Category Archives: America Is a Failed Experiment

On Being a Quantum Physicist in Autumn 2019

(a friendly warning for police violence, transphobia and philosophy of physics)

The way I see it, the two big Why? questions about quantum mechanics are, first, why do we use the particular mathematical apparatus of quantum theory, as opposed to any alternative we might imagine? And second, why do we only find it necessary to work with the full perplexities of quantum physics some of the time? These two questions are related. In order to understand how imprecise measurements might wash out quantum weirdness, we need to characterize which features of quantum theory really are fundamentally weird. And this, in turn, requires separating deep principles from convenient conventions and illuminating the true core of the physics. My own research has focused on the first question, but the second is never too far from my mind.

Of course, I have a lot on my mind these days, but I don’t think I’m special in that regard.

If you ask me, a “quantum system” can be any part of nature that is subject to an agent’s inquiry. A “quantum measurement” is, in principle, any action that an agent takes upon a quantum system. The road between Boston’s City Hall and the Holocaust Memorial is a quantum system. When the police use their bicycles as battering rams against queer kids and street medics, running towards the trouble is a quantum measurement. Being threatened with pepper spray, while secoondhand exposure already stings the eye and throat, one human thrown to the pavement in the intersection in front of you while another arrest happens on the sidewalk just behind you, is an outcome of that measurement. Unsurprisingly, textbooks provide little guidance on casting that event into the algebraic formalism of density matrices, and in the moment, other types of expertise are more immediately useful.

I first encountered quantum physics in a serious way during the spring of my second year at university — 2003, that would have been. I did not particularly care about the conceptual or philosophical “foundations” of it until the summer of 2010. The interval in between encompassed six semesters of quantum mechanics and subjects dependent upon it, along with my first attempts to find a research problem in the area. Once my curiosity had been provoked, it took the better part of a year to find an “interpretation” of quantum mechanics that was at all satisfying, and longer than that to make the transition from “this is how a member of that school would answer that question” to “this is what I declare myself”. Part of that transition was my discovery that I could put my own stamp on the ideas: The concepts and the history provoked new mathematical questions, which I could approach with a background that nobody else had.

The interpretation I adopted was the QBism of Chris Fuchs and Rüdiger Schack, later joined by N. David Mermin.

QBism is

an interpretation of quantum mechanics in which the ideas of agent and experience are fundamental. A “quantum measurement” is an act that an agent performs on the external world. A “quantum state” is an agent’s encoding of her own personal expectations for what she might experience as a consequence of her actions. Moreover, each measurement outcome is a personal event, an experience specific to the agent who incites it. Subjective judgments thus comprise much of the quantum machinery, but the formalism of the theory establishes the standard to which agents should strive to hold their expectations, and that standard for the relations among beliefs is as objective as any other physical theory.

That’s how we put it in the FAQ. Any physicist who is weird enough to endorse an interpretation of quantum mechanics will naturally get inquiries about it. Many of these, we get often enough that we try to compile good answers together into a nicely portable package — with the proviso that the quantum is a project, and some answers are not final because if physics were easy, we’d be done by now.

There’s a question which seems particularly suited to answering in the blog format, though: “Why don’t you believe in the Many Worlds Interpretation?”
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It Is a Heartbreakingly Lovely Spring Day

When I was a prickly atheist teenager, I did not appreciate the Battle Hymn of the Republic. After all, it was one of the bad guys’ songs in Inherit the Wind, wasn’t it? Much later, I realized — oh, it was written by an abolitionist in 1861. She was thirsty to see the fields watered with slaveowner blood. OK then. More terrible swift sword, please.

When I was a prickly atheist teenager, I was rather confident that the people who put “evolution is just a theory” stickers in all our biology books would be Good Germans if given the chance.

Turns out? I was right.

If I had foreseen that organized atheism would descend into sexism and xenophobia, then I would give myself credit. Yes, pretty much as soon as I met a convention-ful of skeptics, I found myself ill at ease with the blithe acceptance of economic injustice, and vaguely surprised by how easily the cogs of critical thinking were disengaged once the conversation moved beyond “UFOs, aspirin commercials, and 35,000-year-old channelees”. I should have been more upset, and sooner.

When I was a university student, I wrote a sestina in the voice of Persephone, mourning her life, with the trick ending that she’s a goth girl and wishes she had eaten more of the pomegranate seeds so that she could groove on the underworld for a longer fraction of the year. This may be indicative of my type of indulgence then.

