Home > Einstein-Rosen Bridge

This makes passage through this bridge and hence into another universe a mathematical possibility.

Actually the geometrical property exists in all black holes; it is called an Einstein-Rosen bridge only for static or Schwarzschild holes though.

There are three basic properties of a black hole:

• mass
• spin
• charge

Once these three are known, the black hole is completely specified.

This is in immense contrast to the sun for example, for which one would have to specify huge amounts of data to completely describe her.

A static black hole, that is one of no spin and no charge, is called a Schwarzschild black hole.

A black hole whose spin and/or whose charge is non-zero is a Reissner-Nordström black hole, which is our object of curiosity.

We shall not consider a hole of both charge and spin as this gives the situation an extra twist of difficulty.

The mathematics of the hole of non-zero spin to that of non-zero charge is very similar (the a2, representing the angular momentum per mass, terms would replaced by Q2, representing the charge).

However there are important differences.

1. First of all the immense electric field around a charged hole is so great that the individual atoms arriving at it would be ripped apart long before they would reach the hole, whereas this is not the case for a rotating black hole. Both have a gravitational field of equal magnitude which is powerful, but not in all cases powerful enough to annihilate ordinary matter at a distance.
2. Another difference is that with the charged hole, one can safely assume a point singularity, that is one can assume that all the matter of the hole is contained in a geometric point and that space-time has completely bent around this point, whereas with a rotating black hole one gets ring singularity, hence a spinning disk.

Since the nature of the electric field around a charged hole leaves all contemplations of inter-universal travel no fertile ground, we shall only consider a rotating black hole.