Writing in The Spectator, Alexander Masters points out that despite the idea that scientists deal only in the world of facts, some physicists believe bizarre things that, if professed by non-scientists, would qualify as religion. Excerpts:

Physicists have a nerve. I know one (I’ll call him Mark) who berates every religious person he meets, yet honestly thinks there exist parallel universes, exactly like our own, in which we all have two noses. He refuses to give any credit to Old Testament creation myths and of course sneers at the idea of transubstantiation. But, without any sense of shame, he insists in the same breath that humans are made from the fallout of exploded stars; that it is theoretically possible for a person to decompose on one side of a black hole and recompose on the other, and that there are diamonds in the sky the size of the moon.

The Universe in Your Hand by Christophe Galfard, a young French theoretical physicist and former student of Steven Hawking, is subtitled ‘A Journey Through Space, Time and Beyond’. It could just as well have been called a journey through common sense into preposterousness. ‘A popular science book that aims to explain Quantum Mechanics, General Relativity, String Theory and Parallel Realities using storytelling instead of graphs and equations,’ declares the blurb. Since I last studied physics, as an undergraduate in the 1980s, the subject has lost all pretence of good behaviour: it is now much kookier than anything in the Bible. It took me a week to read The Universe in Your Hand and two weeks to recover from my outrage. My friend Mark’s hypocrisy is immeasurably deeper than I’d realised.

Read the whole thing. I have never quite understood why the “many-universes” theory is considered science, not religion. How could you ever falsify the thesis?

The greatest authority figure in our time and place is the Scientist. There are good reasons for that, but one gets the idea that the word of the Scientist is to the average modern person as the word of the Priest was to a medieval (caveat: that is unfair to medievals; I’m generalizing here). We assume that the Scientist must know what he’s talking about no matter what he says, because he has studied his field, and is committed to a rigorous methodology and epistemology that rules out what cannot be known empirically. If a Scientist says it, it must be true, because it has either been proven experimentally, or can be.

Again, I’m generalizing. All of us, liberals and conservatives both, have our areas in which we refuse to believe what scientists tell us. Some conservatives refuse to believe biological, paleontological and geological evidence that contradicts their religious conviction. Many conservatives refuse to believe the scientific consensus on global warming. Some liberals refuse to believe the science on vaccinations, and on genetically engineered crops. Most of us are quite selective in what we choose to believe from Science.

And you know, I think skepticism is not wrong on its face. Science is a limited form of knowledge. All forms of knowledge are. Some forms of knowledge are far more reliable ways of knowing particular things than are other forms of knowledge. Et cetera.

What Alexander Masters is railing against is a manifestation of scientism, or the belief that science is always the best way of knowing, to the exclusion of all others. Biologist Austin Hughes writes of scientism:

When I decided on a scientific career, one of the things that appealed to me about science was the modesty of its practitioners. The typical scientist seemed to be a person who knew one small corner of the natural world and knew it very well, better than most other human beings living and better even than most who had ever lived. But outside of their circumscribed areas of expertise, scientists would hesitate to express an authoritative opinion. This attitude was attractive precisely because it stood in sharp contrast to the arrogance of the philosophers of the positivist tradition, who claimed for science and its practitioners a broad authority with which many practicing scientists themselves were uncomfortable.

The temptation to overreach, however, seems increasingly indulged today in discussions about science. Both in the work of professional philosophers and in popular writings by natural scientists, it is frequently claimed that natural science does or soon will constitute the entire domain of truth. And this attitude is becoming more widespread among scientists themselves. All too many of my contemporaries in science have accepted without question the hype that suggests that an advanced degree in some area of natural science confers the ability to pontificate wisely on any and all subjects.

Hughes takes on the errors of the physicists like the one Masters reviews:

Though these arguments may do some work in evading the conclusion that our universe is fine-tuned with us in mind, they cannot sidestep, or even address, the fundamental metaphysical questions raised by the fact that something — whether one or many universes — exists rather than nothing. The main fault of these arguments lies in their failure to distinguish between necessary and contingent being. A contingent being is one that might or might not exist, and thus might or might not have certain properties. In the context of modern quantum physics, or population genetics, one might even assign probability values to the existence or non-existence of some contingent being. But a necessary being is one that must exist, and whose properties could not be other than they are.

Multiverse theorists are simply saying that our universe and its laws have merely contingent being, and that other universes are conceivable and so also may exist, albeit contingently. The idea of the contingent nature of our universe may cut against the grain of modern materialism, and so seem novel to many physicists and philosophers, but it is not in fact new. Thomas Aquinas, for example, began the third of his famous five proofs of the existence of God (a being “necessary in itself”) with the observation of contingent being (“we find among things certain ones that might or might not be”). Whether or not one is convinced by Aquinas, it should be clear that the “discovery” that our universe is a contingent event among other contingent events is perfectly consistent with his argument.

Writers like Hawking, Mlodinow, and Smolin, however, use the contingent nature of our universe and its laws to argue for a very different conclusion from that of Aquinas — namely, that some contingent universe (whether or not it turned out to be our own) must have come into being, without the existence of any necessary being. Here again probability is essential to the argument: While any universe with a particular set of laws may be very improbable, with enough universes out there it becomes highly probable. This is the same principle behind the fact that, when I toss a coin, even though there is some probability that I will get heads and some probability that I will get tails, it is certain that I will get heads or tails. Similarly, modern theorists imply, the multiverse has necessary being even though any given universe does not.

The problem with this argument is that certainty in the sense of probability is not the same thing as necessary being: If I toss a coin, it is certain that I will get heads or tails, but that outcome depends on my tossing the coin, which I may not necessarily do. Likewise, any particular universe may follow from the existence of a multiverse, but the existence of the multiverse remains to be explained. In particular, the universe-generating process assumed by some multiverse theories is itself contingent because it depends on the action of laws assumed by the theory. The latter might be called meta-laws, since they form the basis for the origin of the individual universes, each with its own individual set of laws. So what determines the meta-laws? Either we must introduce meta-meta-laws, and so on in infinite regression, or we must hold that the meta-laws themselves are necessary — and so we have in effect just changed our understanding of what the fundamental universe is to one that contains many universes. In that case, we are still left without ultimate explanations as to why that universe exists or has the characteristics it does.

When it comes to such metaphysical questions, science and scientific speculation may offer much in fleshing out details, but they have so far failed to offer any explanations that are fundamentally novel to philosophy — much less have they supplanted it entirely.

It’s a great essay; read it all.

Admittedly, I’m a sucker for physics books like the one Masters reviews, because I love thinking about these Big Ideas. But it’s also true that it would be next to impossible for me to know when a theoretical physicist is talking out of his backside, because I am not sufficiently educated in physics to know (how many people are?), and like most people, I grant a great deal of authority to scientists. And like nearly all of us, I suffer from confirmation bias.