Donate to protect women’s rights: a call to my fellow creepy, gross, misogynist nerdbros

May 4th, 2022

So, I’d been planning a fun post for today about the DALL-E image-generating AI model, and in particular, a brief new preprint about DALL-E’s capabilities by Ernest Davis, Gary Marcus, and myself. We wrote this preprint as a sort of “adversarial collaboration”: Ernie and Gary started out deeply skeptical of DALL-E, while I was impressed bordering on awestruck. I was pleasantly surprised that we nevertheless managed to produce a text that we all agreed on.

Not for the first time, though, world events have derailed my plans. The most important part of today’s post is this:

For the next week, I, Scott Aaronson, will personally match all reader donations to Fund Texas Choice—a group that helps women in Texas travel to out-of-state health clinics, for reasons that are neither your business nor mine—up to a total of $5,000.

To show my seriousness, I’ve already donated $1,000. Just let me know how much you’ve donated in the comments section!

The first reason for this donation drive is that, perhaps like many of you, I stayed up hours last night reading Alito’s leaked decision in a state of abject terror. I saw how the logic of the decision, consistent and impeccable on its own terms, is one by which the Supreme Court’s five theocrats could now proceed to unravel the whole of modernity. I saw how this court, unchecked by our broken democratic system, can now permanently enshrine the will of a radical minority, perhaps unless and until the United States is plunged into a second Civil War.

Anyway, that’s the first reason for the donation drive. The second reason is to thank Shtetl-Optimized‘s commenters for their … err, consistently generous and thought-provoking contributions. Let’s take, for example, this comment on last week’s admittedly rather silly post, from an anonymous individual who calls herself “Feminist Bitch,” and who was enraged that it took me a full day to process one of the great political cataclysms of our lifetimes and publicly react to it:

OF COURSE. Not a word about Roe v. Wade being overturned, but we get a pseudo-intellectual rationalist-tier rant about whatever’s bumping around Scott’s mind right now. Women’s most basic reproductive rights are being curtailed AS WE SPEAK and not a peep from Scott, eh? Even though in our state (Texas) there are already laws ON THE BOOKS that will criminalize abortion as soon as the alt-right fascists in our Supreme Court give the go-ahead. If you cared one lick about your female students and colleagues, Scott, you’d be posting about the Supreme Court and helping feminist causes, not posting your “memes.” But we all know Scott doesn’t give a shit about women. He’d rather stand up for creepy nerdbros and their right to harass women than women’s right to control their own fucking bodies. Typical Scott.

If you want, you can read all of Feminist Bitch’s further thoughts about my failings, with my every attempt to explain and justify myself met with further contempt. No doubt my well-meaning friends of both sexes would counsel me to ignore her. Alas, from my infamous ordeal of late 2014, I know that with her every word, Feminist Bitch speaks for thousands, and the knowledge eats at me day and night.

It’s often said that “the right looks for converts, while the left looks only for heretics.” Has Feminist Bitch ever stopped to think about how our civilization reached its current terrifying predicament—how Trump won in 2016, how the Supreme Court got packed with extremists who represent a mere 25% of the country, how Putin and Erdogan and Orban and Bolsonaro and all the rest consolidated their power? Does she think it happened because wokeists like herself reached out too much, made too many inroads among fellow citizens who share some but not all of their values? Would Feminist Bitch say that, if the Democrats want to capitalize on the coming tsunami of outrage about the death of Roe and the shameless lies that enabled it, if they want to sweep to victory in the midterms and enshrine abortion rights into federal law … then their best strategy would be to double down on their condemnations of gross, creepy, smelly, white male nerdbros who all the girls, like, totally hate?

(until, thank God, some of them don’t)

I continue to think that the majority of my readers, of all races and sexes and backgrounds, are reasonable and sane. I continue to think the majority of you recoil against hatred and dehumanization of anyone—whether that means women seeking abortions, gays, trans folks, or (gasp!) even white male techbros. In this sad twilight for the United States and for liberal democracy around the world, we the reasonable and sane, we the fans of the Enlightenment, we the Party of Psychological Complexity, have decades of work cut out for us. For now I’ll simply say: I don’t hear from you nearly enough in the comments.

