A Universe Tuned for Life—Part 5 on John Polkinghorne

The universe is tuned for life. As a physicist, John Polkinghorne is on familiar territory when he writes about the so-called Anthropic Principle. That’s the observation that a great many characteristics of the physical universe have to be almost exactly what they are in order for life as we know it to be possible.

For example, the fine structure constant, which measures the strength of electromagnetism, can’t be even 1% larger or smaller. The cosmological constant, which has to do with the strength of gravity, must be within a tolerance of one part in 10 to the power of 120. And there are many other examples where the way the physical universe is structured “just happens” to make life possible. There doesn’t seem to be any reason that these characteristics couldn’t be slightly different. Yet slight variances—very slight variances—and the universe would be sterile.

Polkinghorne describes evolution as the “shuffling exploration of possibilities” but notes that those possibilities are highly constrained by the physical world. Evolutionists talk about random variation—“chance”—but they don’t necessarily comment on the environment of physical necessity that chance operates within. A flipped coin may land head or tails at random, but only head or tails. The structure of the coin limits the possible results. What we find in evolution is an environment that enables random variations to lead to life, to beauty, to consciousness, to Darwin the man and the great mind.

Scientists and philosophers have lots of competing ideas about the implications of “fine tuning.” Some conclude that there must be a Designer of the universe. Others say that fine tuning means nothing more than that we humans have noticed that we live in a universe that produced humans. If it were another kind of a universe we would not be here to observe it.

Polkinghorne takes a very moderate middle ground: that the fine tuning of the universe for life is  “a fact of interest calling for an explanation.”

He uses a parable from philosopher John Leslie: if a bullet hits a single fly on a big blank wall, one seeks an explanation. Pure randomness of a single bullet cannot be ruled out, but two other explanations seem more likely: either a great number of bullets were fired, or a marksman took careful aim.

Polkinghorne wants to take the parable one step farther: if the fly had a button on its back that opened up a treasure chest of unthinkable riches, we would be all the more anxious for an explanation. That is what evolution suggests: our finely tuned universe was a rifle shot producing not just microbes, but Austen and Einstein. “The evolution of conscious life seems the most significant thing that has happened in cosmic history and we are right to be intrigued by the fact that so special a universe is required for its possibility.” [Beyond Science, 88]

One way of explaining our finely tuned universe is some physicists’ speculation that an infinite number of universes exist in parallel, though inaccessible to each other. We just happen to be in the one that produced life. This explanation corresponds to the “millions of bullets” for Leslie’s fly.

Another explanation is a divine Creator, who made a universe pregnant with life. This explanation corresponds to the marksman taking careful aim.

Polkinghorne says these explanations cannot be decided scientifically. No matter how the “multiple universe” explanation gets dressed up as science, it remains a metaphysical speculation. We need to look for other sources of understanding in order to say which is the best explanation of the “fact of interest” that we human creatures are here, and that the universe seems perfectly fashioned to make us possible.


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2 Responses to “A Universe Tuned for Life—Part 5 on John Polkinghorne”

  1. JJ Says:

    You explain this so well, I will be referencing for years I am sure. The thing I find so interesting about the facts of cosmology is that they invariably lead to a grand saw-off, a sort of cosmological “tie game” between the two sides. That, to this admittedly biased believer, looks like the only kind of universe in which freedom and faith could possibly exist.

  2. Paul Vander Klay Says:

    Again, just terrific stuff and clearly presented by you. Thanks for your service. pvk

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