Schrodinger’s Canary

Detecting fumes of postmodernity in the coal mine of scientific knowledge production

Quantum mechanics is the greatest and deepest scientific achievement in human history, and also one of the most intellectually volatile. Controversies about its true meaning would diffuse across the intellectual world, helping to launch the Science Wars of the 1990s, which in turn served as a trial run for the expansion of wokeness outside of academia in the 2010s.

The source of this volatility was a set of proto-postmodern ideas that got injected into the quantum program from its start, a century ago. Some of these same philosophical ideas also wound up contributing to the rise of right-wing populist movements around that time, which have flared up again in recent years. The story of modern physics, I will argue, was a kind of early warning about how such ideas can squeeze their way into a fairly rational culture and then screw it up, badly. Understanding how this happened in physics may help us deal with similar things going on across our culture today.

A number of plot lines in this story all converged, in the Summer of 1951 at the Institute for Theoretical Physics in Copenhagen, around one unsuspecting man—Paul Feyerabend, a young Austrian physicist who would go on to a career in academic philosophy that epitomizes the collapse of the pro-Enlightenment, scientific worldview. He had come to Copenhagen with a genuine desire to learn about quantum mechanics from the godfather of this research program, Niels Bohr. But what Feyerabend received from that encounter was not exactly what Bohr had intended to transmit.

To understand Niels Bohr, one must realize how different he was from the typical 20th century American physicist. Bohr had always dreamt that he would one day discover something amazing—not for what it would reveal about the natural world, as might the American, but for what it would reveal about inherent limitations on our ability to comprehend that world. He was a physicist in the European intellectual mold, with broader interests and a different agenda—an agenda in evidence well before he even got into theoretical physics.¹

What we call quantum mechanics today came about in the mid 1920s by the hands of Werner Heisenberg and Erwin Schrodinger. Bohr, true to character, immediately hailed it as a sharp break with previous scientific theories, in fact with the entire Enlightenment worldview. And he argued that this understanding of it was forced on us by a growing set of cold, hard, experimental facts. Einstein, Schrodinger, and a few others were never convinced, but most physicists eventually got on the bandwagon.

The first part of this break was doing away with the most basic idea of classical mechanics—the idea of the world being made up of particles, each one travelling along some definite trajectory in space and time. For microscopic particles like an electron, we cannot observe its whole trajectory. We can only set up a special kind of measurement device that takes a snapshot of where the electron is at a single moment in time.

Classical physics had assumed that although only a finite series of snapshots can be taken, the electron must be there—somewhere—at each moment in between. But Bohr rejects that assumption and says we have no business even talking about those theoretical, in-between positions.

We may only talk about “observables,” which represent the specific quantities—like a particle’s position at one single moment—that we could, in principle, observe when measurement is made. (Amusingly, we may also talk about this abstract thing called a “wavefunction,” but that’s because it’s viewed as just a book-keeping device to represent our knowledge about the observables in a particular experiment at a particular time.)

Bohr’s belief system was a mishmash of ideas coming out of avant-garde philosophy as of the early 1900s. Two related movements were important here: positivism and pragmatism. Logical positivism holds that science is not about discovering the fundamental nature of reality. It’s only about coming up with computational mechanisms or heuristics to predict the observable results of experiments. So scientists shouldn’t be hypothesizing objects they can’t directly observe. And this was clearly the source of that taboo on talking about unobservable particle trajectories.

Positivism itself had been intended to champion science against post-Kantian philosophy and the metaphysical castles it was building in the air. But what positivism wound up doing was to put a straightjacket on the theorist. Talking about particle trajectories became like walking into an intersectional feminism seminar and bringing up some biological male-female differences that might help to explain sociological data. Ugh. Read the room.²

Another idea in quantum mechanics called the “uncertainty principle” says that we are not allowed to talk about a particle having both a definite position and a definite velocity at the same time. This is related to the fact that there is no known way to measure both the position and the velocity at once—positivism strikes again. But there’s more.

