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Wednesday, November 29, 2023

A Philosopher Considers Cosmic Fine-Tuning

The physicist Bernard Carr once declared that "if you don't want God you better have a multiverse." What he meant is that the fine-tuning of the force strengths and constants that comprise the fabric of our universe have to be calibrated with an astonishing precision or else life could not exist.

That dozens of these values should be so exquisitely fine-tuned as to permit life is such an astronomically improbable state of affairs if our universe is the only one that exists that the only way to avoid the conclusion that it was intentionally designed to be this way is to accept the idea that there are an incomprehensibly vast number of other universes beyond our own that are all different.

If that's so, then the existence of one as fine-tuned for life as is ours becomes almost inevitable, just as the odds of getting a royal flush if one is dealt enough hands of cards becomes inevitable.

Yet the multiverse hypothesis seems to be foundering, and Phillip Goff, a philosopher at Durham University, explains why in a recent article at The Conversation. Goff writes:
One of the most startling scientific discoveries of recent decades is that physics appears to be fine-tuned for life. This means that for life to be possible, certain numbers in physics had to fall within a certain, very narrow range.

One of the examples of fine-tuning which has most baffled physicists is the strength of dark energy, the force that powers the accelerating expansion of the universe. If that force had been just a little stronger, matter couldn’t clump together. No two particles would have ever combined, meaning no stars, planets, or any kind of structural complexity, and therefore no life.

If that force had been significantly weaker, it would not have counteracted gravity. This means the universe would have collapsed back on itself within the first split-second – again meaning no stars or planets or life. To allow for the possibility of life, the strength of dark energy had to be, like Goldilocks’s porridge, “just right”.

This is just one example, and there are many others.
The strength of dark energy is said to be fine-tuned to within one part in 10^123. For a point of comparison there are "only" 10^80 atoms in the entire known universe. Goff continues:
The most popular explanation for the fine-tuning of physics is that we live in one universe among a multiverse. If enough people buy lottery tickets, it becomes probable that somebody is going to have the right numbers to win. Likewise, if there are enough universes, with different numbers in their physics, it becomes likely that some universe is going to have the right numbers for life.
Goff, though formerly a believer in the multiverse, has been persuaded that the multiverse hypothesis is based on a fallacy:
Suppose Betty is the only person playing in her local bingo hall one night, and in an incredible run of luck, all of her numbers come up in the first minute.

Betty thinks to herself: “Wow, there must be lots of people playing bingo in other bingo halls tonight!” Her reasoning is: if there are lots of people playing throughout the country, then it’s not so improbable that somebody would get all their numbers called out in the first minute.

But this is an instance of the inverse gambler’s fallacy. No matter how many people are or are not playing in other bingo halls throughout the land, probability theory says it is no more likely that Betty herself would have such a run of luck.

It’s like playing dice. If we get several sixes in a row, we wrongly assume that we are less likely to get sixes in the next few throws. And if we don’t get any sixes for a while, we wrongly assume that there must have been loads of sixes in the past.

But in reality, each throw has an exact and equal probability of one in six of getting a specific number.

Multiverse theorists commit the same fallacy. They think: “Wow, how improbable that our universe has the right numbers for life; there must be many other universes out there with the wrong numbers!” But this is just like Betty thinking she can explain her run of luck in terms of other people playing bingo.

When this particular universe was created, as in a die throw, it still had a specific, low chance of getting the right numbers.

Betty would be wrong to infer that many people are playing bingo. Likewise, multiverse theorists are wrong to infer from fine-tuning to many universes.
Goff then looks at the question whether there is scientific evidence for a multiverse and also examines a hypothesis called the "anthropic principle" which is another attempt to avoid the conclusion that fine-tuning points to an intelligent creator. You can read about that peculiar argument and also why there's only very tenuous scientific evidence for a multiverse at the link.

So, does Goff accept Bernard Carr's other option, that the universe we live in was created by God. Well, no. Instead he embraces the pantheistic idea that the cosmos is itself the intelligent, purposeful agent of its own creation:
[We] face a choice. Either it’s an incredible fluke that our universe happened to have the right numbers. Or the numbers are as they are because nature is somehow driven or directed to develop complexity and life by some invisible, inbuilt principle.

In my opinion, the first option is too improbable to take seriously. My book presents a theory of the second option – cosmic purpose – and discusses its implications for human meaning and purpose.
Evidently, any theory, no matter how bizarre or lacking in evidential support, is preferable to having to accept that the universe is the creation of an intelligent, personal and transcendent God. Why?