I thought I was done with Richard Carrier’s views on the fine-tuning of the universe for intelligent life (Part 1, Part 2). And then someone pointed me to this. It comes in response to an article by William Lane Craig. I’ve critiqued Craig’s views on fine-tuning here and here. The quotes below are from Carrier unless otherwise noted.
[H]e claims “the fundamental constants and quantities of nature must fall into an incomprehensibly narrow life-permitting range,” but that claim has been refuted–by scientists–again and again. We actually do not know that there is only a narrow life-permitting range of possible configurations of the universe. As has been pointed out to Craig by several theoretical physicists (from Krauss to Stenger), he can only get his “narrow range” by varying one single constant and holding all the others fixed, which is simply not how a universe would be randomly selected. When you allow all the constants to vary freely, the number of configurations that are life permitting actually ends up respectably high (between 1 in 8 and 1 in 4: see Victor Stenger’s The Fallacy of Fine-Tuning).
I’ve said an awful lot in response to that paragraph, so let’s just run through the highlights.
“Refuted by scientists again and again”. What, in the peer-reviewed scientific literature? I’ve published a review of the scientific literature, 200+ papers, and I can only think of a handful that oppose this conclusion, and piles and piles that support it. Here are some quotes from non-theist scientists. For example, Andrei Linde says: “The existence of an amazingly strong correlation between our own properties and the values of many parameters of our world, such as the masses and charges of electron and proton, the value of the gravitational constant, the amplitude of spontaneous symmetry breaking in the electroweak theory, the value of the vacuum energy, and the dimensionality of our world, is an experimental fact requiring an explanation.” [emphasis added.]
“By several theoretical physicists (from Krauss to Stenger)”. I’ve replied to Stenger. I had a chance to talk to Krauss briefly about fine-tuning but I’m still not sure what he thinks. His published work on anthropic matters doesn’t address the more general fine-tuning claim. Also, by saying “from” and “to”, Carrier is trying to give the impression that a great multitude stands with his claim. I’m not even sure if Krauss is with him. I’ve read loads on this subject and only Stenger defends Carrier’s point, and in a popular (ish) level book. On the other hand, Craig can cite Barrow, Carr, Carter, Davies, Deutsch, Ellis, Greene, Guth, Harrison, Hawking, Linde, Page, Penrose, Polkinghorne, Rees, Sandage, Smolin, Susskind, Tegmark, Tipler, Vilenkin, Weinberg, Wheeler, and Wilczek. (See here). With regards to the claim that “the fundamental constants and quantities of nature must fall into an incomprehensibly narrow life-permitting range”, the weight of the peer-reviewed scientific literature is overwhelmingly with Craig. (If you disagree, start citing papers).
“He can only get his “narrow range” by varying one single constant”. Wrong. The very thing that got this field started was physicists noting coincidences between a number of constants and the requirements of life. Only a handful of the 200+ scientific papers in this field vary only one variable. Read this.
“1 in 8 and 1 in 4: see Victor Stenger”. If Carrier is referring to Stenger’s program MonkeyGod, then he’s kidding himself. That “model” has 8 high school-level equations, 6 of which are wrong. It fails to understand the difference between an experimental range and a possible range, which is fatal to any discussion of fine-tuning. Assumptions are cherry-picked. Crucial constraints and constants are missing. Carrier has previously called MonkeyGod “a serious research product, defended at length in a technical article”. It was published in a philosophical journal of a humanist society, and a popular level book, and would be laughed out of any scientific journal. MonkeyGod is a bad joke.
And even those models are artificially limiting the constants that vary to the constants in our universe, when in fact there can be any number of other constants and variables.
In all the possible universes we have explored, we have found that a tiny fraction would permit the existence of intelligent life. There are other possible universes,that we haven’t explored. This is only relevant if we have some reason to believe that the trend we have observed until now will be miraculously reversed just beyond the horizon of what we have explored. In the absence of such evidence, we are justified in concluding that the possible universes we have explored are typical of all the possible universes. In fact, by beginning in our universe, known to be life-permitting, we have biased our search in favour of finding life-permitting universes.
It [is] completely impossible for any mortal to calculate the probability of a life-bearing universe from any randomly produced universe.
Nope. For a given possible universe, we specify the physics. So we know that there are no other constants and variables. A universe with other constants would be a different universe.
And we needn’t merely conjecture their innumerability: leading cosmological theories already entail, even from a single simple beginning, the formation of innumerable differently-configured regions of the universe. This is the inevitable consequence of Chaotic Inflation Theory, for example, the most popular going theory in cosmological physics today. But will Craig tell his readers that? No.
How does a historian come to think that he can crown a theory “the most popular going theory in cosmological physics today” without giving a reference? He has no authority on cosmology – no training, to expertise, no publications, and a growing pile of physics blunders.
In any case, the claim is wrong. The most popular theory in cosmological physics today is the Lambda-CDM model, the standard model of cosmology. Inflationary theory is an extension of the standard model, describing a period of accelerating expansion in the very early universe. Chaotic inflation is one of a huge number of versions of inflation (old, new, hybrid, hilltop, eternal, exponential, natural … 10 years ago Shellard could list 111 inflationary models.). A multiverse is not inevitable given inflation, and certainly not part of the standard model of cosmology. George Ellis says:
A multiverse is implied by some forms of inflation but not others. Inflation is not yet a well defined theory and chaotic inflation is just one variant of it. …the key physics involved in chaotic inflation (Coleman-de Luccia tunnelling) is extrapolated from known and tested physics to quite different regimes; that extrapolation is unverified and indeed unverifiable.