It’s not merely about what we can know. It’s that the position and velocity of a particle cannot exist together, in reality—at least insofar as it’s comprehensible to us. You the observer have to choose which observable, position or velocity, to measure in any given moment. And that choice shapes the reality of the particle itself. This is Bohr’s principle of “complementarity,” which he viewed as the most fundamental thing in quantum mechanics.

He emphasizes that it’s not about your measurement choice having a physical effect on the particle, something you could analyze and model. It’s that the mere act of you observing it, in the way you have chosen to do so, will summon certain properties of the particle into existence and banish others. Apart from you observing it, says Bohr, the particle has no objective reality—no specific, independent nature in its own right.

The source of this stuff is again clear once you spot it. Pragmatism, as laid out by William James, was another key influence on Bohr, especially in the early 1930s as his views on the meaning of quantum mechanics solidified.³ Pragmatism also rejects the idea of science uncovering the deep nature of reality, underneath the world of appearances. But it goes even further, denying the Enlightenment concept of truth itself as a correspondence between ideas and external reality.

For the pragmatist, truth is just what’s useful to a given scientist as he tries to forecast experimental data—another flavor of the prediction-machine view of science. And thus truth is not universal. Two different scientists may have clashing perspectives, depending on their own inquiries and purposes. If both perspectives prove useful, given their cross purposes, they may both be true at once.

Measuring the position of a particle, for Bohr, would give you one perspective. Measuring the velocity would give you another clashing, but equally useful, perspective. In the realm of human reason, Bohr says there is no way for your mind to hold both of these perspectives at once.

But there is another separate realm—the quantum realm—inhabited by the real particles-in-themselves, where the position perspective and the velocity perspective can peacefully coexist. In this sense, both perspectives are true at once. It’s just that the quantum realm is not comprehensible to reason. (This was a pinch of Kantian philosophy that spices up Bohr’s larger, pragmatist framework.)

Pragmatism’s rejection of the correspondence theory of truth had already contained a kernel of subjectivism. In Bohr’s oven, that kernel burst into a bright yellow popcorn, standing out against hundreds or even thousands of years of Western thought. Thales kicked off the field of philosophy by saying there is physical stuff out there in the world. It has its own specific nature, and that’s what determines how it behaves, independent of any observer, human or divine.

Bohr was notoriously unclear and obscurantist. He would never say it plainly; he was more troll than philosopher. What physicists took away from him was something shrouded, hedged, and ambiguous. But it was big: a rejection of Thales’ foundational idea. The reality you perceive is created by you the observer. And two different observers can create two different, mutually exclusive realities.

Characteristically, Bohr denied that this was just some provisional hypothesis. He was adamant that his whole framework is “complete,” meaning there could never be any advances beyond it on these foundational issues, in ten years or in a thousand years, no matter what else we might discover. Objective reality, the classical conception of cause and effect, a rationally comprehensible universe—all that metaphysical stuff was over, for good.

And then in 1951, it was all over—for the rationale behind Bohr’s whole program. The physicist David Bohm had figured out a way to reformulate quantum mechanics, but without this subjectivist baggage. He had rediscovered an old idea of Louis de Broglie in which the wavefunction is an objective, physical thing; and the particles are also real things, separate from the wavefunction. But it’s the wavefunction that determines their precise trajectories. Bohm then took it a step further, showing how measurement events could be understood as normal physical processes, in terms of a larger wavefunction influencing additional particles that constitute the measuring device itself.

What this meant is that external reality consists of a set of physical objects, the wavefunction and the particles, that are doing their own thing, independent of you the observer. You can physically influence a particle by bumping into it with your finger or with an advanced measuring device. But there’s no summoning of things into existence by a mere act of observation; no need for any observer-created reality. It’s just a new set of physical laws describing how real stuff, out there, works.

When a pre-publication version of Bohm’s theory began to circulate in 1951, Bohr was in Copenhagen, where Paul Feyerabend observed his reaction: “It seemed that, for him, the sky was falling in… Bohr was neither dismissive, nor shaken. He was amazed.”⁴ The impossible had been done. Bohr’s substantive program was revealed as a fairytale.

