| MadSci Network: Astronomy |
The (or at least one) difficulty with the idea of pulsars being the "other end" of black holes is that most pulsars do not have material surrounding them. There are a number of nearby pulsars (within 100 light years or so) that have been examined intensively by a number of different telescopes. (I'm thinking of B0950+08 and J0437-4715.) They show no surrounding nebulosity, as one might expect if they were the "other end" of a black hole. Even those pulsars that do show a surrounding nebulosity (the best example being the Crab pulsar of course), the nebulosity can be explained more simply as the result of a supernova explosion.
The idea of black holes having an "exit," so to speak, is somewhat fashionable among theorists of general relativity who consider wormholes. In all of the cases with which I am familiar, a wormhole would be a link between different places in our Universe. Thus, I doubt that there would be a thermodynamic problem. (I stress as well that wormholes are, at this point, an entirely theoretical construct, with no observational evidence to suggest that they exist.)
About thirty years ago it was fashionable to consider white holes as an explanation for quasars. A white hole would be the opposite of a black hole, spewing forth matter. White holes were invented to try to explain the jets emerging from powerful radio galaxies. Today a more simple explanation is favored in which the jets are powered by magnetic interactions in an accretion disk surrounding a central supermassive black hole in the galaxy.
Try the links in the MadSci Library for more information on Astronomy.
