Continuing my series on truly awful internet articles on the topic of the fine-tuning of the universe for life, we turn to the work of Professor PZ Myers. Myers is a biologist at University of Minnesota Morris. He is known for his work in evolutionary biology and his outspoken opposition to the Intelligent Design movement.
On November 24, 2007, Paul Davies published an OpEd piece in the New York Times entitled “Taking Science on Faith”, discussing the commonly held but rarely discussed belief among scientists that the laws of nature are dependable, immutable, absolute, universal, and mathematical. The Edge Foundation published replies from a number of scientists. I hope to be able to discuss the wonderful, thoughtful responses of Lee Smolin and Sean Carroll soon. Here I will focus on the Myers’ reply.
In his response-to-the-responses, Davies takes Myers to task for missing the whole point of his article: “Myers goes on to attribute to me precisely the point of view I am seeking to refute”. It only gets worse when the fine-tuning of the universe is raised. Here’s Myers:
Alas, Davies also brings up the anthropic principle, that tiresome exercise in metaphysical masturbation that always flounders somewhere in the repellent ditch between narcissism and solipsism. When someone says that life would not exist if the laws of physics were just a little bit different, I have to wonder … how do they know? Just as there are many different combinations of amino acids that can make any particular enzyme, why can’t there be many different combinations of physical laws that can yield life? Do the experiment of testing different universes, then come talk to me. Until then, claiming that the anthropic principle, an undefined mish-mash of untested assumptions, supports your personal interpretation of how the universe exists and came to be is a self-delusional error.
I’m also always a bit disappointed with the statements of anthropic principle proponents for another reason. If these are the best and only laws that can give rise to intelligent life in the universe, why do they do such a lousy job of it? Life is found in one thin and delicate film on one planet in this mostly empty region of space, and even if there are other fertile planets out there, they will be nearly impossibly distant, and life will be just as fragile and prone to extinction there as here. Even on this world, all of the available environments favor bacteria over scientists or theologians, and said scientists and theologians have existed for only about 0.00001% of the lifetime of this universe.
If I wanted to argue for a position on the basis of the anthropic principle, rather than trying to pretend that we live in a Goldilocks universe, we should be wondering how we ended up in such a hostile dump of a universe, one that favors endless expanses of frigid nothingness with scattered hydrogen molecules over one that has trillions of square light years of temperate lakefront property with good fishing, soft breezes, and free wireless networking.
Myers has two main arguments, expressed as rhetorical questions:
1. How do we know that life would not exist if the laws of physics were just a little bit different?
2. How can the universe be fine-tuned for life when there is so little life in the universe, and so much of the universe is hostile to life?
My response to the first question is: because we can do theoretical physics. We don’t just measure the natural world, though this is crucial part of science. We can, with exquisite accuracy, predict the behaviour of the physical world by writing things on a sheet of paper. We propose models and explore their mathematical predictions. We find that there are parameters in these models that are not determined by the theory; they need to be measured in experiments. With these parameters in hand, the theory describes our universe beautifully. It follows that if these parameters (or the laws themselves, or the initial conditions of the universe) were different, then our universe would be different. Making theoretical predictions about these other universes is exactly the same process as making predictions about this universe. Experimental confirmation of our predictions in this universe makes us confident that the theory is correct, and thus we can predict what would happen in other universes.
Thus Myers’ claim that we cannot know what would happen if the laws of physics were different boils down to the claim that we cannot do theoretical physics. We can only “do the experiment”. This is an awfully big claim, coming from a biologist. Especially an evolutionary biologist. Will Myers demand that we “do the experiment” of creating another earth and observing it for a few billion years before he believes that all life on earth evolved from chemicals via Darwinian processes? Or is he willing to extrapolate from experimentally tested scientific theory?
Myers’ question is simply an admission of his own ignorance. How do we know? The reasons are all there in Barrow and Tipler, Hogan, Rees, Carter, Carr, Ellis et al. Has Myers carefully studied the research of these physicists and found it wanting? Myers seems to be offering nothing more than an argument from personal ignorance.
Myers asks: “Why can’t there be many different combinations of physical laws that can yield life?” This is aimed at a straw man. The claim is not that ours is the only (or best) universe that could support life, or that we are the only possible form of life. The claim is that if a universe were chosen at random from the range of possible universes, the probability of that universe being able to support intelligent life is very small. This claim is entirely consistent with the existence of other possible forms of life. To counter the claim that the universe is fine-tuned for the existence of life, Myers would need to give us some reason for believing that, given almost any set of physical constants + laws of nature + initial conditions, some form of intelligent life is able to develop.
Myers’ says that anthropic claims are “an undefined mish-mash of untested assumptions”. Let’s consider an example. If the strength of the strong force were decreased by 50%, all the atoms of all the elements used by living things would disintegrate. Undefined? It’s better than defined; it’s quantitative. This is the kind of mathematical precision that causes “physics envy” amongst biologists. Mish-mash? The sheer number and variety of fine-tuning claims are strong insurance that not all of them are wrong. Untested? Only if Myers has reason to think that we don’t understand the strong force. Assumption? No, calculation. (Masturbation? No comment.)
