Either way with as little as we know about the subject there is no reason to exclude the possibility that a black hole could exist in 2 different dimensions. Who knows?

If that location happened to be a septic tank it would contain the matter until it reached a capacity whereby it could contain no more. It would then overflow or in the case of our black hole conduit, it would explode into a BB.

We have no idea what happens to the mass that is consumed by a black hole. It could be instantly transferred to an alternate universe and reside there as an infinitely tiny speck until it reaches some kind of critical mass and goes BB.

In the case of our own BB, how long had the compressed matter that was to become our universe existed and what caused it to suddenly explode if not a continuous source of additional matter that finally caused it to go boom.

Think of the black hole as a funnel with the mouth in our universe and the tail in another dimension/universe.

Theoretically there are billions of them and each galaxy has a huge BH at it’s center.

Having only learned of their existence a couple of decades ago, we can’t say much about their persistence, cosmologically speaking.

In case I somehow missed your point, my imaginative theory is that not all black holes collect sufficient mass to create a big bang. Perhaps only the galaxy center black holes. I have no theory on how long it takes. Time is always on the side of cosmic incidents.

Another thing I don’t understand is if the balloon model is correct, and space is expanding, then we are moving away from the objects at the edge of the observable universe in the other direction. We are moving away from the point where it started, when when we were “next” to these distant galaxies.

So wouldn’t those objects at 13B lt yrs only have traveled half that distance in half the time?

Since then, I’ve done little to keep up with astrophysics and cosmology other than read Sky and Telescope, and I let my subscription expire a couple of years ago.

The only specialty I’ve stayed pretty current with is positional astronomy (because of my interest in navigation and cartography). I studied that under two of the acknowledged masters in the field, George Gatewood and Heinrich Eichorn.

The field is changing fast as it is impacted by all this new data coming in from the space program, and it is pretty much in disarray. But that’s a good thing. A very good thing.

One advantage of being old is you develop a feeling for how things are progressing in a rapidly evolving field. We know a great deal more now than we did in the 60s, but we’re a lot less sure we know what it all means than we were then. Its a cliche, but it is also undeniable, the more you learn, the more you realize how little you know.

The swamp looks very different when you’re deep inside it than it did when you walked up to the edge of it.

Inflation is something new and I’m not too sure I understand it. It has to do with the early universe expanding faster than light right after the Big Bang. It is now a proposed solution to some variations and anomalies in the expansion that have been detected recently.

What makes the expansion more like your option 2) is that the rate of expansion increases with distance. Nearby galaxies are receding at slower speeds than distant galaxies. In fact, the speed of recession is a linear function of distance, and its slope is called the Hubble Constant.

Its value is constantly being updated. According to Wikipedia,

“As of 3rd Oct 2012 the Hubble Constant, as measured by NASA’s Spitzer Telescope and reported in Science Daily, is 74.3 ± 2.1 (km/s)/Mpc.”

This means that for every million parsecs of distance, the speed of expansion increases by
roughly 74 kilometers per second.

A parsec (parallax-second) is about 3.26 light years. It is a unit convenient to astronomers because it is the distance at which the radius of earth’s orbit (an Astronomical Unit) subtends an angle of 1 second of arc. The unit was useful for baseline triangulation of stellar distances, and astronomers still use it because they are incurable traditionalists.