When I was a university student, I began a novel. Like any youngster who has just discovered layering and allusion — anagrams with doctorates — I went full in, under the spell of Pale Fire and Appel’s Annotated Lolita and elective courses on hypertext fiction. I am sure the result would in many places embarrass me now, though at least I am still fond of this sample. I doubt I had the stylistic control to make all of my attempts at subversion be more than recapitulations. In retrospect, one character seems, within the strictures of a “romance” subplot, to be discovering their own asexuality. A better writer would have done more with that. And the motives of my off-screen villains now feel a bit too armchair, too intellectualized, when simple misogynist fury would suffice.

Also, I underplayed climate change, treating it as a diegetic justification for a mild surrealism, a reason for the world to be reshaped — under a spell, again, this time of Borges’ “Death and the Compass”.

You see, I finished that novel in 2008, when plenty was wrong with the world, but matters were sufficiently good for sufficiently many that it felt we could make things right, if we only worked hard.

When I was younger, I found that “Holy Writ” was habitually obscure, frequently cruel and almost always in need of an editor. Now, as we are poised to inherit the heated wind, I would add that the best reason to know the story of Abraham nearly sacrificing Isaac is to appreciate the twist ending that Wilfred Owen gave it:

But the old man would not so, but slew his son,
And half the seed of Europe, one by one.

Grim

Maybe I need an “I told you so” category for this blog. Quoting the kicker from The Atlantic‘s portrayal of the State Department:

“This is probably what it felt like to be a British foreign service officer after World War II, when you realize, no, the sun actually does set on your empire,” said the mid-level officer. “America is over. And being part of that, when it’s happening for no reason, is traumatic.”

The American Physical Society Finally Speaks

The APS, my professional organization, has made some dunderheaded moves of late, but this is more encouraging. An email from the APS president and CEO, broadcast today to the membership at large, begins thusly:

We share the concerns expressed by many APS members about recent U.S. government actions that will harm the open environment that is essential for a successful global scientific enterprise. The recent executive order regarding immigration, and in particular, its implementation, would reduce participation of international scientists and students in U.S. research, industry, education, and conference activities, and sends a chilling message to scientists internationally.

The American Chemical Society had already spoken up:
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Shorter Pinker

Wasn’t I just kvetching about Steven Pinker? Not that long ago, even? Well, some gifts just won’t stop giving. He’s at it again, this time complaining about the “anti-science PC/identity politics/hard-left rhetoric” of the March for Science. It might have been obvious to some of us ten years or more ago that basic respect for empirical data had become a partisan issue, but not everybody has caught up quite yet.

An academic type like me has a hard time responding to accusations of “identity politics” or “political correctness,” not because the accusations have any intellectual merit, but because the real message isn’t the words on the page. People like me, we see a thing wrapped up in the form of a scholarly argument, and we try to respond with footnotes and appendices. But the clauses and locutions are just dances around the real issue, the fundamental point that was expressed most clearly by the Twitter account @ProBirdRights:

I am feel uncomfortable when we are not about me?

Science Is Now the Enemy

No, let’s be a little more forceful than that. The news warrants that much, and it just keeps coming. For the party now in power, the people who keep rat shit out of your food and stop rivers from catching on fire are now the enemy.

I’m really not feeling that good about our ability to handle the next epidemic that comes our way.

And on a personal note, I’m a queer scientist who has published on biological evolution and the need for financial regulation. So, you can sod off with your cheery hot takes about America becoming Great Again through space exploration, or whatever the Quisling line is this week. Stuff your white dick back in your pants and sit your ass down while the adults work, m’kay?

As Of Today

The United States of America is a failed experiment.

We went out in the way a bad joke would have predicted. We lost against our own racism and sexism, our endemic illnesses whose symptoms were intensified by corrupt law enforcement and institutionally rotten mass media. Undone at the final hour by a bizarre codicil in a slaveowners’ constitution. Undone, pushed over the edge—but the edge was too close all along. When it really mattered, we proved ourselves incompetent: not able to handle our civil responsibilities, indeed, in a sense, not ready for adulthood. In the name of national glory, we have voted ourselves a government of the worst. And now a generation will grow up ignorant, poor and sick, if they get the chance to grow up at all. Many of the things we will lose will be things we can never regain, from international respect to endangered species to the lives of our loved ones.

Many good people will keep up the good fight and stir up, as John Lewis says, the good trouble.

The abyss has opened before us.

Whether the future we make for ourselves will have anything to commend it now depends upon our ability to stare into that abyss and make it blink.