Many physicists assume we must live in a multiverse—but their basic math may be wrong

The idea that physics seems to be optimized for life is among the most astonishing scientific findings of the last several years. This implies that a very specific range of numbers in physics has to be met in order for life to exist.

The amount of dark energy, which drives the universe's rapid expansion, is one example of fine-tuning that most physicists find puzzling. Matter would not have been able to cluster together if that force had been somewhat greater. There would have been no stars, planets, or any structure complexity if two particles had never joined, and thus no life.

That force would not have counteracted gravity if it had been much weaker. This implies that there would have been no stars, planets, or life in the cosmos if it had collapsed back on itself at the first instant of creation. The strength of dark energy has to be "just right," like Goldilocks' porridge, in order for life to be possible.

There are several such examples; this is but one.

The most widely accepted theory explaining how physics has been fine-tuned is that we are inhabitants of one universe out of many. If a sufficient number of individuals purchase lottery tickets, the likelihood increases that someone will have the winning numbers. Similarly, it becomes plausible that some universe will contain the proper numbers for life if there are enough of them, each with a distinct set of physics.

This has long struck me as the most likely explanation for fine-tuning. But the assumption from fine-tuning to a multiverse has been recognized by specialists in probability mathematics as an example of erroneous thinking, which I address in my most recent book, Why? The Universe's Intention. It specifically accuses proponents of multiverse theory of what is known as the inverse gambler's fallacy.

Imagine that one night, when Betty is the lone player in her neighborhood bingo hall, she has a phenomenal run of luck and all of her numbers come up in the first minute. "There must be a lot of people playing bingo in other bingo halls tonight," Betty muses to herself. Her logic is that it's not that unlikely that someone would get all of their numbers called out in the first minute if there are many people performing around the nation.

However, this is an example of the fallacy of the inverted gambler. It is not more probable, according to probability theory, that Betty herself would have such a run of luck, regardless of how many people are playing in other bingo rooms throughout the nation or not.

It resembles rolling dice. We incorrectly believe that our chances of getting sixes in the next throws are decreased if we string together several sixes. Furthermore, we mistakenly believe that there must have been a ton of sixes in the past if we don't receive any for a time. However, every throw actually has an identical and precise one in six chance of landing on a certain number.

Theorists of the multiverse make the same mistake. They say, "Wow, how improbable that our universe has the right numbers for life; there must be many other universes out there with the wrong numbers!" However, this is similar to Betty's belief that she may attribute her good fortune to other individuals playing bingo. Similar to a die toss, this particular universe had a specified, low probability of receiving the proper numbers when it was formed.

The "anthropic principle"—which holds that we could not have witnessed a world incompatible with life because we exist—is now raised by proponents of multiverse theory. Yet that does not rule out the existence of these other worlds.

Assume that a psychotic marksman is concealed at the rear of the bingo hall, ready to murder Betty at any time a number appears that isn't on her card. Now, the scenario is comparable to fine-tuning in the actual world: just as we could not have witnessed a cosmos with the wrong numbers for life, Betty could only have noticed the numbers needed to win.

Nevertheless, Betty would be incorrect to assume that bingo is a popular game. Similar to this, multiverse theorists' conclusions on fine-tuning to multiple worlds are incorrect.

How does the multiverse work?

But isn't there empirical proof of a multiverse? Indeed and no. Surprisingly, no one has ever examined the links between the inverse gambler's fallacy and the scientific evidence for the multiverse, as I do in my book.

The multiverse is supported by the scientific hypothesis of inflation, which holds that the early cosmos expanded enormously in size. If inflation is able to occur once, it is probably occurring in several regions of space, resulting in the creation of separate universes. There is no proof that the numbers in the many worlds' local physics differ, even if this may provide us with hints of a multiverse of some sort.

The failure of the multiverse explanation has a deeper cause. The need of entire evidence, which requires us to use the most precise evidence we have access to, is the guiding concept of probabilistic reasoning.

The most concrete proof that proponents of the multiverse have about fine-tuning is not just that "a" universe is fine-tuned, but also that "this" world is fine-tuned. It is highly improbable that our particular world, rather than any one among millions, would be fine-tuned if we accept the multiverse theory that the constants of our universe were fashioned by probabilistic processes. The hypothesis falls short of explaining the facts after we state it correctly.

According to accepted scientific theory, these numbers haven't changed since the Big Bang. If this is accurate, we have a decision to make. Either way, or it's a remarkable coincidence that the numbers in our universe match. Alternatively, the numbers reflect the way in which some unseen, innate principle drives or directs nature to produce complexity and life.

The first option seems too unlikely to be taken seriously, in my opinion. In this book, I offer a theory of the second choice, cosmic purpose, and explore how it relates to the meaning and purpose of human existence.

This is not what we anticipated from science. It is comparable to the early discoveries that the cosmos wasn't flat, beginning in the 16th century. Many people had difficulty accepting that the reality they had become accustomed to no longer explained the evidence.

I think the fine-tuning scenario we're in right now is the same. One day, we might be shocked that we spent so much time ignoring the obvious: that life exists because the cosmos is biased in favor of it.