Fine tuning and many worlds
Today, I have a question for you. I posted this question on Yahoo Answers, but nobody answered it, so now it's your turn.
According to the fine tuning argument, there are a whole bunch of constants that have to have very precise values before life could exist in the universe. Some examples of these constants include the gravitational constant, the strong nuclear force, the charge of an electron, etc. There are about 26 of them, and some of them are ratios between the values of other ones. If any one of these constants were different by a smidgen, then life would not be possible. Since we live in a life-permitting universe, and since it's unimaginably unlikely that the universe would be life-permitting, it appears that the universe was rigged. Somebody intentionally tuned the values of these constants with the intention of making the universe habitable to living things.
There are a number of ways to respond to this argument. You could say the physical constants are not contingent at all, and that they could not have had any different values. There's a necessity about them. Who knows? If they could not have been otherwise, then they're not really "tuned" at all.
Or you could say we got lucky. The fine tuning argument only renders it improbable that the universe would be life-permitting. It doesn't render it impossible. Crazy things happen.
Or you could say that any sort of universe is equally improbable, but that doesn't make it at all remarkable that it would turn out some particular way. If there hadn't been life, there would've been something else that would've been unique to that universe. There's nothing special about life that makes our universe remarkable. Choosing life as the object toward which the universe was "finely tuned" is arbitrary since any combination of values for the constants would've yielded something unique. Personally, I think this is the strongest argument against the design argument from fine-tuning.
Or, you could say that if the universe had not been life-permitting, then we wouldn't be here to be thinking about it. I've heard this one a lot, but this seems to be about the worst response to the fine tuning argument. I think the firing squad analogy adequately reveals the weakness in this type of response.
But I didn't want to talk about any of these responses today. I wanted to talk about the "many worlds" or the "multiverse" response. In this response, it is granted that the constants of the universe are contingent. They could have been otherwise. And, in fact, they are otherwise in many different universe. According to this view, there may be a gazillion different universes. The more universes there are, the more likely it is that at least one of them would have the right combination of constants to be life-permitting. We just happen to live in one that is. And, in fact, every thinking thing that considers the fine tuning argument lives in such a universe.
Lemme use an analogy. Let's suppose only one person bought a lottery ticket. And let's suppose they won the lottery. If that happened, we might all be justified in thinking the game had been rigged. Somebody intentionally tweaked the balls so they would produce the same numbers that were on the ticket. But if millions of people each got a lottery ticket, it would not be remarkable at all that at least one of them would have the right numbers. And the more lottery tickets there are, the more likely it is that somebody would win.
So it is with universes. No matter how unlikely a life-permitting universe is, the more universes there are, the more likely it is that one would come along that had just the right combination of constants. That's right. The unlikely may be likely, depending on your background information.
(That reminds me of the debate about miracles, and how some people think miracles are unlikely because they're so rare and statistically improbable, and how some people respond by saying that even statistically unlikely events may be likely in light of further background information. It would be ironic if somebody thought it was absurd to suggest that anything unlikely could be likely (like the resurrection) while at the same time subscribing to the many universes idea.)
One might respond by saying there's no evidence for universes other than ours, and the explanation is ad hoc. But here, I don't think it's clear where the burden of proof lies. Both sides are positing an entity or entities to explain how it is that the universe is finely tuned for life. One side posits a designer. The other posits multiple universes. If fine-tuning alone isn't enough to justify belief in either a designer or multiple universes, and if we have to look elsewhere for verification that such entities exist, then both theories fail. Why should we presume one explanation until the other gets further verification? Why does one side have a burden of proof the other side doesn't have?
That's not really where I wanted to go, though. I'm going to get to my question now. Both sides agree about one thing--that the constants of the universe are contingent. They could've been otherwise. This question is mainly for the many worlds people. If it's true that the constants can vary in value from one universe to the next, and there's no necessity about them having any particular value, why is it that they don't vary within universes? Why, for example, don't we find some electrons in our universe that have different charges than other universes? Why isn't the force of gravity stronger with some masses than with other masses? Why is there such uniformity in our universe when it seems like there could've been diversity? Is it just an incredible coincidence that every particle of the same kind is exactly like every other particle of the same kind all over the universe, or is there a physical cause for it?