The End of Physics?

This drawing of a train in Hoboken terminal doesn’t have anything to do with the end of physics. Or does it?

HOBOKEN, NOVEMBER 20, 2025.  Igor Pikovski, a physicist at Stevens Institute of Technology, recently asked me to talk to his department about my decades of reporting on physics. Here, more or less, is what I said in my talk, which I titled “The End of Physics?” -– John Horgan

When I became a science writer in the early 1980s, the idea that physics was approaching some sort of culmination was in the air. Stephen Hawking, in a 1981 paper titled “Is the End in Sight for Theoretical Physics?”, said physics was on the verge of discovering a theory so powerful that it would wrap up physics. This could happen soon, by 1999.

This “theory of everything” would unify quantum physics and general relativity, which are mathematically incompatible, and account for “all possible observations,” according to Hawking. This “ultimate theory” would also explain why anything exists at all, and why, out of all possible universes, we happen to live in this particular universe, which allows for our existence.

In his monster 1988 bestseller A Brief History of Time, Hawking said a unified theory might help us know “the mind of God.” That was a joke. Hawking was an atheist, who thought a final theory would eliminate the need for a divine creator.

I became a science writer in part because I wanted to report on the quest for a unified theory. Physicists were going to solve the riddle of reality! What could be more thrilling?

I covered physics for Scientific American after I became a staff writer there in 1986. I visited CERN, Fermilab and other big labs. I hung out with Hawking and other bigshots at a conference on the birth of the cosmos in 1990.

I interviewed other leaders in the quest for a final theory, including Steven Weinberg, Murray Gell-Mann and Edward Witten. Witten was said by some to be the most brilliant physicist, when it came to sheer mathematical talent, since Newton.

Witten persuaded many physicists that string theory is the best candidate for a unified theory. String theory says way, way down at the bottom of things, underlying matter and energy and even space and time, infinitesimal strings are thrumming in 10 or more dimensions.

By the time I talked to Witten in 1991, I realized that string theory and other candidates for a unified theory face a serious problem: they can’t be tested. The theories postulate things happening at the Planck scale, which is 10 to the minus 35 meters. That’s far too small to be probed by any conceivable experiment.

When I pressed Witten on string theory’s testability, or lack thereof, he said: “Good wrong ideas are extremely scarce, and good wrong ideas that even remotely rival the majesty of string theory have never been seen.” In other words, string theory is too beautiful to be wrong. In a profile of Witten for Scientific American, I called him the “Pied Piper” of string theory.

I doubled down in my criticism in my 1996 book The End of Science. The quest for a unified theory is doomed to fail, I argued, because of the testability problem. We’ll never know why there is something rather than nothing. We’ll never know why, out of all possible universes, we live in this particular universe, which allows for our existence.

We’ll probably never know exactly how life began, either, or how matter produces conscious minds. I predicted that science, in its futile attempts to solve these mysteries, will become increasingly “ironic,” meaning speculative and untestable, not to be taken too seriously. Like philosophy, literary criticism or even fiction.

Physicists denounced The End of Science. Philip Anderson coined the term “Horganism” to describe unwarranted and possibly self-fulfilling pessimism about science. I stood my ground.

In 2002 I bet physics popularizer Michio Kaku $1,000 that by 2020 no one would win a Nobel Prize for string theory or any other unified theory. When I won the bet, physicist Peter Woit posted a column with my all-time favorite headline: “Nobel Prizes announced, John Horgan wins.”

The End of Science still gets kicked around. Physicist Michael Nielsen and tech entrepreneur Patrick Collison credit me with having foreseen the current stagnation of physics. So do the renegade physicist Sabine Hossenfelder and economists charting the decline of “disruptive” science.

The irony is that over the last few years I’ve become more upbeat about the future of physics. I’ve always felt a little embarrassed for pontificating on physics when I lack formal training. (I was an English major.) So in 2020, at the beginning of the covid pandemic, I set out to learn the math that underpins quantum mechanics.

I boned up on trigonometry, logarithms and calculus, which I hadn’t studied since college, and tried to familiarize myself with linear algebra and complex numbers. I took PEP553, a course on quantum mechanics taught here at Stevens by my friend Ed Whittaker.

PEP553 crushed me, it was much too hard, but I still learned a lot. One takeaway was that the math underlying physics isn’t nearly as elegant as physics-popularizers claim.

The Schrodinger equation, for example, can give you an exact description of a hydrogen atom but not a helium atom, which is too complicated. To describe helium or anything more complex, you need ad hoc fixes and approximations.

Helium is an example of a three-body problem, which defies exact solutions. Learning about three-or-more-body problems in Ed Whittaker’s class made me even more skeptical of physicists’ claim that they can come up with a mathematical description of everything.

And yet! My Quantum Experiment, as I came to call it, made me see a way forward for physics. After reading about my project in Scientific American, a physicist named Terry Rudolph reached out to me.

Rudolph happens to be the grandson of Schrodinger. More importantly, Rudolph is the co-founder of PsiQuantum, a leader in the race to produce a commercial quantum computer. Rudolph also wrote Q Is for Quantum, which with simple arithmetic and algebra explains how quantum computing works.

After reading Rudolph’s book and talking to him, I began to think quantum computing, although egregiously hyped, might jolt physics out of its doldrums. Quantum computers could generate the positive-feedback loop between theory and experiment that propelled physics during the first half of the 20th century.

That’s my hope. Because I never wanted physics to end. I love physics, I want it to keep generating profound new insights into existence forever, even if those insights never really tell us why we’re here.

One of my favorite physicists was John Wheeler. When I interviewed Wheeler in 1991, he insisted that “we can and will understand. That's the central thing I would like to stand for. We can and will understand.”

Over the past century, physics, and especially quantum theory, have if anything made reality harder to understand. I’m reluctantly sticking to my prediction that physics, no matter how far it takes us, will never dispel the mystery of our existence. But I hope I’m wrong.

Thanks. Any questions?

Further Reading:

See the 2015 edition of The End of Science and my free online book My Quantum Experiment.