Huh, I'd be curious to see that source. I know he somewhat recanted the idea of a Dyson sphere, as it is completely impractical even with unimagined technology (re: tensile strength of the materials, and preventing such a megastructure from falling into the sun whenever a rock hits it). But he later proposed the idea of a Dyson swarm, an extremely large array of solar-sucking satellites orbiting the sun as an idea that's theoretically possible even with today's technology.
theothermkn|6 years ago
In short, there's no practical way to stick an atmosphere, much less a civilization composed of life forms that depend on gravity, to the inside of the sphere, even if the other engineering challenges could be overcome.
* One thing that's suddenly more interesting to me now is if the space at any point is being "pulled" equally in all directions, resulting in zero force, or if the bends in space-time cancel out. In the limit, for example, could you "tear" space-time inside a dense enough and/or heavy enough shell of matter?
papreclip|6 years ago
there is zero space-time curvature within the sphere, it's "flat", so there's no force. nothing is "cancelled out", force is the derivative of energy with respect to space. it's like a 3d pedestal (or rather, a cylinder excavated from the earth with a flat bottom)
aeorgnoieang|6 years ago
Why not spin the sphere? Given the immense surface area, it wouldn't even matter that the centripetal force would only be strongest around the 'equator'.
So, the plan would be:
1. Create a giant rotating sphere around our Sun.
2. Create a ring world around the 'equator' of the inside of the sphere (i.e. a ring of walls high enough to hold in the resident's preferred atmosphere).
3. Install solar panels everywhere else.
4. Profit!
ellis0n|6 years ago
Freestyler_3|6 years ago
https://en.wikipedia.org/wiki/Dyson_sphere#cite_note-3