14 Apr 2013
We know that toroidal stars can exist because we have built small ones on Earth : Tokamaks . We expand things a bit to stellar scales. Then use Schwinger limit to stabilise local Tokamaks .
1.Tokamaks are constrained by magnetic fields due to inner plasma flow (see Appendix I ) and outer magnetic fields caused by orbiting electrons in constrained orbits (electromagnets or ordinary magnets)
2.Large scale stellar toroids use the advantage of the inverse square effect distance (1/R^2) to manage the magnetic fields to get dynamic stability .
3.Think Highly charged Plasma Shepherd Planets (analogous to electrons in smaller apparatus) .
4.There exist stable orbits for toroids , but they loop through the toroid , through the spindle and around the outside .
This is an advantage , as the Plasma Planet can replenish lost charge .
A Plasma Planet is essentially a fairly coherent packet of plasma .
5.All this is highly unstable and would have to be managed by a High Civilization .
6.Can something like it be naturally stable ?
It seems vaguely possible . See Appendix II .
7.Singularity at the core of the toroid :
See http://en.wikipedia.org/wiki/Schwinger_limit . If the electric field goes over 1.3 x 10^18 V/M , then space goes non-linear .
A sort of singularity . An interesting experiment . Can actually be done on Earth Tokamaks . Maybe one of the reasons they are so unstable .
8.How to stabilise a Tokamak :
Deliberately induce Schwinger Singularities in the core axis of tokamaks .
A type of Stochastic Resonance. We increase control by increasing randomness . A well known and widely used evolutionary and industrial technique . Greatly enhanced by putting some NeuralNetworks and GeneticAlgorithms in the loop .
I suspect that that even without them , there would be major improvements on the axis side of the tokamak plasma .
9.Why would a High Civilization bother to build toroidal stars ?
9.1 For the hell of it .
9.2 Art .
9.3 Manufacturing large singularities , worm holes and exotic matter on huge scales .
9.4 War .
9.5 Trying for a Naked Singularity .
Or any combination or reasons unguessable .
That was fun !
A bit of fluff , with a nice possible pay-off in cheap energy .
Join the Schwinger Generation !
The term "safety" refers to the resulting stability of the plasma; plasmas that rotate around the torus poloidally about the same number of times as toroidally are inherently less susceptible to certain instabilities.
Stable Bound Orbits of Massless Particles around a Black Ring
(Submitted on 1 Feb 2013)
We study the geodesic motion of massless particles in singly rotating black ring spacetimes. We find stable stationary orbits of massless particles in toroidal spiral shape in the case that the thickness parameter of a black ring is less than a critical value. Furthermore, there exist nonstationary massless particles bounded in a finite region outside the horizon. This is the first example of stable bound orbits of massless particles around a black object.