > micrometeorite punctures and resist the pressures resulting
> > from solar flares. Lots of calculations to do here to
> > study the feasibility I suspect.
>
> It is also likely that we need to take active countrol into account.
>
> A quick estimate: Solar flares produce an increase of solar output
> around DL=3.83e-9 (based on
> http://lepjas.gsfc.nasa.gov/~thorpe/thesis/chapter5.html). This would
> mean a change in force of DF=DL*L/(4 pi c r^2). Assuming the canonical
> 1 AU Dyson, I get DF=1.77e-14 N. Not much. But assuming that it pushes
> over half the surface area of the dyson, I get 2.5e9 N total force,
> which is 2.6e-3 N/m along the "equator". Seems manageable.
>
> During a solar cycle the luminosity varies with at least 0.1%, but
> this is isotropic. This is more serious: DF=4.66e-9 N, 263,000 times
> more. This means the tension along a great circle would be 684
> N. Still sounds within the realm of possibility to handle even using
> current materials, although we need to make the cables very light for
> the entire structure to act as a statite.
>
> > I don't like Ander's application of all of the mass in the
> > solar system to this application because it doesn't seem
> > necessary. (I also get about twice as much material as he
> > does to work with in the solar system -- something we need
> > to resolve at some point...).
>
> We can always spend some time at Extro5 going through it.
>
> > A principle you can try to work with is how do you
> > make the best use of the available energy with the
> > smallest amount of material possible. If you only
> > use a fraction of the available material for Jeff's
> > Dyson *SPHERE* Lite, then Ander's can use the rest of
> > it for building a Nutronomium-Brain (I forget what he
> > calls these).
>
> Jupiter brains, or ISOs. But I guess the different models will have
> individual names. I suggested Ouranos, Zeus and Chronos, but in
> reality they will be called Economy, DeLuxe, Business Edition etc :-)
>
> > Now the question is what kind of a good computer architecture
> > can you fit on top of a Dyson Shell Lite. The one that comes
> > to mind for me is a 2-D cellular automata. I.e. no 1-cm^3
> > rod-logic CPU's, instead you cover the surface with
> > very thin CPU's that only communicate with their nearest
> > neighbors. Now, what kind of calculation that is good for
> > I don't know
>
> Running extensive 2D partial differential equations?
>
> I would suggest that connunications through the interior of the sphere
> using laser would make it much more versatile. The delays are long,
> but it would be able to run more like a small world network (2+1 D?).
>
> > Lets try in the discussions to be careful with terms --
> > a "shell" would be lots of nested orbiting satellites
> > (like a Matrioshka Brain), a "sphere" would be a standard
> > fully contiguous surface. These ideas have been misunderstood
> > for too long and its time to set them right.
>
> I agree! Maybe we should call this system of linked solar sails a
> Dyson net?
>
> --
> -----------------------------------------------------------------------
> Anders Sandberg Towards Ascension!