A Universe of Bubbles

A bubble model may explain observations but gravity is required to make a bubble rise.

Or accelleration.

Or hot air!

I haven’t even commented yet!

Seems to be a lot of bubbles around DC.

Of course, when an alligator farts it will create bubbles.

Interesting idea but I don't think universe really have an outside or pressure like a bubble.

A pressure difference between "inside" and "outside" is not enough to explain why a bubble moves. We need a pressure differential/gradient for buoyancy to emerge. So, if the bubble moves, we have to explain why this gradient exists in the first place. It should be created by a force, right? Therefore, we try to remove the need of a force to explain expansion of the bubble, by assuming a force outside it.

Even if the bubble does not move, i.e. the outside pressure is spacially constant, we will have to assume temporal pressure change. This again requires an explanation.

In few words, I think that with just sweep the problem under the carpet, by delegating the cause of natural phenomena to super-natural agents (i.e. ones that lie beyond the Universe and its Laws).

Another issue I find in the logic, is that you assume that space-time exists outside the Universe in order to "give-way" to the expanding bubble. But is there any meaning for space-time to exist outside the Universe, since most probably it was created along with it? Otherwise, if there is space-time outside our Universe, then what separates it from the "outside" non-Universe world?