Could there be other "big bangs" out there, and could one ever run into ours?
Before anyone jumps on me, I get that the big bang wasn't an explosion at one spot. It happened everywhere at once. And I get that space can expand faster than light without anything actually moving through space faster than light. So with that out of the way:
If eternal inflation is a thing, and different regions of space stop inflating at different times so each one ends up with its own hot dense beginning, could two of those regions ever collide? And if ours had already collided with another one, would there be anything left over that we could actually detect, or is it the kind of thing we'd never notice either way?
I'm about as far a way from an expert as can be so apologize if my framing is off.