My first-ever attempt to create a meme!

April 27th, 2022

An update on the campaign to defend serious math education in California

April 26th, 2022

Update (April 27): Boaz Barak—Harvard CS professor, longtime friend-of-the-blog, and coauthor of my previous guest post on this topic—has just written an awesome FAQ, providing his personal answers to the most common questions about what I called our “campaign to defend serious math education.” It directly addresses several issues that have already come up in the comments. Check it out!


As you might remember, last December I hosted a guest post about the “California Mathematics Framework” (CMF), which was set to cause radical changes to precollege math in California—e.g., eliminating 8th-grade algebra and making it nearly impossible to take AP Calculus. I linked to an open letter setting out my and my colleagues’ concerns about the CMF. That letter went on to receive more than 1700 signatures from STEM experts in industry and academia from around the US, including recipients of the Nobel Prize, Fields Medal, and Turing Award, as well as a lot of support from college-level instructors in California. 

Following widespread pushback, a new version of the CMF appeared in mid-March. I and others are gratified that the new version significantly softens the opposition to acceleration in high school math and to calculus as a central part of mathematics.  Nonetheless, we’re still concerned that the new version promotes a narrative about data science that’s a recipe for cutting kids off from any chance at earning a 4-year college degree in STEM fields (including, ironically, in data science itself).

To that end, some of my Californian colleagues have issued a new statement today on behalf of academic staff at 4-year colleges in California, aimed at clearing away the fog on how mathematics is related to data science. I strongly encourage my readers on the academic staff at 4-year colleges in California to sign this commonsense statement, which has already been signed by over 250 people (including, notably, at least 50 from Stanford, home of two CMF authors).

As a public service announcement, I’d also like to bring to wider awareness Section 18533 of the California Education Code, for submitting written statements to the California State Board of Education (SBE) about errors, objections, and concerns in curricular frameworks such as the CMF.  

The SBE is scheduled to vote on the CMF in mid-July, and their remaining meeting before then is on May 18-19 according to this site, so it is really at the May meeting that concerns need to be aired.  Section 18533 requires submissions to be written (yes, snail mail) and postmarked at least 10 days before the SBE meeting. So to make your voice heard by the SBE, please send your written concern by certified mail (for tracking, but not requiring signature for delivery), no later than Friday May 6, to State Board of Education, c/o Executive Secretary of the State Board of Education, 1430 N Street, Room 5111, Sacramento, CA 95814, complemented by an email submission to sbe@cde.ca.gov and mathframework@cde.ca.gov.

On form versus meaning

April 24th, 2022

There is a fundamental difference between form and meaning. Form is the physical structure of something, while meaning is the interpretation or concept that is attached to that form. For example, the form of a chair is its physical structure – four legs, a seat, and a back. The meaning of a chair is that it is something you can sit on.

This distinction is important when considering whether or not an AI system can be trained to learn semantic meaning. AI systems are capable of learning and understanding the form of data, but they are not able to attach meaning to that data. In other words, AI systems can learn to identify patterns, but they cannot understand the concepts behind those patterns.

For example, an AI system might be able to learn that a certain type of data is typically associated with the concept of “chair.” However, the AI system would not be able to understand what a chair is or why it is used. In this way, we can see that an AI system trained on form can never learn semantic meaning.

–GPT3, when I gave it the prompt “Write an essay proving that an AI system trained on form can never learn semantic meaning” 😃

Back

April 23rd, 2022

Thanks to everyone who asked whether I’m OK! Yeah, I’ve been living, loving, learning, teaching, worrying, procrastinating, just not blogging.


Last week, Takashi Yamakawa and Mark Zhandry posted a preprint to the arXiv, “Verifiable Quantum Advantage without Structure,” that represents some of the most exciting progress in quantum complexity theory in years. I wish I’d thought of it. tl;dr they show that relative to a random oracle (!), there’s an NP search problem that quantum computers can solve exponentially faster than classical ones. And yet this is 100% consistent with the Aaronson-Ambainis Conjecture!


