In order to search for a good explanation for fine-tuning, we will look for three things: (1) The evidence for an explanation must not be very likely to happen in the normal course of events. Let’s say I need an explanation for why there are tiny purple handprints on the wall. Finding toddler-size prints is not very likely to happen in the normal course of everyday life since my family does not live in a painting studio. (2) The explanation must be much more probable if it is true. If my son was playing with a gallon of purple paint, is it very probable that he began “painting” on the living room wall. Why? Because the wall is the “perfect” open canvas and he is three years old. It would be very improbable if my wife pursued the same course of action. (3) The explanation must be simple, like, “My three-year-old painted on the wall.” This curbs the temptation to create elaborate explanations that are unceasingly endless and that demand further explanations—like the spontaneous appearance of an alien purple paint machine that warped through space-time from an alternate reality.
Why Fine-Tuning? Explanation #1: The Weak Anthropic Principle
Now, you may have read the entire episode thus far and wondered: “Wait a minute. We’re alive and talking about why our universe exists because we are here. So who cares if the universe is fine-tuned or not? If it wasn’t, we wouldn’t be here to discuss it. Besides, since the only thing we can observe is our universe, then who is in a position to deny that the universe is exactly as we would expect if it is all a cosmic accident?” This sentiment expresses the weak anthropic principle, which says that observers cannot exist in a universe that is unobservable. To put it another way, John Leslie uses the popular analogy of a man facing a firing squad. Fifty expert marksmen aim their guns, fire, and all the bullets miss. The man walks away unharmed. Leslie then offers two explanations. In the first, the man acknowledges that all the expert marksmen missed at the same time for whatever reason and he then shrugs his shoulder and says, “Well, if they all hadn’t missed, I wouldn’t be here to comment on what happened.” Then man then walks away. This is the weak anthropic principle. The other explanation is that something directed is happening and the man seeks answers.
Some people, including many physicists, stop at the first explanation and simply accept things the way they are. However, the fact that we can observe only a life-permitting universe does nothing to eliminate the need of an explanation for why a life-permitting universe exists. In fact, this “explanation” betrays science because if we used this approach for experiences in general—such as “The sun is high above us in the sky and that’s exactly what we should expect because that’s the way things are” or “Human beings have brains and that’s exactly what we should expect because that’s the way things are”—empiricism would not exist and it would be perfectly acceptable to never ask any critical questions. It is the height of irrationality to offer an explanation that is nothing or no explanation at all.[1] So, using our grading scale, the weak anthropic principle fails on all three measures because it does not explain anything—it only makes a declarative statement about present circumstances.
Why Fine-Tuning? Explanation #2: The Multiverse
In order to explain the presupposed fine-tuning of the universe, many physicists have proposed a model of a multiverse, which I touched upon lightly in the last episode. There, I debunked the idea of a universe coming from nothing. Cosmologically speaking, that argument still holds, but now we have more content to consider.
The multiverse idea basically says that our universe is one of a massive number of universes, and there is an antecedent process that “makes” universes. Yes, our universe is highly improbable statistically speaking, but as a function of the huge number of universes that potentially exist, we just so happen to dwell in a universe that is life-permitting. The multiverse idea has many flavors including parallel universes and daughter universes, but they essentially revolve around the same idea.
Notably, the multiverse is not a theory; rather, it is an idea derived from theoretical physics. Even those who champion the multiverse admit that the idea has not been tested nor will it be testable.[2]
To describe the multiverse, cosmologist Martin Rees uses the analogy of a clothing store with a huge selection of suits. Because of the sheer number of options, if you try on enough suits, eventually you will find one that fits. (In other words, eventually we will find ourselves in a universe that “fits” us). The problem with his analogy, of course, is that one is assumed to be in a store filled with suits designed for a person to wear. Yes, a person may come in different shapes and sizes, but you are still in a suit store with suits made by a designer and intended for a human being to put on. And, if you were willing to endure public awkwardness, you could even wear a suit that was markedly ill-fitting! Realistically, because of the demanding fine-tuning required for life, you would be far more likely to try something on that kills you because the parameters for the suit have been set to something that is life-prohibiting.
One of the grandest formulations of the multiverse concept is the “soap-bubble” idea by physicist Andre Linde.[3] Figuratively speaking, in this model, there is a large ocean of “soapy dishwater,” which represents the superspace that gives birth to new universes. Small soap bubbles blow up (or inflate) in discrete portions of the dishwater, and each new bubble represents a new universe. So, every universe in existence has a start from a “soap-bubble” in the large ocean of dishwater.
Although this may seem like an explanation on the surface, it actually creates more problems than it solves.[4] This is because the first glaring question is, “What explains the multiverse?”
The “soap-bubble” model actually raises the stakes because we now have moved from searching for an explanation for one universe (ours) to a model that presupposes the generation of a potentially infinite number of universes. Other immediate questions are obvious: “What is the mechanism that forms ‘bubbles’?” and “Where does the energy in the soapy dishwater come from?” and “How do the laws in the soapy multiverse facilitate the generation of bubbles that have different laws of physics?” and “What explains how the energy in the dishwater converts to matter in a particular bubble?”
