In preparing for a class on intelligent design last summer I came across a video containing a segment on fine-tuning from a friendly debate between 2020 physics Nobel Prize-winner Roger Penrose and Christian philosopher William Lane Craig. Justin Brierley is the host.

This debate segment is particularly interesting for two reasons. First, Sir Roger Penrose is himself the source for the most spectacular known example of fine-tuning, one which he estimated required a precision of one part in 10^N, where N=10¹²³. N is itself larger (far larger, as Penrose himself points out) than the number of atoms in the known universe. This “Initial Entropy Fine-Tuning” is discussed on pp. 148-151 of Stephen Meyer’s 2021 book Return of the God Hypothesis. And second, although Penrose says he is “agnostic” toward design he does not like the multiverse argument that is nearly always used to avoid the design conclusion.

Main Problem with the Multiverse

Of course, the main problem with the multiverse argument is that there is absolutely no scientific evidence — there can never be any scientific evidence — that other universes even exist. But Penrose’s reason for not appealing to the multiverse is that if that could explain fine-tuning, “we ought to be observing a much different universe than we do” (Craig’s summary of Penrose’s objection). Thus, it appears that Penrose sees the same problem with a multiverse explanation for fine-tuning that others have pointed out, and which is expressed by Michael Behe in The Edge of Evolution as follows: 

On the finite random multiverse view, we should very likely live in a bare-bones world, with little or nothing in life beyond what’s absolutely required to produce intelligent observers. So, if we find ourselves in a world lavished with extras — with much more than the minimum — we should bet heavily against our world being the result of a finite multiverse scenario….It is difficult to make a rigorous argument on such a question. Yet it seems that our world is quite lush and contains much more than what’s absolutely needed for intelligence. 

I wonder if another reason Penrose doesn’t like the multiverse argument might be that it would require an awful lot of universes to explain the fine-tuning he has discovered! In fact, if you are going to have to imagine that many universes, you might as well imagine there were enough that intelligent, conscious observers could appear fully formed by pure chance in one of them. Then there’s no need to worry about how life could have originated or evolved irreducibly complex features. (I don’t know how to calculate the probability of an intelligent, conscious observer appearing by pure chance but for context, imagine a book with as many words in it as there are atoms in the known universe. The probability of a monkey randomly typing out every word in this book correctly is much better than 1 in 10^N, where N=10¹²³ as in Penrose’s calculation above.)

The Alternative to Design

So, what does Penrose see as the alternative to design? He just pleads ignorance and says we know so little. Maybe there are other types of life, and thus other types of conscious observers that we can’t even imagine, that could evolve even in a totally different universe, and he provides a couple of examples from science fiction. 

When I first heard Penrose’s comments I thought, something is very wrong with this idea, and William Lane Craig respectfully calls it a “desperate expedient.” And the problem is not just the difficulty of imagining any form of life without stars or elements heavier than hydrogen, though that is certainly hard enough. “In the absence of fine-tuning there wouldn’t even be matter. There wouldn’t be chemistry,” says Craig. The slightest changes in almost any of the basic parameters of nature would have led to a universe without stable stars or without stars at all, without stable atoms and thus without carbon and carbon compounds or rocky planets orbiting stars, and most likely without observers! 

A Very Different Kind of Life

But even if you accept the far-fetched idea that a very different kind of life (not carbon-based, obviously), and even conscious observers, could conceivably arise in such a universe, that still does not really explain the fine-tuning we see in this universe. This video on the fine-tuning of the universe shows a world balancing on the tip of a pencil, which is balanced on the tip of a paper clip, which is balanced on …. If you saw this balancing act you would not likely think: I’m not impressed, because even if one of the supports moved slightly and this world came crashing down, it might still be possible to construct a completely different kind of world. We still need design or an incredible amount of luck to explain chemistry and stars and life as we know it.

.A seven-minute segment from the Penrose-Craig debate is embedded in the video mentioned above, beginning at the 13:55 mark.