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The universe is finely tuned for life


1997, updated 2020

Strong evidence for a Designer comes from the fine-tuning of the universal constants and the solar system, e.g.

  • The electromagnetic coupling constant binds electrons to protons in atoms. If it was smaller, fewer electrons could be held. If it was larger, electrons would be held too tightly to bond with other atoms.
  • Ratio of electron to proton mass (1:1836). Again, if this was larger or smaller, molecules could not form.
  • Carbon and oxygen nuclei have finely tuned energy levels.
  • Electromagnetic and gravitational forces are finely tuned, so the right kind of star can be stable.
  • Our sun is the right colour. If it was redder or bluer, photosynthetic response would be weaker.
  • Our sun is also the right mass. If it was larger, its brightness would change too quickly and there would be too much high energy radiation. If it was smaller, the range of planetary distances able to support life would be too narrow; the right distance would be so close to the star that tidal forces would disrupt the planet’s rotational period. UV radiation would also be inadequate for photosynthesis.
  • The earth’s distance from the sun is crucial for a stable water cycle. Too far away, and most water would freeze; too close and most water would boil.
  • The earth’s gravity, axial tilt, rotation period, magnetic field, crust thickness, oxygen/nitrogen ratio, carbon dioxide, water vapour and ozone levels are just right.

Former atheist Sir Fred Hoyle states, ‘commonsense interpretation of the facts is that a super-intelligence has monkeyed with physics, as well as chemistry and biology, and that there are no blind forces in nature.’

Objection 1: (Barrow & Tipler1) We should not be surprised that we do not observe features of the universe incompatible with our own existence, for if features were incompatible, we would not be here to notice it, so no explanation is needed.

However, as Craig pointed out (in turn borrowing from philosopher John Leslie), it does not follow that we should not be surprised that we do observe features compatible with our existence; we still need an explanation.2

By analogy, if you were dragged before a trained firing squad, and they fired and missed:

  1. You should not be surprised that you do not observe that you are dead, but
  2. You should be surprised that you do observe that you are alive.

Indeed, it really is very improbable that you should have survived, so the surprise expressed in (2) is reasonable. What would be unreasonable would be responding to “How did you survive?” with “If I didn’t, I would not be here to answer you.” No, we would want to know what happened to leave him alive (his friends bribed the squad members, loaded all their guns with blanks, or he had a deflector shield, for example); we need a real explanation!

To use another analogy, where the real question is blown off as flippantly as Hawking blows off the fine-tuning:

Parent: “Why haven’t you cleaned your room as I asked you to?”
Child: “Well, if I had cleaned it, then you wouldn’t be asking me that.”

So returning to the fine-tuning, by analogy with point (2) above, we really should be surprised to find that the constants of the universe are so fine-tuned for life, because this combination is so improbable. So we need a proper explanation.

Objection 2: All states of affairs are highly improbable, therefore every individual state of affairs is a ‘miracle’.

However, although all combinations on a combination lock are equally improbable to obtain randomly, a bank manager does not think that anyone could open the lock by chance. No-one would explain a Shakespearian sonnet by a chimp typing randomly, although any randomly typed letter sequence is equally improbable (‘I love you dearly’ surely requires more explanation than ‘asnhouyganpi;kvk klkjfl’). See also Cheating with chance.

Related to this is a claim by an atheist called Richard Carrier, who has no scientific qualifications, regarding Craig’s arguments about fine-tuning, claiming basically that we can’t know how many possible combinations of constants would be able to produce a universe with life, so we can’t perform probability calculations:

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).
However, Australian non-creationist astrophysicist Dr Luke Barnes, a specialist in fine-tuning arguments,3 refuted this as follows:
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.4

Objection 3: There are infinitely many universes.

But there is not the slightest evidence for them. In fact, no evidence is even possible, so the proposal is unscientific. Better to believe in a supernatural designer, which has good analogical support. See also Stephen Hawking and multiverses.

Carrier’s argument is basically saying: you can’t prove that your car was designed, because we don’t know how many possible arrangements of matter could produce a powered land vehicle. However, we do know that there are almost infinitely more ways that matter could be arranged that could not be a powered land vehicle.

Objection 4: This just applies to life as we know it. What about life with unknown chemistry?

However, some of the fine-tuning rules out any chemistry. There is a very narrow range of constants that permits atoms to form, and an even narrower range allows these atoms to join with others to form molecules. It’s one thing to appeal to unknown chemistry for life, but quite another to form life without molecules.5,6

References and notes

  1. Barrow, John and Tipler, Frank, The Anthropic Cosmological Principle, Clarendon Press, 1986. Return to text.
  2. William Lane Craig, Barrow and Tipler on the Anthropic Principle vs. Divine Design, 2005; Critical review of The Anthropic Cosmological Principle, International Philosophical Ouarterly 27:437–47, 1987. Return to text.
  3. Barnes, L.A., The Fine-Tuning of the Universe for Intelligent Life, arxiv.org, 2 June 2012. Return to text.
  4. Barnes, L.A., Christmas Tripe—A Fine-Tuned Critique of Richard Carrier (Part 3), Letters to Nature blogspot, 23 December 2013; bold/italics in original. Return to text.
  5. Lewis, G.F. and Barnes, L.A., A Fortunate Universe: Life in a finely tuned cosmos, Cambridge University Press, UK, 2016. Return to text.
  6. See review, Statham, D., A naturalist’s nightmare (review of A Fortunate Universe), J. Creation 32(1):48–53, April 2018; creation.com/fortunate-universe. Return to text.

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