The number of different regions created by chaotic inflation is not necessarily infinite. They are not necessarily “differently-configured” either – that depends on the details of the model, in particular how the symmetries of particle physics are broken. Inflationary multiverses, as with all multiverses, must deal with the problem of Boltzmann brains – even if the multiverse exists, it may not explain fine-tuning. And most importantly, inflation itself seems to need to be fine-tuned in order to start, last, end, reheat the universe and create the right perturbations. “Although inflationary models may alleviate the “fine tuning” in the choice of initial conditions, the models themselves create new “fine tuning” issues with regard to the properties of the scalar field” (Hollands & Wald, 2002).
Most configurations of constants produce either a collapsing universe (which re-explodes, by crunch or bounce, rolling the dice all over again, so those configurations must be excluded from any randomization ratio) or a universe that accelerates its expansion until it rips apart (as its energy density approaches infinity, which results in another Big Bang, rolling the dice all over again, so those configurations must also be excluded from any randomization ratio) or a universe in between (most of which are life friendly).
You don’t “re-explode” from a big crunch. You crunch. That’s why its called a crunch. Spacetime ends. Game over. A big rip is the same – the end of space time. You don’t start over. The bounce in bouncing models is usually inserted by hand, so it is somewhat arbitrary what changes from cycle to cycle. Also, crunch vs. rip isn’t a matter of a single variable, so there is no “in between”. (Roughly, crunch depends on energy density, rip on equation of state). If by “in between”, Carrier means just “not bounce, crunch or rip” then the “most configurations” claim at the start of the quote above is vacuous. In any case, it is certainly not true that most universes “in between” are life friendly. They face the fine-tuning of their initial energy densities, inhomogeneity, entropy, cosmological constant, inflation parameters (if they inflate) etc.
For we can logically deduce the existence of innumerable universes from positing the single simplest entity imaginable at the beginning of it all: a lawless singular point of space-time with no properties other than the absence of all logically impossible states.
By what criteria is that the simplest entity imaginable? If the point is lawless, why does it evolve into something else? How does it evolve? What evolves? What defines the state space? If it is a singular point, how are there now many spacetime points? Why are they arranged in a smooth manifold? Why spacetime? What if space and time aren’t fundamental? It’s not clear that a lawless physical state makes any sense. Even if it does, if it’s lawless, why do we observe a law-like universe? If one invokes the anthropic principle and supposes that life requires a law-like environment, then you’ve got a problem, neatly explained by Paul Davies:
The many-universes theory, in its strongest form, proposes that there are no laws – just chaos. In a very tiny fraction of the universes, law-like regularities appear purely by chance – as a result of statistical freaks, such as getting heads from a coin toss a million times in a row, or dealing a perfect suit at cards. Such events, which may be so unusual as to give the appearance of a rule, are in fact just accidents that are bound to occur somewhere if you have untold zillions of trials. But if the only thing that selects the ordered universes from the chaotic ones is the existence of life, then in a universe like ours (that contains life) you would only expect to see a level of order to a degree that is just necessary for life to be maintained. Any additional order, over and above this minimal level required for life, would be exceedingly improbable, for the same reason that tossing a billion heads in a row is exceedingly less likely than merely tossing a million heads. However, there are many law-like aspects of our universe which are such that, if those laws were to fail or falter just a bit, would not constitute a threat to life. … If the law of conservation of electric charge, which is a very fundamental law of physics, should falter – if it should get a little bit wobbly, so to speak – then what would be the consequences for life of small fluctuations in the magnitude of atomic charges? Well, as far as chemistry and biology are concerned, absolutely nothing.
The problem with laws emerging from lawlessness is that we have good reason to believe that it is false. Perhaps the quote from Carrier’s article links to the writing of a professional cosmologist who will explain all these things to us! Nope. It’s another one of his blog posts.
This universe is 99.99999 percent composed of lethal radiation-filled vacuum, and 99.99999 percent of all the material in the universe comprises stars and black holes on which nothing can ever live, and 99.99999 percent of all other material in the universe (all planets, moons, clouds, asteroids) is barren of life or even outright inhospitable to life.
Fine-tuning doesn’t claim that this universe has the maximum amount of life per unit volume (or baryon, or whatever). So this argument is irrelevant. John Leslie says it well:
The issue here is not the rarity or otherwise of living beings in our universe. It is instead whether living beings could evolve in a universe just slightly different in its basic characteristics. The main evidence for multiple universes or for God is the seeming fact that tiny changes would have made our universe permanently lifeless. How curious to argue that the frozen desert of the Antarctic, the emptiness of interstellar space, and the inferno inside the stars are strong evidence against design! As if the only acceptable sign of a universe’s being God-created would be that it was crammed with living beings from end to end and from start to finish! As if God could only create a single universe so that he would need to ensure that it was well packed! (Universes).
Further, we understand why a life-permitting universe might be large and diffuse. That argument is in Barrow and Tipler’s 1986 book, so there is no excuse for not discussing it. A shortened version can be found here.
The universe we observe (including all its apparent fine tuning) has a probability of 100% if there is no god.
See my last post for an explanation of where this claim fails. In short, its a likelihood, not a posterior. Once again, Carrier manages to shed no light whatsoever on the topic at hand. He manages to accuse Craig of ignoring critics, whilst himself ignoring the entire scientific literature and any scientist who doesn’t agree with him. Which basically leaves Stenger. It seems those two were made for each other.
As I said at the end of my last post: there are some very good atheist critiques of the argument from fine-tuning out there. Read those. Avoid Carrier’s tripe.