A black hole and white hole are perfect opposites as described by the equations for relativity. A black hole can only pull matter or energy in, and a white hole can only expel matter or energy. The effect of a funnel traveling through curved space before reaching the event horizon gives the possibility that this funnel could reach to any point in space because this funnel's length is not relative to the distance it covers in normal space. Therefore, because of the potential energy resources of a black hole and the potential for "shortcuts" through space I believe that black holes could be used as a self-sustaining transit system trough space.
II. Possible Energy Sources in Black Holes.
1. Three most probable energy sources.
There have been many different approaches taken by science fiction to theorize on the possibility of obtaining energy from a black hole. The three that have the most conventional possibility of success are the extraction of energy from rotation, particle emission, and mass. .
2. Rotational Energy.
When a star collapses into a black hole it retains 99% of the original energy it had at the time of its creation. This also includes the rotational energy build up over time. When a star is born, it doesn't magically start spinning in place, the normal rotation of a star is slowly increased by gravity fields pulling it in different directions. Even forces that perceivably have no effect like that of a comet all have a cumulative effect in rotating the star. Over billions of years of small tugs in one direction or another the star builds up a rotational velocity, which can be tapped because its magnetic field rotates as it does. .
Therefore because a black hole would retain this rotational energy at the time of implosion it is possible to use this energy. Because of the much reduced size and infinitely increased gravitational force it would be possible to construct around a black hole a type of generator.
