The more I examine the universe and the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming.-Freeman Dyson
As noted in a previous post, fine tuning is a problem that has received mainstream acceptability within the scientific community. To summarize, for complex matter like stars and carbon to exist (which, by extension, is required for us to exist), matter needs to have characteristics that are just right. If the difference between the masses of this and that particle or the strength of this and that force were slightly different the universe as we know it would not exist. I won’t go into the details here, but the Templeton Foundation funded a reader-friendly writeup on the issue.
We appear to have not only hit the jackpot, but to have hit about a half dozen jackpots simultaneously. One explanation for this is the anthropic principle, which simply states that had we not hit all those jackpots we simply wouldn’t be around to talk about it. I kind of find this an unsatisfying just-so story, and I get the sense that most physicists do too.
Ultimately, the remaining, not-mutually-exclusive options are either some kind of God calibrating the characteristics of the universe (twisting the knobs, as Dawkins puts it), or a multiverse, where there are a vast number of dead, lifeless universes, with an occasional universe with just the right characteristics for life. We would still be a fluke, but it’s a fluke that makes sense given the law of large numbers.
For me, fine tuning is one of those things that is suggestive, but not confirmatory, of divine design. While some posit that the multiverse is more scientifically respectable, at the end of the day it’s as testable as the God hypothesis, which is to say not at all. Whichever option you choose largely hinges on your priors, and, I believe, at some point on whether you are by disposition a religious believer or not, since neither can claim the high ground of empirical falsifiability.
Of course, for me personally my gut finds it more likely that, between the universe having just the precise characteristics for life, my internal subjective experience, the creation of life on this earth, and the fact that we happened to take this particular evolutionary path, the bayesian prior for there being some intentionality outweighs my sense that our existence if the result of an infinite number of monkeys typing on typewriters, even if, in theory, the latter is a technically sufficient explanation.