I am merely pointing out that there is no evidence of anything outside our universe. In fact near nothing about this universe is known, mathematically 85 percent of it is missing so supposedly gravity fails.
And that does not change the theory of multiverse can be possible
The big bang is a theory, it is based on observations. The multiverse is based on nothing. Sorry, that's how it is
Forgetting science fiction, one of the greatest goals of science is to discover a theory that describes the universe through a set of equations. "String theory" is quite popular, but it has a big flaw. Instead of giving a solution, these equations yield 10,500 solutions - a number so large that one would have to write a "1", followed by 500 zeros!
While this was considered the main flaw of "string theory," physicists are beginning to think that this number would represent the number of different universes that exist - each solution represents a different universe, with its own laws of the physical.
Although this idea is popular among many physicists, it is more of wishful thinking or fantasy.
In other words, no evidence or data supports the "string theory" and its supposed universes. A much more promising indicator of multiple universes is the concept of "eternal inflation".
After scientists discovered that our expanding universe is the result of a cosmic "Big Bang" - a beginning that involves a Creator - they noted the need for a brief but intense period of hyperinflation. This concept of "inflation" solves some problems, but it also suggests that instead of a single event, it could be a continuous process - in which our universe would not be the only one to "swell" After the Big Bang, but other universes might have done, or would still do, the same thing. Like soap bubbles blown by a child, our universe could be a "bubble" among all others!
Physicists and astronomers have examined the dimensions of deep space to determine if there are other hypothetical universes close to ours. But for now, they have found nothing
(New Scientist, April 6, 2013).