Any mechanism—like a soapy universe-making machine—must not only select and then fine-tune the constants of physics, but it must create the laws of physics. What explains that, considering that even the best minds in the 21st century cannot explain where our laws of physics came from?[5] How does the machine choose the correct set of laws of physics, cognizant that if it neglected certain laws, life would not exist? How does the machine explain the original arrangement of matter in our universe as required by the second law of thermodynamics?[6] How does the machine explain the order observed in the whole universe as opposed to (the more likely scenario) a pocket of order just around planet Earth? Moreover, there still exists the glaring problem of multiverse fine-tuning. We already talked about many of the variables in our world that must be precisely set, some more than others. Recall that for the cosmological constant, a soapy universe-making machine would have to keep spitting out universes with unimaginable precision to get the cosmological constant just right—to one part in ten trillion trillion trillion trillion trillion trillion trillion trillion trillion trillion (10120). The soapy universe machine would have to produce a universe not only with this constant but all others in the exact narrow range in which they exist now.
Because the generation of multiple universes is far more complicated that the generation of one, this multiverse idea not only creates the demand for more explanation, it also creates a gargantuan problem from a much, much smaller one, relatively speaking.
In fact, a universe-making machine seems as if it would need to be built by an architect because it is certainly not plausible that it came from nothing, an idea already debunked in TruthFinder Episode Three. As an aside, could there be a more fundamental law—and not necessarily a multiverse—that informs the parameters of physics to have the values that they do (like an all-inclusive theory of everything)? The speculative problem here is that it upgrades the improbability of fine-tuning and demands a bigger explanation for how a fine-tuned theory of everything produces multiple fine-tuned parameters.
The multiverse idea is no more than a fantasy because no empirical proof of the multiverse exists. And, on top of that, we have to ask ourselves, “What is the multiverse?” It is something beyond and outside of the known natural universe. Which means what? That the multiverse is something supernatural. And why would anyone need a supernatural explanation for our universe? Because the universe is not simplistic and you can’t explain something that is complicated with something simplistic. Even more, no theories actualize the multiverse mathematically. To believe in the multiverse requires a healthy dose of blind faith, irrationality, and the total abandonment of logic. As Gregg Easterbrook once said, “Join the church that believes in the existence of invisible objects fifty billion galaxies wide.”[7]
The multiverse is a desperate and incomplete idea that at best, has limited explanatory power. Additionally, the idea makes so many assumptions that even if someone who had no idea what they were talking about said, “God made the universe,” that would be making far fewer assumptions and be dramatically less complicated than the multiverse.[8] We should always prefer hypotheses that we have independent evidence for or that are extrapolations from what we already know. Because there is no proof of the multiverse, this takes it out of the realm of science and into the realm of science fiction.
Ultimately, the multiverse is based on pure speculation that creates an improbable, non-verifiable, supernatural explanation that lacks an explanation for itself. As Richard Dawkins has written, “We should always be open-minded, but the only good reason to believe that something exists is if there is real evidence that it does.”[9] The multiverse idea not only makes an atheistic origin of the universe much less plausible, but it also raises the cost of holding on to that idea.
Going back to our grading scale, the multiverse idea fails because (1) there is no evidence of an explanation, (2) it is highly improbable, and (3) it is ridiculously complicated.
Why Fine-Tuning? Explanation #3: Chance
As I discussed in the last episode, chance is no thing. Chance has no causal power; it only describes probabilities when other causal forces are involved. Chance as an explanation is synonymous with ignorance, and claiming “chance” as a reason means “without cause” or “I don’t know.” Even the skeptic David Hume said it was “absurd to believe that anything could arise without a cause.”[10] Hence, chance as an explanation is not an explanation because nothing cannot produce any effects. The argument should stop there, but there is a group of the intellectually recalcitrant that clings on to the notion that highly improbable things happen all the time and thus “chance” fine-tuning remains a tenable option. As an example, consider playing poker when the dealer gives you a three-of-a-kind. There is about a 2% chance this will happen, and if you play poker long enough, you will get this hand. The example equates this unique hand with a fine-tuned universe, cognizant that the real-life chances for this “hand” are dramatically lower. But here’s the real question: So what? When you are dealt a three-of-a-kind, other than winning some poker chips, there is no special, life-giving potentiality that makes a realistic and meaningful difference. You won’t die if you get two pair, and the fact that you are being dealt cards requires a dealer and a playing deck. From a qualitative standpoint, the formation of a universe is drastically different from a card game. Ultimately, in our reality, improbable things happen because of something—not because of chance. The icing on the cake is that even if a person did entertain chance as an alternative, the probability of the perfect fine-tuning of the universe happening by chance is so small that it is statistically negligible.[11], [12]
But you don’t have to take my word for it. Mathematician Roger Penrose calculated the probability of the existence of the universe, as we know it, if it has been a random occurrence, to be a chance of one out of 10123. In probability theory, odds of less than one in 1050 equals zero probability. So, according to Penrose’s calculations, the odds of a chance existence of a fine-tuned universe is more than a trillion trillion trillion times less likely that “zero probability.” Penrose himself commented on his calculations. He said:
“This now tells how precise the Creator’s aim must have been, namely to an accuracy of one part in 10123rd power.”[13]
It’s important to realize that these odds do not refer to one improbable event. It refers to multiple improbable phenomena that must conspire to yield what is functionally impossible without a cause. Indeed, there are some that still insist the origin of the universe only had to happen once, so therefore, it could have been improbable. What this logic (or lack of logic) fails to embrace is that there is distinction between improbable and functionally impossible. All effects must have a cause, so there is no extraordinary magic in large numbers, especially when it comes to the origin of the universe.
