By the time your civilisation is taking advantage of black holes, it’s large enough that even a small temperature difference can scale to quite a bit of negentropy. Further, you don’t have to be in orbit, you can build a Dyson shell around the hole at such a distance that the surface gravity is one g. (Or several shells, if people prefer different levels of gravity.) Then there’s no orbital velocity to deal with. (And in any case, you could brake by tidal friction and extract some entropy that way.) Or to be shorter, why are you objecting to the practical details of a thought experiment? Nothing about the game theory relies on black holes or the particular exponent 2; it could just as well be mass^1.5, and the analysis would remain the same although the numbers would change a bit.
How is a Dyson sphere anything other than “in orbit”? Do you not know how they are supposed to work? Incidentally, Dyson spheres are a pretty silly idea as well. Slightly more realistic are rings—e.g. see my http://timtyler.org/the_rings_of_earth/
There are multiple types of Dyson sphere. Dyson’s original vision, a swarm of satellites, would be in orbit, but the popular version more commonly seen in fiction—a solid shell—would not, any more than the Earth orbits its own core (although any one point on the shell could plausibly be said to orbit the centre, provided the sphere is spinning).
A solid Dyson sphere is a dumb idea, the dynamics are unstable. See Niven’s essay on the dynamics of ringworld for the problems, and realize a sphere would be even worse. I don’t remember whether he discussed that in “Bigger than Worlds” or in an essay specifically on building Ringworld, he did discuss the dynamics problems in the novels as well.
By the time your civilisation is taking advantage of black holes, it’s large enough that even a small temperature difference can scale to quite a bit of negentropy. Further, you don’t have to be in orbit, you can build a Dyson shell around the hole at such a distance that the surface gravity is one g. (Or several shells, if people prefer different levels of gravity.) Then there’s no orbital velocity to deal with. (And in any case, you could brake by tidal friction and extract some entropy that way.) Or to be shorter, why are you objecting to the practical details of a thought experiment? Nothing about the game theory relies on black holes or the particular exponent 2; it could just as well be mass^1.5, and the analysis would remain the same although the numbers would change a bit.
How is a Dyson sphere anything other than “in orbit”? Do you not know how they are supposed to work? Incidentally, Dyson spheres are a pretty silly idea as well. Slightly more realistic are rings—e.g. see my http://timtyler.org/the_rings_of_earth/
There are multiple types of Dyson sphere. Dyson’s original vision, a swarm of satellites, would be in orbit, but the popular version more commonly seen in fiction—a solid shell—would not, any more than the Earth orbits its own core (although any one point on the shell could plausibly be said to orbit the centre, provided the sphere is spinning).
A solid Dyson sphere is a dumb idea, the dynamics are unstable. See Niven’s essay on the dynamics of ringworld for the problems, and realize a sphere would be even worse. I don’t remember whether he discussed that in “Bigger than Worlds” or in an essay specifically on building Ringworld, he did discuss the dynamics problems in the novels as well.
So you have to expend a bit of energy moving it back to the midpoint every so often. What are attitude jets for?
In fantasy novels, you mean?