So there's a question there for why the values are so exactly set, or if something forces them to be the value they are.
The anthropic principle (that if the universe weren't suitable, we wouldn't be here to know) always struck me more of reasoning that we're _not_ special.
As I understand it, 'fine tuning' is simply a fact of the universe: that the fundamental constants have values that allow for the emergence of complexity, and that even slight changes to those values would lead to homogeneous and featureless universe. I don't have the physics background to demonstrate this for myself, but I believe it.
To then reason from that fact to the existence of a multiverse or the existence of God is an extra step that one need not take, but not taking either of those steps doesn't invalidate the appearance that the fundamental constants of the universe were fine tuned for the production of complexity/life.
We could just as easily say that life on earth was “tuned” to make ”intelligent life” evolve, but we don’t have any other 4 billion year test runs of earth to see what else might have evolved. In the same way we have no data at all about the phase space of other possible universes, their constants, or how their physics would play out on cosmological timescales.
It’s not that it isn’t fun to think about. It’s just that it is unscientific.
That said, I believe the chain of logic (haven't watched the PBS video yet) is simply that were these fine-tuned constants to take any other value, there wouldn't be intelligent life to observe them. If the values were to be anything outside a narrow range, they would remain unobservable by entities within that hypothetical universe, and because we are making an observation we are implicitly sampling from the distribution of observable values. It's a Bayesian metaphysical argument?
That sounds like it presumes a multiverse, but I don't think you need an infinite number of universes or a god for that to be true... that said, it does purport to explain how fine-tuning doesn't violate certain (metaphysical?) principles of science that call for "naturalness" (which a friend once told me boils down to "all unitless constants should be either 1 or 0 otherwise it's inelegant" or something): the fine structure constant is what it is because otherwise nothing would exist to observe that it was 1/139 or 42 or whatever.
I hope this is even slightly more satisfying to read than it was to write.
I'm not assuming the constants can be changed; axiomatically, they cannot, because they're fundamental constants of the universe. I'm also not assuming that some agent was around to do the tuning. In its basic form 'fine tuning' just means that if one of the values were even slightly different we wouldn't have anything like the universe we see today, including life. The values of the constants appear as if they were tuned.
It's interesting you bring up evolution, because before that theory came about intelligent design was a reasonable assumption in trying to explain how well-adapted organisms seemed to be to their environments. It was as if someone had designed them for their roles! As it turns out the theory of evolution satisfactorily explains why organisms exhibit the appearance of design.
In a similar way the fundamental constants exhibit the appearance of having been precisely set. It's hard to imagine a scientific theory getting 'behind' the constants the way evolution was able to get 'behind' the appearance of organisms...
The point is, there might be a mismatch between our model and the underlying reality. There could be an unknown deeper structure to reality which explained why those values appear to us as “fine tuned”.
Nothing says that they couldn't be changed, but then there's the question of _why_ they can't be changed. What forced them to be the values they are? Some of them appear to be free, so are they?
I will add that, from a classical theological point of view, watchmaker type arguments are considered quite weak [0].
[0] https://edwardfeser.blogspot.com/2011/03/thomism-versus-desi...
I think it's the other way around, it's because we are complex reasoning forms of life that we must observe fine tuning of physical constants, necessary for the emergence of complexity.
See: https://en.wikipedia.org/wiki/Anthropic_Bias
I also came up with my own variation of the anthropic principle:
- 1. Extend the anthropic principle beyond physical connstant. Include factors such as the goldilock zone from planetology, the symbiogenetic origin of eukaryotic cells, the presence of the moon, etc ...
- 2. Rethink the "anthropic situation" as a collection of coincidences. It doesn't directly "select for" observers, but for the right coincidences that allow them to exists.
Two paths open for us from here:
- 3.1. Either God (or whatever phenomenon can explain the presence of the right coincidences) exists and we were dealt with the right set of coincidences.
- 3.2. Or alternatively, this collection of coincidences was built up by a random sampling process. If this is the case, then we should expect this collection to contain *superfluous* coincidences that have no impact on the existence of observers. Imagine you lost the key to your house and someone cuts a key at random from a bit of metal, which luckily turns out to unlock your door. This key has more chances to feature superfluous, redundant notches, than to be an exact copy of the original key.
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This brings a counterpoint to the cognitive perspective on pattern recognition and could be used to challenge or refine our understanding of why we perceive certain phenomena as 'coincidences' (for instance why the Moon/Sun ratios are the same for both their diameters and distances to the Earth, which allows us to observe quasi-perfect eclipses). This superfluous anthropic principle, in this case, suggests that these perceived coincidences might have an actual basis in the physical properties and probabilistic events of the universe. In other words, it is because God doesn't exist that we can see 'meaningful' coincidences "hinting" at its existence (from the perspective of magical thought).