If Myers can imagine a form of intelligent life that could exist in such a universe, then he should tell us. We have positive reasons for believing that stable, information-carrying, replicating entities are not possible in such a universe. We know what these simple elements (H, He, Li, Be, B) can do chemically, and it’s not very much. You could (and many have) fill textbooks with all the chemical possibilities of carbon. You would struggle to fill a page on the chemistry of the first 5 elements of the periodic table. Carbon can make DNA. Beryllium couldn’t make a mess. Given the extraordinary complexity of life in this universe, it is reasonable to conclude that life is rather hard to please when it comes to universes and their laws.
Regarding question two: this is a complete non-sequitur. Suppose I claimed that in the space of possible arrangements of metal and plastic, the set of functioning automobiles is vanishingly small. There are many ways to make a car, but vastly more ways to make a pile of rubbish. Could this claim be refuted by complaining that my car doesn’t go very fast? Or that you think you could make a better car? Or that 99% of all the cars ever made no longer work? Or the possibility of aeroplanes? Myers apparently believes that a universe can only be fine-tuned if it is crammed full of life, from end to end and from start to finish.
Every criticism of this universe by Myers backfires. Life is delicate and fragile – precisely! The fragility of life supports the claim that life is very choosy about where it can form and live. If you understand why life cannot exist in frigid, dilute space, then you understand why life cannot exist in a universe in which the “lumpiness” parameter (Q) is 0.000001 (rather than 0.00001 in our universe), because in such a universe there is only frigid, dilute space. (If Q is 0.0001, you get frigid, dilute space interspersed with black holes). The same would be true if the density of the universe at the Planck time were reduced by 1 part in , or if the cosmological constant were larger by 1 part in of its natural range. Or if gravity were too weak to form matter into galaxies, stars, planets and people. Or if stars simply collapsed when they ran out of fuel (rather than exploding in supernovae), swallowing the elements they produced into neutron stars or black holes. I could go on.
Once again, Myers puts his ignorance on parade. We know why the universe is so large and dilute. John Barrow puts it quite nicely in his book “The World Within The World” (see also this article; John Wheeler makes exactly the same point in his outstanding “At Home in the Universe”):
A Universe that contained just one galaxy like our own Milky Way, with its 100 billion stars, each perhaps surrounded by planetary systems, might seem a reasonable economy if one were in the universal construction business. But such a universe, with more than a 100 billion fewer galaxies than our own, could have expanded for little more than a few months. It could have produced neither stars nor biological elements. It could contain no astronomers.
We know why it takes so long for life to appear in the universe – it takes billions of years for stars to form the necessary elements, and for these elements to collect into planets. It takes stars billions of years to form the elements because they are the energy source for life and thus need to be very stable. Paradoxical as it seems, endless expanses of frigid nothingness are necessary for a universe to be old enough for life to develop.
What does Myers want? To be at the centre of the universe? There isn’t one. To be at the centre of a galaxy? There’s a supermassive black hole there. To be at the centre of the solar system? It’s 10 million degrees in there. For the Earth to be larger? It would need to become a nuclear bomb (a star) to support itself against gravity. For the universe to be smaller, or less empty? It would collapse within a year.
Let’s allow Myers to create his “trillions of square light years of temperate lakefront property”. If he wants soft breezes then he’ll need gravity to hold his atmosphere together, to prevent it from dispersing. Gravity, in turn, will make this endless lake collapse (regardless of its size) in about = 1 day. So he’ll need to fish quickly, as he’ll be crushed into oblivion by about this time tomorrow. Unless the extreme heat generated in the collapse can counteract gravity, but that would probably boil the fish, ionise their remains and ignite the whole thing in a nuclear explosion. (Myers lakefront property is too massive for solid-state interatomic forces to support it against its own gravity. According to the virial theorem, it would be crushed into a sphere and heated to around ten million degrees Celsius.) Thank God Myers isn’t God. Perhaps Myers expects “someone” to suspend the laws of nature to preserve his utopia. Science would then be impossible, so it’s a bit odd that Myers would prefer this kind of universe, where rational inquiry isn’t rewarded with knowledge.
Let’s summarise: it is painfully, embarrassingly obvious that Myers has never seriously investigated the fine-tuning of the universe for life. When he isn’t aiming his riposte at a straw man, he’s passing judgment on whole of theoretical physics. He criticises features of our universe without which he would not exist and asks rhetorical questions that were answered long ago. Not content with merely demonstrating his ignorance, Myers proceeds to parade it as if it were a counterargument, allowing him to dismiss some of the finest physicists, astronomers, cosmologists and biologists of our time as “self-delusional”. When Myers can show that he has taken them seriously, we might just start to take him seriously.
More of my posts on fine-tuning are here.