i still think that there is a multiverse and alternate realities
Taking the concept of the book
Flatland, by Edwin Abbott, we could imagine a 2-dimensional world where the 2D inhabitants discover evidence of another, 3rd dimension, but they can not perceive it. From the point of view of those of us who live in a 3-dimensional world, it is easy to imagine the residents of Flatland actually exist in 3 dimensions, but only can perceive 2 dimensions. By analogy, it may be that we perceive only in 3 dimensions, even though we may exist in 4, 5, or more dimensions.
If such were the case that we perceive in only 3 dimensions, but exist in many more dimensions, then how would we view those dimensions in terms of their inclusion in the universe? Are all the multiple dimensions in which we possible exist, beyond the three or four (if you include time), part of the one same universe we perceive, or would dimensions beyond those to which we can only observe, count as another universe?
If all dimensions are included in the one universe, then perhaps the multiverse is simply a concept that feels true, but can actually be explained by adding more imperceptible dimensions to our own. Mathematically, there are no limits to the number of dimensions.
I know this is kind of weird logic that seems to skirt the issue of a true multiverse, but what would be the difference between an infinite multiverse and an infinite dimensional single universe? I am unprepared to believe that we can't prove, at least mathematically, a multiverse, but isn't a multiverse, in part, a matter of definition? What is the universe, if there are more than one? And if there are more than one how many multiverses are there? If there is only one multiverse, why isn't it the universe? Universe means the collection of all things together.
To address the subject of the study/theory in
Multiverse Predictions for Habitability: Fundamental Physics and Galactic Habitability, McCullen Sandora. We are here, observing the universe and/or the multiverse as an example of life that does exist. Whether or not the probability is lower with a complex multiverse or higher with a simple unified single universe, or vice versa, as long as the possibility is not zero, we can not reasonably state that life is so likely or unlikely as to indicate, by it's obvious existence, anything about the complexity of the universe/multiverse and it's fundamental structures. We can't observe the existence of life in our universe and say anything like, because there exists life, life is likely. We can't say, because there exists life, life is inevitable, either.
As improbable as life might be it remains possible, as evidenced by it's observed existence. Therefore, all we can say is the possibility of life in the universe is not zero. There is no extrapolation about the complexity behind the fundamental physics that we can make from our existence.
-Will
