Sabine Hossenfelder, The End of Science and My Quantum Experiment

Art by Nikita Petrov

March 10, 2023. I love Sabine Hossenfelder! Even when she says I’m wrong. My favorite physicist/provocateur just posted a video, “Is science about to end?”, in which she says:

Starting in the 1970s and 1980s, a lot of physicists became very optimistic that we're pretty close to finding a theory of everything that would explain all the interactions in nature in one coherent whole. And string theory was one of the biggest candidates for this. And partly in response to this overoptimism, John Horgan wrote The End of Science, where he… argue[s] that actually, we're pretty close to the end… Horgan is not saying that we'll stop doing science or we'll stop doing research, but he's saying that there'll be no new big discoveries. We'll just add some bits and pieces to the stuff we already have.

Hossenfelder rejects my gloomy thesis, declaring that we’re not “anywhere close to the end of science.” She thinks we could be closing in on big discoveries related to quantum mechanics, which in its present formulation makes no sense. For example, the way in which physicists carry out experiments seems to determine what matter is and does. This so-called measurement problem defies the basic tenets of scientific materialism and objectivity. Hossenfelder elaborates:

I'm actually quite optimistic that we'll be able to solve the measurement problem in quantum mechanics within the next one to two decades or so, because it falls into an area--quantum technologies and quantum computing, quantum information, quantum optics--where there is a lot of technological progress at the moment. So sooner or later, they'll just stumble over something new, something that they can't explain, and then they will call for the theorists to please explain this. And this is when a lot of progress is going to happen very suddenly.

Yes, solving the measurement problem would demolish my end-of-science thesis. The measurement problem concerns the relationship between matter and mind. If we solve the measurement problem, we might at the same time solve the mind-body problem, the mystery at the bottom of all mysteries. A theory that solves the mind-body problem could justly be called a theory of everything.

I feel weirdly ambivalent about the end of science now. On the one hand, evidence of science’s decline continues to mount. See my recent post “Huge Study Confirms Science Ending! (Sort Of).” On the other hand, I sort of agree with Hossenfelder’s optimistic outlook on physics, and my change in mind is sort of her fault. Let me explain. Almost three years ago, at the start of the pandemic, Hossenfelder posted a video on quantum mechanics. She promised that in ten minutes, with a little “simple” math, she would explain the difference between superposition and entanglement. I thought, Great! These quintessential quantum concepts have always puzzled me.

But when I watched Sabine’s video, I didn’t get the math or technical terms. I felt dumb, as always when I try to grasp quantum mechanics. I felt frustrated by my lack of technical training in physics and mathematics. (My degrees are in literature and journalism.) On that same day, I decided to learn quantum mechanics, with the math. Or to try. I started calling this project “my quantum experiment.”

After reaching out to Hossenfelder and other experts for guidance, I spent the summer of 2020 studying physics textbooks (notably Leonard Susskind’s Quantum Mechanics: The Theoretical Minimum, which Hossenfelder recommended) and doing exercises in calculus and linear algebra. In the fall of 2020, I took PEP553: Quantum Mechanics and Engineering Applications, a course at Stevens Institute of Technology, the school where I teach.

In 2021, I crossed paths with Terry Rudolph. He is the grandson of Erwin Schrodinger, of the equation and cat. Rudolph is also, more importantly, a quantum-computing entrepreneur and author of the brilliant little book Q Is for Quantum. My encounter with Rudolph marked a turning point in my project. Rescuing me from a bout of gloom, when I was on the verge of abandoning my experiment, Rudolph taught me quantum mechanics by teaching me quantum computing.

Meanwhile, I filled half a dozen 8-by-11-inch notebooks with what my girlfriend calls my “scary Unabomber handwriting.” These notebooks record my thoughts, second thoughts and Nth thoughts on my studies. I recently turned these notebooks into a book, My Quantum Experiment, about the first 18 months of my project.

A page from one of my quantum notebooks. In this entry, dated February 6, 2021, I wonder whether investigations of quantum mechanics will lead to an infinite regress of “mist” (explained in Chapter Eleven of My Quantum Experiment). “EOS” stands for The End of Science.

When my experiment began, I had a few basic questions in mind: Could an oldster like me, starting more or less from scratch, learn the mathematical principles underpinning superposition and other quantum puzzles? If so, would that knowledge alter my views of quantum mechanics and related theories? Would it make me reconsider my bleak take on physics’ future? The answer to these questions turned out to be yes.

I’ve learned a lot about quantum mechanics. When I re-watch Hossenfelder’s video on superposition and entanglement now, I get it. That is, I recognize the terms she utters and even the equations she displays. She no longer loses me when she says that the wave function, symbolized by Ψ, “is a complex valued function and from its absolute square you calculate the probability of a measurement outcome.”

I can explain—and do explain in my book--how superposition and entanglement are linked. I cover other concepts: imaginary and complex numbers; matrices and vectors; limits and Euler’s identity; the three-body problem and Bayesian probability. I examine conservation of information, otherwise known as the minus first law; and the principle of least action, which I call the law of laziness. I delve into qubits, the fuzzy chunks of information that make quantum computing possible.

Hossenfelder, early in my project, predicted that someday an interpretation of quantum mechanics would be named after me. She was kidding, but I decided to take her seriously. Toward the end of My Quantum Experiment, I present my very own interpretation of quantum mechanics. I also critique other interpretations, including QBism, the many-worlds hypothesis, the pilot-wave model and Hossenfelder’s favorite, superdeterminism.

But my quantum experiment hasn’t just changed how I see quantum mechanics and physics. It has changed how I see everything, including life, death and the struggle to find meaning and happiness in a cold, cruel world. I won’t say any more here about the results of my quantum experiment, because I don’t want to give away my book’s ending.

But you can read the book now for free, because I have posted My Quantum Experiment online. Feel free to tell me what you think of it. I plan to publish comments in a “Discussion” section at the end of the book (as I did with Mind-Body Problems, which is also online). Also please alert me to technical errors. One of the joys of publishing online is that I can instantly fix mistakes. I’ll incorporate fixes into Kindle editions of My Quantum Experiment, which I plan to release soon.

If you think My Quantum Experiment is one big mistake, an abomination that should never have seen the light of day, complain to Hossenfelder. It’s really her fault.

Sabine and me in Hoboken, New Jersey, in 2018, when she gave a talk at my school.