This is my third blog in a series on fine-tuning as evidence for God. Here are the first and second blogs, which deal with the philosophical background. Before I share the evidence I want to refute or at least rebut a few objections seen at the popular level but rarely in scholarly circles – otherwise, readers might just ignore the argument no matter what fine-tuning evidence is presented. Generally one should be wary of dismissive claims that attempt to trivialize what many intelligent physicists and philosophers think is worthy of discussion and evaluation. Even hardened skeptics admit that the fine-tuning evidence is worth evaluating. The late Christopher Hitchens answered a question concerning what is the best argument from the other side: “I think everyone of us picks the fine-tuning one as the most intriguing… you have to spend time thinking about it, working on it. It’s not a trivial [argument].” But let’s consider some popular level responses that seek to trivialize fine-tuning.
The Universe is not Adapted to Us, We’re Adapted to the Universe
This was the primary response given by atheist philosopher Peter Boghossian when I discussed fine-tuning in his recent Q&A session at UT Dallas. This response is based on a fundamental misunderstanding of the articles in the physics literature as addressed in my previous blog. The fine-tuning deals with how the physics has to be setup before life gets started so without fine-tuning there is no evolutionary way for adapting life to the universe.
Aren’t Any Set of Physical Constants Just As Likely As Any Other?
About 5 years ago I had the opportunity to engage in sort of a friendly debate with the head of the science department at the high school where my daughter and son attended. She was taking a “Theory of Knowledge” class as part of the International Baccalaureate curriculum and the instructor needed to provide an example to students of presentations of opposing viewpoints. He had heard that I was an advocate of Intelligent Design and wanted each of us to make presentations supporting our viewpoints. He is an excellent teacher and heads the science department and I was somewhat nervous to be engaging in my first public debate of this type – this was before I had read a dozen or so books on fine-tuning and taken a graduate course on Cosmology. However, the instructor gave a surprisingly weak response to the fine-tuning evidence that I had presented. He set up an analogy for the students of dealing out a set of 5 cards from a set of 10 packs of cards with different backings. The odds of dealing out any particular hand were extraordinarily low but he argued that since any set of cards was just as likely as any other set, no inference could be made that the cards were not dealt at random. This was supposed to refute a design inference because any set of constants of physics is just as likely as any other.
However, the assumption that any set of constants is just as likely as any other is the very thing that we want to know. Starting off with that as an assumption begs the question against design. As Luke Barnes articulates in this excellent podcastdealing with responses to the fine-tuning claim, suppose we’re playing poker and every time I deal I get a royal flush. If this continues to happen, you become increasingly convinced that I’m likely to be cheating. If I responded to an accusation of cheating by just saying “well any set of 5 cards is just as likely as any other so you can’t accuse me of cheating” you would be rational to reject this explanation. The question is not “how likely is any set of 5 cards?” but rather “how likely is it I’m cheating if I just dealt myself 10 straight royal flushes?” This question accounts for the possibility that I’m cheating which would almost certainly be true in this scenario. So the right question is “given the fine-tuning evidence, how likely is it that the constants were set at random?” The values for physical constants conform to a very particular pattern – that which supports life. The fact that we have so many finely-tuned constants makes it unlikely that they were all set at random (at least in the single universe scenario and I’ve already shown some of the problems/challenges in multiverse explanations.)
Another failed objection to Fine-Tuning is based on something written by Douglas Adams, the well known author of Hitchhiker’s Guide to the Galaxy (although this quote is not from that book):
“Imagine a puddle waking up one morning and thinking, ‘This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn’t it? In fact, it fits me staggeringly well, must have been made to have me in it!’”
Richard Dawkins applied this to the fine-tuning at Adams’ eulogy. There is a meaningful lesson perhaps in this analogy but it’s not applicable to the fine-tuning. In the analogy, “gradually, the puddle gets smaller and smaller” but the water still conforms the hole perfectly up to a certain height. If we discovered that any set of constants and initial conditions would permit life, then the puddle analogy would be applicable but since the universe has to be fine-tuned to support life, it’s quite disanalogous! Any configuration of dirt supports water whereas very, very few configurations of physics can support life. Some skeptical scientists who have studied the fine-tuning explicitly state this analogy “doesn’t hold water” – such as David Deutsch.
Improbable Events Happen All the Time
Yeah, but when a series of unlikely events have something in common that is predicted by a hypothesis one generally treats that as evidence for the hypothesis. There are many cases in science where inferences are made based on probabilities. Certain organisms, for example, are considered to be evolutionary descendants because it would be extremely unlikely for unrelated organisms to randomly arrive at the same DNA sequences (from a naturalistic perspective anyway). Unlikely events or states conform to a pattern predicted by the hypothesis of common descent.
In the fine-tuning case, a series of fundamental constant of physics such as various particle masses and force strengths all happen to take on values in a narrow range that permits life. These facts conform to a long-standing hypothesis that God would want to create a life-permitting universe and leave evidence that He created it and thus fine-tuning should be treated as evidence for design.
Just one Universe so Probability of Life Must be 1 out of 1
This response implies a frequentist view of probability whereas my fine-tuning argument deals with a Bayesian approach to probability which deals with epistemic probability (as a degree in belief). Refer to this article in the Stanford Encyclopedia for some issues in the finite frequentism version of probability theory – it might be useful in some contexts but there are many cases in science where we would be unable to make reasonable inferences without a more generalized approach to probability theory. For example, if scientists are reasoning about what caused the disappearance of the dinosaurs, finite frequentism is not a useful tool for analyzing this one-time event. There are also many cases in theoretical physics in which we can compute probabilities for certain events and don’t need to rely solely on past statistics. Suppose we have just created the first ever 20-sided die (an icosahedron with numbered sides). Under the finite frequentist approach, suppose we roll the die one time and obtain a 7, should we assume the probability of rolling 7’s is 1 out of 1? We can do better using theoretical physics and recognize that we have a 1/20th chance of rolling each number if the die is perfectly constructed. In engineering, we frequently assess theoretical probabilities before deciding what to build.
Consider an example from theoretical physics – we can know that universes in which the electromagnetic force is stronger than the strong nuclear force will likely be lifeless without having to find such a universe and test it for the presence of life. In such a universe there would be no stable atoms and thus no way of plausibly storing enough information to support a self-replicating system. As Luke Barnes says, analyzing fine-tuning is “not just like theoretical physics, it is theoretical physics.” He also has an excellent blog dealing with the limitations of finite frequentism.
A common objection is that the universe is not jam packed with life, therefore the universe is not-fine-tuned for life” or that “we can’t live in most parts of the universe so it’s not fine-tuned for life.” Note that these objections are very human-centric whereas in Christian theology God not humans is the most important thing in the universe. In my introductory blog, these kinds of overly narrow expectations of what God would or wouldn’t do are what I caution against. The logical approach for a skeptic would be to assess whether or not God exists in an open-minded way and then seek out more information about His attributes. A God that is not merely a human creation should differ at least slightly from human expectations. In terms of these particular objections, God may simply want to humble humans and show us how small and powerless we are compared to Him. More importantly though, these objections are irrelevant to the fine-tuning claim that I made:
“In the set of possible physical laws, parameters and initial conditions, the subset that permits rational conscious life is very small.”
Moreover, as Barnes points out – if you can understand why humans can’t live in these other parts of the universe such as the vacuum of space or near a black hole you can understand why the universe needs to be finely-tuned because without such fine-tuning the entire universe would be a near vacuum or too full of black holes for life. So in some sense these objections implicitly affirm the fine-tuning claim.
Image: Courtesy of Rachel Hainline