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A Debate in California; a Piece of Business

Last Thursday, a crowd of 200 at the Village Forum in Saratoga, California, gathered to hear Dr. S. Joshua Swamidass and me speak on the topic of God and Evolution. I spoke on the evidence for design in nature that can be found in beauty, the Big Bang, fine-tuning, the DNA code, and causal circularity. I had some fun introducing elements of my own journey that had an impact on my understanding of intelligent design.

Oddly enough Dr. Swamidass spent little time talking about science. Instead he spent most of his time talking about himself, about being a Christian in science, and how his faith rests in Jesus, not science. That’s fine. I don’t know if that’s what the organizers intended. He did talk about Mount Everest being designed and human embryology being both natural and knit together by God at the same time. He presented it as if holding the two ideas in your head at the same time was enough. On embryology, I pushed back, emphasizing that there needed to be guidance for the developmental process to have come about.

The audience seemed interested and asked some good questions. My favorite was the one about dinosaurs. Why did God make them? My answer: God liked dinosaurs because he knew little boys (and not a few girls) would like them. No, seriously. Everything exists for its own sake, for its own time, and for its own reason.

For fun, in my slides I also included a closing poem, which you can see below.

A Question About a Slide

One remaining piece of business — a questioner challenged me on one of my slides, the one about the gravitational force constant. I promised to look it up. It turns out 1/10^40 is a ratio reflecting the strength of nuclear forces compared to the gravitational force, not a measurement. This massive number, 10^40,  reflects the fact that the attraction between proton and electron is much stronger than any gravitational attraction between them, for example. And if it were not so, life could not exist.

I gleaned this much from a quick scan of Paul Davies’s book The Accidental Universe. Recognizing I could use some help, I contacted a friend, Dr. Bruce Gordon, who has a degree in the philosophy of physics from Northwestern University, and who is engaged in ongoing research in the foundations of modern physics and cosmology. He kindly enlightened me more quickly than reading Paul Davies by myself would have. Bruce wrote:

The fine-tuning of Newton’s gravitational constant is relative to the strengths of the other forces, not stand alone. We certainly don’t know its [stand-alone] value to forty decimal places. The figure 10^40 comes from the fact that gravity is the weakest force and the strong nuclear force is 10^40 times stronger. These 40 orders of magnitude observationally establish a strength scale for the coupling constants of the fundamental forces.

We can now ask what would happen if the relative strengths of the forces were different. If we hold the other forces fixed and make gravity stronger or weaker, we adversely affect the universal expansion rate, star and galaxy formation, stellar lifetimes, the habitability of planets, and so on. For instance, even a ten-fold increase in the strength of gravity would have shortened the hydrogen-burning phase of the Sun to the point that the Earth would already have been vaporized as the Sun expanded into its helium-burning red giant phase.

But how much increase or decrease in the relative strength of gravity could be tolerated and the universe still be habitable in principle? A ten-thousand fold decrease in relative gravitational strength would almost inhibit galaxy, star and planetary formation to an extent that rendered life impossible, whereas an equivalent increase would reduce the lifetime of stars to less than a billion years which would not allow enough time for life to develop, and even if, per impossibile, it did, its size and complexity under the crush of gravity would prohibit it from being intelligent. So plus or minus 1/10^36 relative to the strengths of the other forces would be a more absolute figure for the fine-tuning of Newton’s gravitational constant relative to the strengths of the other forces.

As an illustration of just how precise this is, consider the fact that the observable universe is 13.7 billion years old. If we discount the expansion of space itself (which considerably increases its size), this would make the observable universe about 27.4 billion light years in diameter — say 30 billion light years for a nice round figure. Thirty billion light years is roughly 10^28 inches. If we imagine stretching a tape-measure across this distance and assigning the gravitational constant to a one-inch segment of it, then in relation to the observed forty-order-of-magnitude scale of the fundamental forces, moving the constant to the adjacent one-inch segment on either side would represent a trillionfold increase or decrease (10^12) in the strength of gravity. But the most that is permissible is 10^4/10^12 or 1/10^8 of an inch movement in either direction. In other words, if we measure the width of the observable universe in inches and regard this as representing the scale of the strengths of the physical forces, gravity is fine-tuned to such an extent that the possibility of intelligent life can only tolerate an increase or decrease in its strength of one one-hundred-millionth of an inch with respect to the diameter of the observable universe.1

A Water Molecule’s Width

That is literally awesome. That 1/10^8 inch movement is the same as 0.00000001 of an inch, or about the width of a water molecule, in either direction compared to the width of the observable universe. That is an incredible amount of very fine-tuned order — the relationship between the strong nuclear force and the gravitational force has to be that precise for stars and planets to form, and the elements that are necessary to support life. Just one water molecule’s width compared to the width of the whole universe — if the ratio were just a little too little, stars’s lives would be cut short and there would be no time for life to develop; too much and everything would expand too fast, thus preventing star and planet formation.

No wonder fine-tuning is called one of the best evidences for intelligent design. People have proposed ways around the challenge, mainly to do with the multiverse hypothesis. But there are so many other instances of fine-tuning and design perfect for creatures like us that it begins to look like a genuine plan.2


  1. Paul Davies (1982) The Accidental Universe. Cambridge: Cambridge University Press. Robin Collins (2003) “Evidence for Fine-Tuning,” in N. Manson, ed. God and Design: The Teleological Argument and Modern Science. New York: Routledge, pp. 178-199.
  2. See Michael Denton on the subject: The Wonder of Water, Children of Light, Fire-Maker, and Privileged Species.

Photos: Courtesy of The Village Forum, Saratoga, CA.