First, theoretical physicist Sabine Hossenfelder:
The relevant part of the argument goes like this: It’s extremely unlikely that these constants would happen to have just exactly the values that allow for our existence. Therefore, the universe as we observe it requires an explanation. And then that explanation may be god or the multiverse or whatever is your pet idea. Particle physicists use the same type of argument when they ask for a next larger particle collider. In that case, they claim it requires explanation why the mass of the Higgs boson happens to be what it is. This is called an argument from “naturalness”. I explained this in an earlier video.
What’s wrong with the argument? What’s wrong is the claim that the values of the constants of nature that we observe are unlikely. There is no way to ever quantify this probability because we will never measure a constant of nature that has a value other than the one it does have. If you want to quantify a probability you have to collect a sample of data. You could do that, for example, if you were throwing dice.Throw them often enough, and you get an empirically supported probability distribution.
But we do not have an empirically supported probability distribution for the constants of nature. And why is that. It’s because… they are constant. Saying that the only value we have ever observed is “unlikely” is a scientifically meaningless statement. We have no data, and will never have data, which allow us to quantify the probability of something we cannot observe. There’s nothing quantifiably unlikely, therefore, there’s nothing in need of explanation.
Sabine Hossenfelder, “Was the universe made for us?” at BackRe(Action) (January 16, 2021)
Now experimental physicist Rob Sheldon:
I’ve weighed in on the debate occasionally, usually siding with Sabine. We don’t have a probability distribution for these constants, and probably never will. When we invoke one, such as [commenter] Blais’ attempt to ask about the probability of a probability function, we are playing God. So bite the bullet and do it—play God.
“Why do we have such a loving God who cares about us? In the space of all probable Gods, what is the probability that we get this one?”
Now that I have phrased it that way, you can see the problem with the cosmological fine tuning argument. It assumes we have some ability to judge God. For some people that’s no problem, for others that is deeply disturbing. That’s why I side with Sabine.
But it doesn’t have to be this way.
If, and Blais makes this same point, the cosmological constants actually ARE explainable by physical processes, then they aren’t fine-tuned at all. A magnetic field in the early Big Bang can explain a half-dozen of the fine tuning constants. Then we can get on with the true business of science and consider the laws that arranged it this way, and move away from hypotheticals about fine tuning.
Does this remove the cosmological fine tuning argument from supporting ID?
Absolutely not. In Stephen Barr’s book “Modern Physics and Ancient Faith”, he argues that the symmetry behind the laws of physics needs explaining too. We never get away from explaining. The deeper we go, the more profound it gets. As in the discussion of Hindu metaphysics that the earth is supported on the backs of 4 elephants and they in turn stand on a great turtle, the question was raised “what is the turtle standing on?” and the reply was “It’s turtles all the way down”. In the same sense we physicists can say, “It’s design all the way down.”
So we reach the same conclusions, but without the shortcut about “probability distributions of cosmological constants.” Even though I agree with Sabine about the fine tuning argument, I disagree strongly with her about the significance of the design we see in the world. “It just is” is not an explanation.
Rob Sheldon is the author of Genesis: The Long Ascent and The Long Ascent, Volume II.