Dear Commons Community,

John Horgan, who is the author of Mind-Body Problems and My Quantum Experiment, had an article in Scientific American in 2022 and republished earlier this week sub-titled “A radical quantum hypothesis casts doubt on objective reality.”  It reviews individual perceptions and whether reality is strictly  in the eye of the beholder.  This is an old issue that has been debated ever since Max Planck and Niels Bohr first posited quantum mechanics which challenged traditional deterministic, empirical theories in the early 1900s. Horgan refers to QBism (Quantum Bayesianism Probability Theory) which Horgan defines as:

“A newish interpretation of quantum mechanics called QBism (pronounced “Cubism,” like the art movement) makes subjective experience the bedrock of knowledge and reality itself. David Mermin, a prominent theorist, says QBism can dispel the “confusion at the foundations of quantum mechanics.” You just have to accept that all knowledge begins with “individual personal experience.”

According to QBism, each of us constructs a set of beliefs about the world, based on our interactions with it. We constantly, implicitly, update our beliefs when we interact with relatives who refuse to get vaccinated or sensors tracking the swerve of an electron. The big reality in which we all live emerges from the collisions of all our subjective mini-realities.”

QBism is similar to multiple realities and  has been a bedrock for qualitative researchers for decades. I have been lecturing on this since the 1980s in my education research methods courses. In sum, this new interpretation of QBism seems like old wine in a new bottle.

Below is an excerpt from the Horgan article.

Tony

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“As philosopher Michael Strevens points out in The Knowledge Machine, science resolves disputes by means of repeated observations and experiments. Strevens calls scientists’ commitment to empirical data the “iron rule of explanation.” Ideally, the iron rule produces durable, objectively true accounts of the world.

But subjectivity is hard to expunge even in physics, the foundation on which science rests. Quantum mechanics, a mathematical model of matter at very small scales, is science’s most rigorously tested theory. Countless experiments have confirmed it, as do computer chips, lasers and other technologies that exploit quantum effects.

Unfortunately, quantum mechanics defies common sense. For more than a century, physicists have tried to interpret the theory, to turn it into a coherent story, in vain. “Every competent physicist can ‘do’ quantum mechanics,” a leading textbook says, “but the stories we tell ourselves about what we are doing are as various as the tales of Scheherazade, and almost as implausible.”

Many physicists ignore the puzzles posed by quantum mechanics. They take a practical, utilitarian attitude toward the theory, summed up by the admonition, “Shut up and calculate!” That is, forget about those quantum paradoxes and keep working on that quantum computer, which might make you rich!

Others keep probing the theory. In 1961 a prominent theorist, Eugene Wigner, proposed a thought experiment similar to the conundrum of Schrödinger’s cat. Instead of the fabled cat in a box, imagine that a friend of Wigner is inside a laboratory monitoring a radioactive specimen. When the specimen decays, a detector flashes.

Now imagine that Wigner is outside the lab. If Wigner’s friend sees the detector flash, he knows that the specimen has decayed. But to Wigner, standing outside the lab, the specimen, his friend and the entire lab hover in a blur of possible states. Wigner and his friend seem to occupy two distinct realities.

In 2020, physicists performed a version of Wigner’s thought experiment and concluded that his intuitions were correct. In a story for Science headlined “Quantum paradox points to shaky foundations of reality,” physics reporter George Musser says the experiment calls objectivity into question. “It could mean there is no such thing as an absolute fact,” Musser writes, “one that is as true for me as it is for you.”

A newish interpretation of quantum mechanics called QBism (pronounced “Cubism,” like the art movement) makes subjective experience the bedrock of knowledge and reality itself. David Mermin, a prominent theorist, says QBism can dispel the “confusion at the foundations of quantum mechanics.” You just have to accept that all knowledge begins with “individual personal experience.”

According to QBism, each of us constructs a set of beliefs about the world, based on our interactions with it. We constantly, implicitly, update our beliefs when we interact with relatives who refuse to get vaccinated or sensors tracking the swerve of an electron. The big reality in which we all live emerges from the collisions of all our subjective mini-realities.

QBists hedge their mind-centrism, if only so they don’t come across as loons or mystics. They accept that matter exists as well as mind, and they reject solipsism, which holds that no sentient being can really be sure that any other being is sentient. But QBism’s core message, science writer Amanda Gefter says, is that the idea of “a single objective reality is an illusion.” A dream, you might say.

Proponents bicker over definitions, and physicists and philosophers fond of objectivity reject QBism entirely. All this squabbling, ironically, seems to confirm QBism’s premise that there is no absolute objectivity; there are only subjective, first-person viewpoints.”

John Horgan, who has written for Scientific American since 1986, comments on science on his free online journal Cross-Check. He has also posted his books Mind-Body Problems and My Quantum Experiment online. Horgan teaches at Stevens Institute of Technology.

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