A student brought my attention to Quantle, a variant of Wordle where you need to guess a true equation involving 1-qubit quantum states and unitary transformations. It’s really well-done! Possibly the best quantum game I’ve seen.


Last month, Microsoft announced on the web that it had achieved an experimental breakthrough in topological quantum computing: not quite the creation of a topological qubit, but some of the underlying physics required for that. This followed their needing to retract their previous claim of such a breakthrough, due to the criticisms of Sergey Frolov and others. One imagines that they would’ve taken far greater care this time around. Unfortunately, a research paper doesn’t seem to be available yet. Anyone with further details is welcome to chime in.


Woohoo! Maximum flow, maximum bipartite matching, matrix scaling, and isotonic regression on posets (among many others)—all algorithmic problems that I was familiar with way back in the 1990s—are now solvable in nearly-linear time, thanks to a breakthrough by Chen et al.! Many undergraduate algorithms courses will need to be updated.


For those interested, Steve Hsu recorded a podcast with me where I talk about quantum complexity theory.

Nothing non-obvious to say…

February 24th, 2022

… but these antiwar protesters in St. Petersburg know that they’re all going to be arrested and are doing it anyway.

Meanwhile, I just spent an hour giving Lily, my 9-year-old, a crash course on geopolitics, including WWII, the Cold War, the formation of NATO, Article 5, nuclear deterrence, economic sanctions, the breakup of the USSR, Ukraine, the Baltic Republics, and the prospects now for WWIII. Her comment at the end was that from now on she’s going to refer to Putin as “Poopin,” in the hope that that shames him into changing course.

Update (March 1): A longtime Shtetl-Optimized reader has a friend who’s trying to raise funds to get her family out of Ukraine. See here if you’d like to help.

Happy 70th birthday Dad!

February 12th, 2022

When, before covid, I used to travel the world giving quantum computing talks, every once in a while I’d meet an older person who asked whether I had any relation to a 1970s science writer by the name of Steve Aaronson. So, yeah, Steve Aaronson is my dad. He majored in English in Penn State, where he was lucky enough to study under the legendary Phil Klass, who wrote under the pen name William Tenn and who basically created the genre of science-fiction comedy, half a century before there were any such things as Futurama. After graduating, my dad became a popular physics and cosmology writer, who interviewed greats like Steven Weinberg and John Archibald Wheeler and Arno Penzias (discoverer of the cosmic microwave background radiation). He published not only in science magazines but in Playboy and Penthouse, which (as he explained to my mom) paid better than the science magazines. When I was growing up, my dad had a Playboy on his office shelf, which I might take down if for example I wanted to show a friend a 2-page article, with an Aaronson byline, about the latest thinking on the preponderance of matter over antimatter in the visible universe.

Eventually, partly motivated by the need to make money to support … well, me, and then my brother, my dad left freelancing to become a corporate science writer at AT&T Bell Labs. There, my dad wrote speeches, delivered on the floor of Congress, about how breaking up AT&T’s monopoly would devastate Bell Labs, a place that stood with ancient Alexandria and Cambridge University among the human species’ most irreplaceable engines of scientific creativity. (Being a good writer, my dad didn’t put it in quite those words.) Eventually, of course, AT&T was broken up, and my dad’s dire warning about Bell Labs turned out to be 100% vindicated … although on the positive side, Americans got much cheaper long distance.

After a decade at Bell Labs, my dad was promoted to be a public relations executive at AT&T itself, where when I was a teenager, he was centrally involved in the launch of the AT&T spinoff Lucent Technologies (motto: “Bell Labs Innovations”), and then later the Lucent spinoff Avaya—developments that AT&T’s original breakup had caused as downstream effects.

In the 1970s, somewhere between his magazine stage and his Bell Labs stage, my dad also worked for Eugene Garfield, the pioneer of bibliometrics for scientific papers and founder of the Institute for Scientific Information, or ISI. (Sergey Brin and Larry Page would later cite Garfield’s work, on the statistics of the scientific-citation graph, as one of the precedents for the PageRank algorithm at the core of Google.)