But his hip rhetorical program, which had entrenched itself over the previous two decades, proved more robust. Once a whole generation of physicists had dropped that dosage of intellectual acid, the idea of getting sober seemed like a let-down and an admission of guilt. Physicists and philosophers with expertise in quantum foundations have generally acknowledged the logic and empirical adequacy of Bohm’s theory, but the Copenhageners never let up. Their line became that it was Bohm who was the philosophical provocateur, so the reasonable thing to do was just stick with the well-established Bohrian program.

As shocked as Bohr had been on first seeing Bohm’s theory, Feyerabend was even more shocked at seeing how the politics of these rival programs played out. Physicists, the most supposedly rational actors in all of science, the heirs of Newton and Einstein, met a clear refutation of their narrative with blind, ideological dogmatism. They had said the data forced us into their weird understanding of quantum mechanics. But when Bohm refuted that claim, he was effectively ostracized. Robert Oppenheimer, who had been Bohm’s own thesis advisor in grad school at Berkeley, said it openly: “if we cannot disprove Bohm, we must agree to ignore him.”⁵

Feyerabend, observing this saga, went on to take the baton from Thomas Kuhn as the leading advocate of irrationality (“epistemological anarchy,” as he called it) in the philosophy of science. Scientific paradigms don’t gradually converge toward any kind of objective truth. They just twist and turn in the winds of orthodoxy, ideology, and ultimately pure politics. There is no fundamental difference between science and things like fairytales, witchcraft, or National Socialism:

I want to defend society and its inhabitants from all ideologies, science included. All ideologies must be seen in perspective. One must not take them too seriously. One must read them like fairytales which have lots of interesting things to say but which also contain wicked lies...⁶

Even though these two ideas had started out in opposition—Feyerabend’s epistemological anarchy and Bohr’s critique of objective reality—they were both absorbed into the marrow of right-thinking intellectuals.⁷ There is no rational “scientific method.” And reality itself, as revealed by our deepest theories, is fundamentally subjective.

This then combined with a third big idea: that core scientific theories like classical mechanics, the legacy of Enlightenment thought, were liable at any moment to be exploded by revolutionary new discoveries. It had started beforehand in physics with the theory of relativity, and it extended out into all kinds of different disciplines—into the foundations of mathematics with Godel, into “modern” art, into psychology with Freud, into economics with Marx and then again with Keynes and with the collapse of Soviet socialism, and into sociology with the Frankfurt School “critical theorists.” A wrecking ball seemed to have swept down on the entire Enlightenment worldview.

The heirs of Feyerabend’s brand of postmodernism—and their cousins in new academic creations like gender theory, critical race theory, and postcolonial theory—looked at all this and thought: “OK, now it’s our turn.” Why are all the academic sinecures and badges of cultural prestige going to white male physicists and their ilk, who have already admitted they can’t produce a truly rational account of the universe? They don’t deserve these spoils any more than we do—in fact less; they’re the oppressors.

And there was no longer any self-confident, pro-Enlightenment paradigm alive within the humanities—within philosophy, or sociology, or history—to put a stop to these radicals in what became known during the 1990’s as the “Science Wars.” Rearguard actions, like Alan Sokal’s hoax paper and other attempts to defend classical rationality, were successful in some specific battles. But the wind was behind the backs of the irrationalists and subjectivists in the long run.

It is important to understand all the anti-scientific, postmodern ideas that would go on to ignite within academia and then within our culture broadly. People like Sokal and Jonathan Rauch wrote cogently about them from early on, as others like Stephen Hicks and Helen Pluckrose have done in the following decades. But it will remain mysterious how the postmodernists prevailed over the prior, pro-scientific bent of academia, unless you understand this intellectual crisis within the scientific worldview that began well before anyone knew the name of Michel Foucault.

Wokism descends from Foucault and the other French postmodernists. But, even before postmodernism, there were things like pragmatism and positivism wreaking havoc among people who appeared to be conventional scientific and philosophical thinkers within the Enlightenment tradition. And pragmatism, a proto-postmodern movement, is also a key ingredient in the stew of the contemporary right, which is just as opposed to core Enlightenment values as the woke left is.

