I had a realization a while back. It is not really science, but rather, it is more like religious conjecture. I wondered about what happened before the big bang. What would cause a black hole the size of the universe to explode?
We know that in the world of tiny objects like particles, that every single thing that can happen needs to be reversible. So, if light hits an atom, and an electron jumps to a higher orbit, it must also be possible for an electron to fall to a lower orbit and emit light. The light 'particle' was absorbed by the atom because it had the difference in energies between the lower and the higher electron orbit. And, the light that is produced by the reciprocal degradation of the electrons orbit is of the same color or energy that was needed to boost it.
There is only an arrow of time for collections of particles. You can see a video of an egg breaking, and know that you are viewing the video in the correct direction, because you never see eggs un-breaking. This is not the case on the particle scale. Every particle interaction can go in either direction, so you would not be able to tell if a video of a particle event is shown in the right direction.
A video of the last few bits of matter falling into a universe sized black hole would be going in the right direction, because black holes do not release matter [other than Hawking radiation]. However, once the last bit of matter had passed the event horizon, we have a different situation. While there is matter outside of the singularity, the hole has spin in reference to the matter outside. But, once there is nothing outside to compare with, the hole no longer spins or moves through space. There is a lot of matter inside the hole, but it can no longer store it's state and the arrow of time points in either direction. It is essentially a single particle, that is absolutely motionless and without spin. Even Hawking radiation would cease, because there are no atoms near the singularity to be torn apart into particles and antiparticles.
Once the hole has lost all of its personality, the arrow of time is not defined, and it is free to reverse and explode. There can not be an observer, of course, because any particle or object outside the hole would give it a proper motion and spin. The arrow of time would not be able to switch directions. there might not be any 'space' outside of the singularity during the 'interval' that it was entirely collapsed. I would use the word 'time', but time itself might not exist right 'then'. Time itself might require some matter outside of a single universe sized black hole.
Although there can be no observer, the particle that is the compressed universe explodes in both directions of times arrow. After it gets very large and cool, it may collapse again, to repeat endlessly. explode, collapse, explode, collapse... like breathing!
