neil wrote: A space craft could fly in and out of the event horizon of an extremely massive black hole without damage, except orbital junk has a high orbital speed close to the event horizon. The space craft would not have enough fuel to get very far outside the event horizon, probably even with a matter/anti-matter drive.
I think your point implied that you stood up for the hypothesis of that our universe is within a huge black hole.
A space craft, is different from a natural object that flies, because the craft is powered by its propulsion. So once the craft flies in the event horizon of a massive black hole, it can speed up, only if the speed > or = escape velocity of the event horizon, it can fly out of it.
However, our universe is not the space craft that is powered by its matter/antimatter engine, so once it flies into the event horizon of the huge black hole that encloses it, the universe has no way to acquire
escape velocity; it will be doomed to disappear. No proof shows that our universe is absolutely symmetrical so as to always successfully avoid mistakenly flying into the event horizon of the huge black hole since Big Bang. It is so asymmetrical that makes us think it is impossible that our universe lives in a huge black hole.