The story of quantum foundations and its own long-running affair with pragmatism is a microcosm of how a rational, pro-science culture of experts can be coopted by an anti-Enlightenment set of ideas for the better part of a century—so far. Because this situation is still unresolved within the physics community, it doesn’t give us any template for how to solve our broader problems today. But doing an autopsy on the quantum canary—and a couple other, related cases across modern science—gives some tantalizing ideas for where to begin.

The brief sketch of this given here indicates why it’s not enough to simply trust the expert consensus, even when it comes to the hardest of sciences. Indeed a more thorough treatment of the case of quantum foundations, alongside those other cases, confirms that the experts are sometimes very wrong, sometimes very right, and a lot of other things in between.

Two broader conclusions emerge from this: that a range of quasi-postmodern ideas are at the root of our tribalistic approaches to the problem of expertise, and yet that these ideas contain some real insights that must be grappled with if we are to find a solution.

Postmodernism had looked over the actual history of science and found it wanting, in terms of rational, orderly progress. The postmodernists concluded that scientific objectivity is simply not possible. In other words, they inductively inferred the fundamental unreliability of—inductive inference.

Despite this logical misstep, what they saw wasn’t all just hallucinations. There are examples of deeply flawed reasoning able to pass for decades as legitimate science. Quantum foundations is a startling example of this. More recently there are, e.g., the replication crisis, fiascos like string theory, a host of sketchy Covid-era pronouncements, and of course an endless list of identitarian crusades.

Academia has devolved into an uncanny hybrid. There is still plenty of legitimate research carrying forward the Enlightenment tradition, but now side by side with lots of pseudo-research ranging from careerist dreck to anti-rational, woke propaganda. The burn-it-all-down tribe can point to real problems that are deep and unlikely to self-correct on our current glidepath. But the answer cannot be to repudiate expertise as such and mindlessly hack away at scientific institutions. That will only swing the pendulum more chaotically, and create more damage.

It is not a question of whether “the experts,” seen as a single unit, are right or wrong, good or evil. It’s about developing tools by which informed outsiders can assess individual scientific fields—in fact, individual research programs—without having to inspect every single technique and study.

One key part of this toolkit is about being able to spot deeper intellectual forces, like pragmatism and even outright subjectivism, that can get implanted within the core of a research program. In such cases, someone has to separate volatile elements like those from the rational, productive parts of its core. In some cases this could require a heroic intellectual leap, as with Bohm. In others it is more prosaic, just a matter of patience and intellectual honesty.

A bigger, better toolkit will make this process more scalable. It will help individuals to form their own judgements and help society in shaping institutions to identify research programs gone wild and put real checks on them.

That kind of accountability is what people need to regain a rational degree of confidence in our whole political-epistemic system. And this is the path to de-escalating culture wars—not to apply more force at jamming one set of tribal values down the other tribe’s throat, but to discover solutions for the epistemic problems that stoked this tribalism in the first place.

1. Richard Rhodes, The Making of the Atomic Bomb, Simon & Schuster, 1995, p. 61

2. James Gleick, Genius, Pantheon Books, 1993, p. 231, illustrates this with an anecdote about Bohr’s harsh reaction when Richard Feynman violated the taboo while explaining his “path integral” method to leading quantum theorists at a conference in 1948.

3. Mara Beller, Quantum Dialogue, University of Chicago Press, 1999, p. 255

4. David Peat, Infinite Potential, Basic Books, 1996, p. 129

5. Peat, p. 133

6. Paul Feyerabend, “How to Defend Society Against Science,” Radical Philosophy, Summer 1975

7. Perhaps the opposition isn’t as stark as it seemed, because Feyerabend later developed more sympathy for some of Bohr’s own views, which he thought Bohr’s followers had distorted. But he continued to criticize Bohr’s dogmatism in dismissing the mere possibility of any alternative framework like Bohm’s.