My dad’s job at ISI was to supply Eugene Garfield with “raw material” for essays, which the latter would then write and publish in ISI’s journal Current Contents under the byline Eugene Garfield. Once, though, my dad supplied some “raw material” for a planned essay about “Style in Scientific Writing”—and, well, I’ll let Garfield tell the rest:

This topic of style in scientific writing was first proposed as something I should undertake myself, with some research and drafting help from Steve. I couldn’t, with a clear conscience, have put my name to the “draft” he submitted. And, though I don’t disagree with much of it, I didn’t want to modify or edit it in order to justify claiming it as my own. So here is Aaronson’s “draft,” as it was submitted for “review.” You can say I got a week’s vacation. After reading what he wrote it required little work to write this introduction.

Interested yet? You can read “Style in Scientific Writing” here. You can, if we’re being honest, tell that this piece was originally intended as “raw material”—but only because of the way it calls forth such a fierce armada of all of history’s awesomest quotations about what makes scientific writing good or bad, like Ben Franklin and William James and the whole gang, which would make it worth the read regardless. I love eating raw dough, I confess, and I love my dad’s essay. (My dad, ironically enough, likes everything he eats to be thoroughly cooked.)

When I read that essay, I hear my dad’s voice from my childhood. “Omit needless words.” There were countless revisions and pieces of advice on every single thing I wrote, but usually, “omit needless words” was the core of it. And as terrible as you all know me to be on that count, imagine how much worse it would’ve been if not for my dad! And I know that as soon as he reads this post, he’ll find needless words to omit.

But hopefully he won’t omit these:

Happy 70th birthday Pops, congrats on beating the cancer, and here’s to many more!

AlphaCode as a dog speaking mediocre English

February 6th, 2022

Tonight, I took the time actually to read DeepMind’s AlphaCode paper, and to work through the example contest problems provided, and understand how I would’ve solved those problems, and how AlphaCode solved them.

It is absolutely astounding.

Consider, for example, the “n singers” challenge (pages 59-60). To solve this well, you first need to parse a somewhat convoluted English description, discarding the irrelevant fluff about singers, in order to figure out that you’re being asked to find a positive integer solution (if it exists) to a linear system whose matrix looks like
1 2 3 4
4 1 2 3
3 4 1 2
2 3 4 1.
Next you need to find a trick for solving such a system without Gaussian elimination or the like (I’ll leave that as an exercise…). Finally, you need to generate code that implements that trick, correctly handling the wraparound at the edges of the matrix, and breaking and returning “NO” for any of multiple possible reasons why a positive integer solution won’t exist. Oh, and also correctly parse the input.

Yes, I realize that AlphaCode generates a million candidate programs for each challenge, then discards the vast majority by checking that they don’t work on the example data provided, then still has to use clever tricks to choose from among the thousands of candidates remaining. I realize that it was trained on tens of thousands of contest problems and millions of solutions to those problems. I realize that it “only” solves about a third of the contest problems, making it similar to a mediocre human programmer on these problems. I realize that it works only in the artificial domain of programming contests, where a complete English problem specification and example inputs and outputs are always provided.

Forget all that. Judged against where AI was 20-25 years ago, when I was a student, a dog is now holding meaningful conversations in English. And people are complaining that the dog isn’t a very eloquent orator, that it often makes grammatical errors and has to start again, that it took heroic effort to train it, and that it’s unclear how much the dog really understands.

It’s not obvious how you go from solving programming contest problems to conquering the human race or whatever, but I feel pretty confident that we’ve now entered a world where “programming” will look different.

Update: A colleague of mine points out that one million, the number of candidate programs that AlphaCode needs to generate, could be seen as roughly exponential in the number of lines of the generated programs. If so, this suggests a perspective according to which DeepMind has created almost the exact equivalent, in AI code generation, of a non-fault-tolerant quantum computer that’s nevertheless competitive on some task (as in the quantum supremacy experiments). I.e., it clearly does something highly nontrivial, but the “signal” is still decreasing exponentially with the number of instructions, necessitating an exponential number of repetitions to extract the signal and imposing a limit on the size of the programs you can scale to.

