What Is Real?: The Unfinished Quest for the Meaning of Quantum Physics

The stories that science tells about the world filter out into the wider culture, changing the way that we look at the world around us and our place in it. The discovery that the Earth was not at the center of the universe, Darwin’s theory of evolution, the Big Bang and an expanding universe nearly 14 billion years old, containing hundreds of billions of galaxies, each containing hundreds of billions of stars—these ideas have radically altered humanity’s conception of itself.

Science, done right, works hard to respect absolutely no authority at all other than experience and empirical data. It never succeeds entirely, but it comes closer and has a better track record than any other method we apes have found for learning about the world around us.

Nonetheless, the appeal of Copenhagen makes some sense, seen in this light. Quantum physics drove much of the technological and scientific progress of the past ninety years: nuclear power, modern computers, the Internet. Quantum-driven medical imaging changed the face of health care; quantum imaging techniques at smaller scales have revolutionized biology and kicked off the entirely new field of molecular genetics. The list goes on. Make some kind of personal peace with Copenhagen, and contribute to this amazing revolution in science . . . or take quantum physics seriously, and come face-to-face with a problem that even Einstein couldn't solve. Shutting up never looked so good.

Philosophy has an image problem. Philosophers are thought to be mystics, religious figures, bullshit artists—anything divorced from reality... Why is philosophy held in such contempt by many physicists? ... one part of the answer probably lies in the split between the two major branches of modern Western philosophy, Analytic and Continental philosophy. Continental philosophers tend to be much more suspicious of scientific claims about knowledge and truth than are their analytic colleagues. Yet the distinction between the two kinds of philosophy is not apparent from a distance—most scientists have never heard of the analytic-Continental divide. So, given that most of the highly visible philosophers in the public sphere today are Continental, and given the attitude that some (not all) Continental philosophers have toward science, it’s not terribly surprising that scientists often have disdain for all philosophers, and sometimes even think that they can do philosophy better than the philosophers can.

mundane things are composed of a galaxy of the unfamiliar.

In accordance with his wishes, his family had him cremated, and left his ashes out with the trash.

That same century witnessed the longest period of psychotic denial of this deep logical problem right at the center of this whole project!

I expect that the Copenhagen interpretation will some time be called the greatest sophism in the history of science,” he wrote to Wheeler in 1980, “but I would consider it a terrible injustice if—when some day a solution should be found—some people claim that ‘this is of course what Bohr always meant,’ only because he was sufficiently vague.

Heisenberg repeated his story about the German bomb program to anyone who would listen for the rest of his life. Goudsmit, who had access to the Farm Hall reports and had seen the pathetic remnants of the Nazi nuclear program firsthand, knew Heisenberg’s story was a fabrication. But, with the existence of the Farm Hall transcripts itself classified, Goudsmit could state only that Heisenberg was lying, without explaining how he knew. The first popular account of the Manhattan Project, Brighter Than a Thousand Suns, written by the Swiss journalist Robert Jungk in 1958, repeated Heisenberg’s story almost verbatim. So did The Virus House, the first book dedicated solely to the history of the German bomb program, which relied heavily on interviews from Heisenberg and his fellow former Farm Hall detainees. (The author, David Irving, was later revealed to be a Holocaust denier.)

I don’t believe a word of the whole thing,” said Heisenberg upon hearing the news. “I don’t believe it has anything to do with uranium.” Hahn jeered, “If the Americans have a uranium bomb then you’re all second raters. Poor old Heisenberg.” After they heard the BBC report the news in great detail later that night, Heisenberg and the others accepted the truth: they had been beaten. Over the next few days, Heisenberg attempted to work out how his project had fallen so far behind; his fumbling calculations show that he had never really understood how to even build a bomb in the first place, though he had certainly thought he’d understood it. And the bickering of the other scientists at Farm Hall confirmed what documents captured by Alsos had already suggested: the Nazi bomb program, unlike the Manhattan Project, was a disorganized mess, with vital information compartmentalized and no clear vision of how to proceed. Yet, in those same few days, the Farm Hall transcripts make it clear that Heisenberg and his student, Carl von Weizsäcker, purposefully constructed a revisionist narrative of their wartime activities. According to them, while the Americans had built a weapon of death and destruction on unprecedented scales, they, the Germans, had deliberately pursued only a nuclear reactor, being unwilling to build a massive new weapon for Hitler’s Reich—thereby placing the responsibility for their failure on their supposed moral clarity, rather than their sheer incompetence.

