[Davea8]

It could be time to bid the Big Bang bye-bye. Cosmologists have speculated that the Universe formed from the debris ejected when a four-dimensional star collapsed into a black hole — a scenario that would help to explain why the cosmos seems to be so uniform in all directions.

The standard Big Bang model tells us that the Universe exploded out of an infinitely dense point, or singularity. But nobody knows what would have triggered this outburst: the known laws of physics cannot tell us what happened at that moment.

Can anyone clarify something for me on this? My understanding is that a "singularity" is a black hole. I don't know what a "four-dimensional star" is. But how about this: a previous universe ended it's existence as did many, many previous universes by collapsing into a singularity/black hole. And upon collapsing, the forces of heat, energy, gravity, etc. it produced caused it to explode. So there was no time between the collapse and the new Big Bang (thus ending the debate over what caused the Big Bang to happen when it did). And eventually our current universe will follow the same cyclical pattern of collapse and Big Bang once again. Cycles seem to be the norm in all nature, so why not also in the case of the Big Bang?

In fact, one Hindu belief holds this cyclical expansion/contraction to be true.

One other thing: inside a black hole all physics breaks down. The laws of physics as we know them no longer apply if I understand it right. So how do we know that the laws of mathematics hold? We are trying to understand what happened at the beginning of the universe, as well as the realities within black holes that exist . . . -using math to analyze the "realities". Suppose mathematical laws no longer apply in those cases any more than do the laws of physics?

But again, I don't see why we must "bid the Big Bang bye-bye" if the reality was a "black hole" when they are one and the same.

[BATIK]

Can anyone clarify something for me on this? My understanding is that a "singularity" is a black hole.

At the heart of a black hole lies a 'singularity.'

One other thing: inside a black hole all physics breaks down. The laws of physics as we know them no longer apply if I understand it right. So how do we know that the laws of mathematics hold? We are trying to understand what happened at the beginning of the universe, as well as the realities within black holes that exist . . . -using math to analyze the "realities". Suppose mathematical laws no longer apply in those cases any more than do the laws of physics?

Since our physical theory does indeed break down in that region, we assume there's a very small region of very exotic physics at the center of the black hole, which as mentioned is called the singularity. We're taking the irremovable mathematical singularity as a flag which indicates that new physics (involving the interface of quantum mechanics and gravity) is required in that region, which will give the singularity some physical extension and thereby avoid all the infinities and zeroes that GR on its own predicts. Attempts at calculating the conditions at the center of a black hole result in a singularity under the best available theory at the present time. That singularity might go away if we can develop a workable quantum theory of gravity.