A more current view of white holes takes into consideration a revision to the standard model of the
big bang theory which states that the big bang is an explosion that happens within a black hole, with the expansion that follows the traditional interpretation of the big bang, expanding into infinite space inside the black hole. Or in other words, a miniature universe is created at the core of the black hole, which expands into extra dimensions outside of this universe.
The expansion taking place in this new miniature universe, if it could be perceived from an observer from this universe, could be looked at as a white hole. Matter that could not escape the intense gravitational pull of the black hole in this universe is instead sent speeding into the newly expanding baby universe. Using that logic, one could assume that our universe itself is a white hole. Hypothetically, this model could be used to explain the increasing rate of expansion of this universe: as matter from our parent universe is engulfed by our parent black hole (the black hole that created our universe), our own universe is fed this matter which could possibly have something to do with
dark matter and
dark energy, which currently is thought to contribute to the increase in the rate of our universe's expansion.
In addition, many argue that white holes violate the
second law of thermodynamics which states that:
"Heat cannot of itself pass from a colder to a hotter body" and "the entropy of an isolated system not at equilibrium will tend to increase over time, approaching a maximum value."
Since we are not direct observers of the other universe, some argue that it is hard to say whether or not the point of origin in the black hole would actually be colder than the newly expanding miniature universe (white hole). If the point of origin in the black hole is hotter, then matter and energy could flow towards the white hole.
Regarding the second part of the second law of thermodynamics, if we consider our universe as being directly connected to the miniature universe, then they both constitute the same isolated system. If anything, black holes by themselves without an exit point violate the second law. Black holes are points at which entropy is reversed. The entropy that exists in our solar system is greater than that of which is in a black hole, which continues to lower entropy by engulfing and trapping everything within its grasp. By including the possibility of entropy continuing to increase in a newly defined miniature universe within our own, this seems to satisfy the second law, not contradict it. This view, looks at the black hole not as an object which actually lowers entropy, but more like the opening of a narrow pipeline which appears to lower entropy from the viewpoint of someone observing the black hole and only the black hole. Using an analogy to explain this better, picture a black hole as a bath tub (analogous to the
event horizon) and a drain (analogous to the center of the black hole) in a shower. Matter is analogous to the particles of water coming down from the shower head (which could itself also be equivalent to the original feeding of our universe with matter from the initial opening of our parent black hole). As the water particles (matter) hit the tub (event horizon), they begin to merge together and exit the tub through the drain (black hole). As more and more water accumulates in the tub (if the tub is slow draining), water appears to focus its accumulation at the drain opening. This represents a lowering of entropy. The water particles are closer together and more organized at the drain opening than they are in the tub or flying through the air. To the observer looking only at the tub drain, and not knowing that the drain leads anywhere, it appears as if the drain (black hole) has reversed the entropy of the isolated system, or in other words it is acting as a collecting basin. Had the drain been extremely large, this reversal of entropy would not have appeared to have been as great. In other words, this is only a conditional reversal of entropy. The big picture is that the drain leads to a sewer (our spawned miniature universe) where the same water particles which were close together in the shower head, further apart in the air (our universe), again close together in the tub, drain and drain pipe, are now spread out even further than before and mixed in with the rest of the water in the sewer, resulting in a much larger increase in entropy of the original particles involved.
Quite a fascinating subject, so many possibilities. Btw, if you have time, check out some of the NOVA tapes/dvd's with Dr. Stephen Hawking and his view on things. He is not quite infallible, but he has a very broad insight on the subject of space/matter/black holes and the like.
