In a previous post, Belief and Evidence, I addressed the argument made by many atheists that those who believe in God have the burden of proof. In this view, evidence must accompany belief, and belief in anything for which there is insufficient evidence is irrational. One popular example cited by proponents of this view is the satirical creation known as the “Flying Spaghetti Monster.” Proposed as a response to the demands by creationists for equal time in the classroom with evolutionary theory, the Flying Spaghetti Monster has been cited as an example of an absurd entity which no one has the right to believe in unless one has actual evidence. According to famous atheist Richard Dawkins, disbelievers are not required to submit evidence against the existence of either God or the Flying Spaghetti Monster, it is believers that have the burden of proof.

The problem with this philosophy is that it would seem to apply equally well to many physicists’ theories of the “multiverse,” and in fact many scientists have criticized multiverse theories on the grounds that there is no way to observe or test for other universes. The most extreme multiverse theories propose that every mathematically possible universe, each with its own slight variation on physical laws and constants, exists somewhere. Multiverse theory has even led to bizarre speculations about hypothetical entities such as “Boltzmann brains.” According to some scientists, it is statistically more likely for the random fluctuations of matter to create a free-floating brain than it is for billions of years of universal evolution to lead to brains in human bodies. (You may have heard of the claim that a million monkeys typing on a million typewriters will eventually produce the works of Shakespeare — the principle is similar.) This means that reincarnation could be possible or that we are actually Boltzmann brains that were randomly generated by matter and that we merely have the illusion that we have bodies and an actual past. According to physicist Leonard Susskind, “It is part of a much bigger set of questions about how to think about probabilities in an infinite universe in which everything that can occur, does occur, infinitely many times.”

If you think it is odd that respected scientists are actually discussing the possibility of floating brains spontaneously forming, well this is just one of the strange predictions that current multiverse theories tend to create. When one proposes the existence of an infinite number of possible universes based on an infinite variety of laws and constants, then anything is possible in some universe somewhere.

So is there a universe somewhere in which the laws of matter and energy are fine-tuned to support the existence of Flying Spaghetti Monsters? This would seem to be the logical outcome of the most extreme multiverse theories. I have hesitated to bring this argument up until now, because I am not a theoretical physicist and I do not understand the mathematics behind multiverse theory. However, I recently came across an article by Marcelo Gleiser, a physicist at Dartmouth College, who sarcastically asks “Do Fairies Live in the Multiverse? Discussing multiverse theories, Gleiser writes:

This brings me to the possible existence of fairies in the multiverse. The multiverse, a popular concept in modern theoretical physics, is an extension of the usual idea of the universe to encompass many possible variations. Under this view, our universe, the sum total of what’s within our “cosmic horizon” of 46 billion light years, would be one among many others. In many theories, different universes could have radically different properties, for example, electrons and protons with different masses and charges, or no electrons at all.

As in Jorge Luis Borges’ Library of Babel, which collected all possible books, the multiverse represents all that could be real if we tweaked the alphabet of nature, combining it in as many combinations as possible.

If by fairies we mean little, fabulous entities capable of flight and of magical deeds that defy what we consider reasonable in this world, then, yes, by all means, there could be fairies somewhere in the multiverse.

So, here we have a respected physicist arguing that the logical implication of existing multiverse theories, in which every possibility exists somewhere, is that fairies may well exist. Of course, Gleiser is not actually arguing that fairies exist — he is pointing out what happens when certain scientific theories propose infinite possibilities without actually being testable.

But if multiverse theories are correct, maybe the Flying Spaghetti Monster does exist out there somewhere.