I recall reading Paul Davies who reasoned multiple universe with regards to the something that has always existed, still leads to absurdities like the "Big Bang" singularity if our universe were the only one.
Basically, since physical laws themselves are changeable i.e., could be different from one universe to the next, they are contingent. Therefore these physical laws that spawn from once universe to the next beg themselves for an explanation as to why they are the way they are and not something other.
Moving beyond Davies, in a timeless multiverse (which many would like to prove), there is the metaphysical assumption that time is not foundational to a multiverse -- that time only emerges inside universes as part of the physics. This means that on the most foundational level our universe is part of a timeless, eternal ensemble of universes. And this is what gives rise to a hypothetical possibility of
an infinite number of universes.
It doesn't pass my notice, that similar attributes that I as a Theist ascribed to God, are being ascribed to a multiverse. It is also interesting that metaphysics (i.e., philosophy) is being depended upon to describe what is/isn't possible with multiverse scenarios. But, that doesn't surprise me as logic and reasoning often sets the limits for what is/isn't possible even if such can't say what is actual.
Respected physicist Lee Smolin, who argues for evolving laws,
disagrees with the metaphysical assumptions of a timeless multiverse (required for an infinite number of universes). Rather, he believes such to be untestable or falsifiable i.e., we can't really explain why our one universe is setup with the
anthropic principle, so let's posit an infinite number of universes.
Further to this unfalsifiability, I'd further add it allows for unpredictability. Why things could possibly just pop in and out of existence within our world for no apparent reason. The physical laws as we know them, are no longer within a closed system. Why, instead of saying "God did it" people can just start claiming it was the "timeless multiverse."
At least with an intelligence, such can sustain an order. On a multiverse, there is no real reason why the laws should be always upheld.
As a reference for the unfalsifiability:
- Horgan: Some leading physicists, such as Tegmark, Susskind, and Greene, espouse multiverse theories plus the anthropic principle as a kind of final framework for cosmology. Comment?
Smolin: This is a sleigh of hand by which they hope to convert an explanatory failure into an explanatory success. If we don’t understand the values the fundamental constants take in our universe, just presume our universe is a member of an infinite and unobservable ensemble of universes each with randomly chosen parameters. Our universe has the values it does because those make it hospitable to life.
There is so much wrong with this as a scientific hypothesis. As I have explained in detail in three of my books and several papers, it is hard to see how it could make any falsifiable predictions for doable experiments. Claims to the contrary are fallacious, as I and others have explained in detail. I won’t impose the details on your readers but just mention that these criticisms have not been answered.
What we have to do is to propose mechanisms by which the laws and constants may have evolved which imply falsifiable predictions by which they can be checked. I have proposed two: cosmological natural selection and the principle of precedence.
So then, on the back of Smolin, if we
haven't got an infinite number of universes, then we've still got a finite multiverse and a beginning. This just makes more noticeable Davies' reasoning based upon the contingency of laws in the universe further -- namely given their contingency then there is something more foundational to them.
I'd myself ask not simply why the laws are the way they are (or "evolved the way they are" as Smolin would say), but why these unnecessary laws exist especially given the finiteness of them all. Perhaps, just perhaps, there is something monkeying behind the scenes.