Statistical arguments do not exist, only arguments based on real causes and effects. Hence, chance as an explanation for fine-tuning must rely on something else for its explanatory power. So, just like the weak anthropic principle, this explanation fails on all three measures because it does not explain anything.
Why Fine-Tuning? Explanation #4: Physical Necessity
This one is simple: there is no correlation between the laws of nature and all of the fine-tuning in the universe. As Paul Davies writes, “There is absolutely no evidence whatsoever the universe had to have the set of physical constants it does.”[14] A universe totally hostile to life is completely compatible with the laws of physics. Furthermore, by logical necessity, this explanation demands that it is impossible for a life-prohibiting universe to exist, which is not the case. In fact, evidence suggests the opposite: that a life-prohibiting universe is far more likely than a life-permitting one. Moreover, physical necessity suggests that the requirements of the universe were known before the universe existed and therefore by necessity, fine-tuning exists. Without an intent or design for the universe, this is highly improbable.
Using our rating scale, (1) physical necessity would be required and therefore very likely to happen in the normal course of events, (2) it is not probable because evidence demonstrates that physical necessity is false, and (3) physical necessity is indeed very simple, yet it is too simple to explain anything. Hence, physical necessity fails on two counts.
So are there any good explanations left? Yes, and that will be our focus in Part III. See you in one week.
Dr. C. H. E. Sadaphal
[1] The weak anthropic principle actually violates the first law of logic, the law of non-contradiction: a thing cannot be (an explanation) and not be at the same time and in the same relationship.
[2] Sarah Scoles, “Can Physicists Ever Prove the Multiverse is Real?” Smithsonian Magazine, April 19, 2016, accessed December 23, 2016, http://www.smithsonianmag.com/science-nature/can-physicists-ever-prove-multiverse-real-180958813/
[3] For reference, see Andre Linde, “A brief history of the multiverse,” last modified December 3, 2015, last accessed December 23, 2016, https://arxiv.org/pdf/1512.01203v1.pdf
[4] To be fair, the explanation that we are living in a highly improbable universe as a result of a soapy universe generator which has exhausted all other fine-tuning variables could in fact be true. This could explain why the universe seems to be finely tuned. This idea could explain things if we could clarify the mechanism the soapy universe generator uses and verify it. Verification would also be needed for the parameters the generator uses so that is it proven that an infinite set of universe parameters are actualized. If all this was verified, what that actually means is that the soapy universe generator is fine-tuned. And what explains that?
[5] And even if the machine did not create and worked with the laws that exist, there still remains the need for an explanation of current laws.
[6] To make this very plain, the second law of thermodynamics says that entropy increases, or that the universe is going from “orderly” to “messy.” Imagine leaving toddlers alone in a room. Very shortly, chaos will ensue. So, the problem here mandates an explanation for how a highly ordered state existed at the beginning of the universe when there is a tendency for disorder.
[7] Gregg Easterbrook, “The New Convergence,” Wired, December 1, 2002, https://www.wired.com/2002/12/convergence-3/
[8] Paul Davies, The Mind of God (New York: Simon and Schuster, 1993), 220
[9] Richard Dawkins, The Magic of Reality (New York: Free Press, 2011), 15
[10] David Hume, Letters of David Hume to William Strahan (Oxford: Oxford University Press, 2011), 1:187
[11] See Robin Collins, “A Scientific Argument for the Existence of God: The Fine-Tuning Design Argument,” in Michael J. Murray, ed., Reasons for the Hope Within (Grand Rapids, MI: Eerdmans, 1999)
[12] And yes, using our card analogy, all unique hands carry the same low probability but we are not concerned with the large number of other potential hands. We are concerned only with one hand—that is, the unique set of conditions that permit life.
[13] A probability calculated and discussed in Roger Penrose, The Emperor’s New Mind (Oxford: Oxford University Press, 1989)
[14] Paul Davies, The Mind of God (New York: Simon and Schuster, 1993)