I very much doubt the universe thinks

Recent suggestions to the contrary don’t take biology seriously, as usual

Does the universe think? Image from thinkmagazine.mt.

Sabine Hossenfelder is a brilliant theoretical physicist with whom I almost always find myself in agreement. Her book Lost in Math: How Beauty Leads Physics Astray is a superb takedown of the recent fashion in fundamental physics to judge the merits of scientific theories on the grounds of non-empirical criteria, such as “beauty” or “elegance.” Which is a really, really bad idea.

Sabine also wrote a no-nonsense rebuttal of a recent pernicious fashion in philosophy, the entirely not empirically verifiable notion of “panpsychism,” the idea that consciousness is, somehow, a basic property of matter.

Occasionally, like the rest of us, Sabine gets something wrong, or at the least she defends a questionable position. So far, I called her only on one such occasion, back in 2020, when she decided to write that predictions in science are “overrated.” This post is my second such call.

She recently published an excerpt from her book, Existential Physics: A Scientist's Guide to Life’s Biggest Questions, in the form of an essay entitled “Maybe the Universe Thinks. Hear Me Out.” I did hear her out, but I ended up not appreciating what she had to say. Let me first summarize her position as fairly as I can manage and then try to explain why I think she is off base and why it matters.

Sabine’s article is based on a technical paper by Italian astrophysicist Franco Vazza and neuroscientist Alberto Feletti, published in 2020 in Frontiers in Physics. Their basic claim is that there are structural similarities between the human brain and the universe at large, which raises the tantalizing possibility that the universe, in a sense, may think.

What does this alleged structural similarities consist of? The idea is that the 200 billion galaxies of the known universe are “connected” by intergalactic filaments of interstellar dust that make the cosmos as a whole “look like” the human connectome, i.e., the web that connects neural cells via axons in the brain of a typical Homo sapiens.

Sabine herself immediately raises a number of serious objections to the notion of a thinking universe, based on obvious disanalogies between the cosmos and the brain. First off, the universe is expanding, and the rate of expansion is increasing. This means that, even if there is some thinking going on, it has to be limited and it will get more and more difficult to sustain.