The debates about evolution, global warming, and homeopathy have been explicitly manufactured and funded by a variety of corporate, religious, and political entities from outside science, who are not in the least interested in the quest to divorce our human biases from our understanding of the world. They are not committed to taking the science seriously and are instead devoted to taking their own aims and giving them a thin patina of scientific respectability, enough to justify their claims to equal or greater validity than the existing and overwhelming scientific consensus. These groups are not interested in examining the data and happily reject it when it does not meet their preordained conclusions, inventing new “data” to suit their purposes. In the cases of global warming and evolution, these “controversies” were invented to push back against a perceived political agenda on the part of science and scientists. And the forces behind intelligent design and climate change denial were not wrong about that—science is political, and always has been, in that it informs decisions about the best policies in the public sphere, as well it should. And science certainly is a threat to the institutions pushing these antiscience agendas. Science will always be a political threat to some institutions, simply by virtue of its attempts to respect no authority other than data and logic. So much the worse for those institutions. And that’s another sign that these “debates” are not like the debate over quantum foundations—because those working against the scientific consensus are allied with (and often funded by) groups that are simply against the idea of science itself, like some fundamentalist religious groups.

It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.

Yet if Ellis and Silk had bothered to engage in such a dialogue before writing their editorial, they would have learned that Popper’s work hasn’t been taken seriously by philosophers of science for decades, and with good reason. The idea that falsifiability marks the boundary of science is vulnerable to the same arguments that made the verification theory of meaning untenable,

Shut up and calculate!” certainly doesn’t sound appealing if you’re not mathematically inclined. But, even if you’re a physicist, what’s the virtue in shutting up and calculating? Mermin himself provided the answer in his 1989 article. “It is a fact about the quantum theory of paramount importance which ought to be emphasized in every popular and semi-popular exposition, that it permits us to calculate measurable quantities with unprecedented precision.” Quantum physics works. The calculations enabled by the theory are astonishing in their range of applicability and the accuracy of their results. Quantum physics tells us how long it will take to heat up your frying pan to cook your eggs and how large a dying white dwarf star can be without collapsing. It reveals the exact shape of the double helix at the core of life, it tells us the age of the immortal cattle on the rock walls at Lascaux, it speaks of atoms split beneath the stone heart of Africa eons before Oppenheimer and the blinding light of Trinity. It predicts with uncanny accuracy the precise darkness of the blackest night. It shows us the history of the universe in a handful of dust. If shutting up is the price of doing these calculations, then pass the ball gag and break out the graph paper.

Everett thought that measurement, as presented in von Neumann’s textbook, was “a ‘magic’ process in which something quite drastic [occurs] (collapse of the wave function), while in all other times systems [are] assumed to obey perfectly natural continuous laws.” Measurement shouldn’t be fundamentally different from other physical processes. And even worse, according to Everett, von Neumann’s approach doesn’t even tell you what measurements are. If a measurement only happens when someone looks at a system, who, in particular, has to look? Everett argued that this line of reasoning leads inevitably to solipsism—the idea that you are the only being in the universe, and everyone else is somehow illusory or secondary, existing in states of indeterminate reality until you, the High Arbiter of Wave Function Collapse, deign to observe them. In his thesis, Everett admitted that this is an internally consistent view, but that “one must feel uneasy when, for example, writing textbooks on quantum mechanics, describing [wave function collapse], for the consumption of other persons to whom it does not apply.

The idea that something as pervasive and central as the Copenhagen interpretation might be dominant for 'accidental' nonscientific reasons can be scary, especially for people who have devoted their entire lives to physics.