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WillowOne's Positions

Fine-Tuning Argument

Form

As stated by Robin Collins and William Lane Craig:

  1. The constants of physics and the initial conditions of the universe fall within the narrow ranges that permit life. The cosmological constant is said to be tuned to one part in 10^120; the initial entropy, on Roger Penrose's estimate, to one part in 10^(10^123); the strong force, the electron–proton mass ratio, and the rate of expansion each sit within a sliver of their possible values.
  2. This fine-tuning is due to physical necessity, chance, or design.
  3. It is not due to physical necessity: no known theory requires the constants to take these values.
  4. It is not due to chance: the probability is too small.
  5. Therefore it is due to design.

The cosmic habitability variant drops the probability talk: the universe permits stable atoms, long-lived stars, carbon chemistry, and planets, and a universe capable of supporting such structure is better explained by intention than by accident. I treat both here, and the earlier form of the design argument under Teleological Argument - Argument from Design.

My Positions

  1. "Could have been otherwise" is not known. There is no theory of how the constants are set. They may be free parameters, or they may be fixed by a deeper theory we do not have, or they may be the only self-consistent values. Premise 3 asserts that necessity is ruled out, and the only basis for the assertion is that we have not yet found the necessity. That is the Appeal to Ignorance, and the history of physics is a history of free parameters becoming derived quantities.
  2. The probability is undefined. To say a value is improbable, one needs a distribution over the possible values. If the range is infinite, a uniform distribution over it is not a probability at all, since it cannot sum to one (the normalisability problem; McGrew, McGrew and Vestrup, 2001). If the range is finite, no one knows what it is. The large numbers in premise 1 are ratios of a life-permitting window to a range somebody chose, and the choice is what produces the number.
  3. The life-permitting window may be far wider than claimed. The apologist's examples vary one constant while holding the others fixed, which is not how parameter space works. When several are varied together, Victor Stenger's simulations and Fred Adams's 2019 survey find that stars and chemistry survive across broad ranges. Some of the famous cases (the cosmological constant) remain genuinely puzzling to physicists; most of the list does not.
  4. The trilemma is a False Dilemma. "Necessity, chance, or design" omits selection. If there are many universes with different constants (eternal inflation and the string landscape both predict this, uninvited by atheists), then observers find themselves in the ones that permit observers, and the apparent tuning is what any observer would see (Anthropic, Survivorship Bias). I do not assert the multiverse. I note that the argument needs it to be false and does not show that it is.
  5. The puddle. Douglas Adams's puddle wakes up and marvels that its hole fits it so exactly. Life is fine-tuned to the universe, which is what evolution does, and that is mistaken for the universe being fine-tuned to life. A universe with different constants would have no carbon chemistry, and perhaps something else, or nothing; we have no way to know that "life" is the thing to count.
  6. Fine-tuned for what? Almost all of the universe is vacuum at three degrees above absolute zero; almost all of its history contained no life; almost all of the matter in it is dark; the one planet we know of with life has spent most of its time without us. Lee Smolin observes that the constants are better tuned for making black holes than for making biologists. A universe designed for life would look like the one in Genesis, small and central and full. It does not.
  7. The designer needs more explaining than the tuning. A being capable of selecting the constants of a universe is at least as improbable and as "fine-tuned" as the universe, and the argument applies to it with greater force. The theist exempts God by declaring him simple or necessary (Argument from Divine Simplicity), which is Special Pleading, and leaves me with a worse explanation than the brute fact I started with (Occam's Razor - Principle of Parsimony).
  8. God does not need fine-tuning. An omnipotent being could sustain life in a universe with any constants at all, by will. Fine-tuning is therefore not predicted by theism; it is predicted, if by anything, by a designer working within constraints, or by no designer. The apologist's claim that theism "expects" the constants is made after seeing them, and would have been made about any values (Popper's Razor).
  9. Even granted, the conclusion is Deism. A tuner of constants is not the god of any scripture. It could be a committee, a simulation, a previous universe, or a physical process we have not conceived.

This is, I think, the most interesting of the design arguments, and the one where "we do not know" is the honest answer on all sides. I decline to let that ignorance be entered as evidence (Owens Tryptic of Ignorance).

Sources

  • Collins, R., "The Teleological Argument", in Craig and Moreland (eds), The Blackwell Companion to Natural Theology (2009)
  • Barnes, L., "The Fine-Tuning of the Universe for Intelligent Life", Publications of the Astronomical Society of Australia 29 (2012), the strongest scientific statement of the premise
  • McGrew, T., McGrew, L. and Vestrup, E., "Probabilities and the Fine-Tuning Argument: A Sceptical View", Mind 110 (2001)
  • Stenger, V., The Fallacy of Fine-Tuning (2011)
  • Adams, F. C., "The degree of fine-tuning in our universe – and others", Physics Reports 807 (2019)
  • Smolin, L., The Life of the Cosmos (1997)
  • Adams, D., The Salmon of Doubt (2002), for the puddle
  • Dawkins, R., The God Delusion (2006), ch. 4
  • Penrose, R., The Emperor's New Mind (1989), for the entropy figure

Also see