Martin wrote:

Nick M V Salmon wrote after HOW MANY WHISKEYS 'N' RUM? (;-)):

[...]

Laterz: Bugger, another thought I just have to put on 'paper' - if
that point at the centre of a toroidal black hole is under sufficient
 decompressive stress, could it open a 'portal' to another 'where'
...

The stuff of many a film of fiction.

Getting a black hole to be truely torroidal is the first problem. The
next is how to go where you want to go rather than just to the same
(gravitational) potential energy level on the opposite side.

(Assuming that you don't get ripped apart leaving just the filament of
material that went through the EXACT centre as you whizzed through. Ouch.)

On a slightly less extreme scale:

Is there any advantage in using the moon to 'sling-shot' probes into our solar system rather than using big boosters and a long time?


Regards,
Martin