First, what is “the Universe”? “Uni” means one. What we observe is estimated to be about five percent of the Oneverse. About all the rest, dark matter and energy, we have no clue. We speak casually about the Universe as if we know what it is. If we only know, perhaps, about five percent of something, can we authentically say we “know” it? I don’t think so.
Most of what we read and hear about the Oneverse is speculation. It seems to some that speculation is safe because you can’t be proven wrong. All options are open. I suggest that even our speculations should have some support in observable fact, or we have converted science to guesswork. Science begins by guessing, “What if….”, and follows up by gathering data, experimenting, exploring in order to get past the speculations.
My point? We don’t know with agreement the shape of or extent of the Universe, its size or its contents. We are constantly discovering something new, or at least coming up with a new speculation
Einstein’s spacetime continuum seems to hold up, i.e., space and time being one fabric knitted together. Move position in space, you also move in time, as we know it.
There is speculation regarding multiple, even an infinite number of universes. I suggest this speculation began out of the motivation by science to attempt to put off the unavoidable confrontation with what we call God, or more acceptable to science, “The Universal Mind”.
The need for unnumbered Universes arrises out of the undeniable fact that our Universe is preciously calibrated down to multiple decimals both at the quantum and cosmic metrics, to produce life. Life is inevitable in this Universe, meaning that it is only logical to presume the Universe is filled with life of all sorts, in all stages of evolution. Again, that is speculation, but this speculation is founded upon well established facts.
The multiple universe hypothesis (not theory) claims that out of an infinite number of possibilities, we are bound to find one Universe constructed like ours designed to produce life. For me, this is not only not science, it is simply silly. There may be multiple universes, but eventually we get to the point of having to ask, “OK, what started all this?” Is not Mind an unavoidable conclusion regarding the Source of All?
There is no science to support a proposition of self-creating universes.