Scott Aaronson Speculation Grant WINNERS!

February 4th, 2022

Two weeks ago, I announced on this blog that, thanks to the remarkable generosity of Jaan Tallinn, and the Speculation Grants program of the Survival and Flourishing Fund that Jaan founded, I had $200,000 to give away to charitable organizations of my choice. So, inspired by what Scott Alexander had done, I invited the readers of Shtetl-Optimized to pitch their charities, mentioning only some general areas of interest to me (e.g., advanced math education at the precollege level, climate change mitigation, pandemic preparedness, endangered species conservation, and any good causes that would enrage the people who attack me on Twitter).

I’m grateful to have gotten more than twenty well-thought-out pitches; you can read a subset of them in the comment thread. Now, having studied them all, I’ve decided—as I hadn’t at the start—to use my entire allotment to make as strong a statement as I can about a single cause: namely, subject-matter passion and excellence in precollege STEM education.

I’ll be directing funds to some shockingly cash-starved math camps, math circles, coding outreach programs, magnet schools, and enrichment programs, in Maine and Oregon and England and Ghana and Ethiopia and Jamaica. The programs I’ve chosen target a variety of ability levels, not merely the “mathematical elite.” Several explicitly focus on minority and other underserved populations. But they share a goal of raising every student they work with as high as possible, rather than pushing the students down to fit some standardized curriculum.

Language like that ought to be meaningless boilerplate, but alas, it no longer is. We live in a time when the state of California, in a misguided pursuit of “modernization” and “equity,” is poised to eliminate 8th-grade algebra, make it nearly impossible for high-school seniors to take AP Calculus, and shunt as many students as possible from serious mathematical engagement into a “data science pathway” that in practice might teach little more than how to fill in spreadsheets. (This watering-down effort now itself looks liable to be watered down—but only because of a furious pushback from parents and STEM professionals, pushback in which I’m proud that this blog played a small role.) We live in a time when elite universities are racing to eliminate the SAT—thus, for all their highminded rhetoric, effectively slamming the door on thousands of nerdy kids from poor or immigrant backgrounds who know how to think, but not how to shine in a college admissions popularity pageant. We live in a time when America’s legendary STEM magnet high schools, from Thomas Jefferson in Virginia to Bronx Science to Lowell in San Francisco, rather than being celebrated as the national treasures that they are, or better yet replicated, are bitterly attacked as “elitist” (even while competitive sports and music programs are not similarly attacked)—and are now being forcibly “demagnetized” by bureaucrats, made all but indistinguishable from other high schools, over the desperate pleas of their students, parents, and alumni.

And—alright, fine, on a global scale, arresting climate change is surely a higher-priority issue than protecting the intellectual horizons of a few teenage STEM nerds. The survival of liberal democracy is a higher-priority issue. Pandemic preparedness, poverty, malnutrition are higher-priority issues. Some of my friends strongly believe that the danger of AI becoming super-powerful and taking over the world is the highest-priority issue … and truthfully, with this week’s announcements of AlphaCode and OpenAI’s theorem prover, which achieve human-competitive performance in elite programming and math competitions respectively, I can’t confidently declare that they’re wrong.

On the other hand, when you think about the astronomical returns on every penny that was invested in setting a teenage Ramanujan or Einstein or Turing or Sofya Kovalevskaya or Norman Borlaug or Mario Molina onto their trajectories in life … and the comically tiny budgets of the world-leading programs that aim to nurture the next Ramanujans, to the point where $10,000 often seems like a windfall to those programs … well, you might come to the conclusion that the “protecting nerds” thing actually isn’t that far down the global priority list! Like, it probably cracks the top ten.

And there’s more to it than that. There’s a reason beyond parochialism, it dawned on me, why individual charities tend to specialize in wildlife conservation in Ecuador or deworming in Swaziland or some other little domain, rather than simply casting around for the highest-priority cause on earth. Expertise matters—since one wants to make, not only good judgments about which stuff to support, but good judgments that most others can’t or haven’t made. In my case, it would seem sensible to leverage the fact that I’m Scott Aaronson. I’ve spent much of my career in math/CS education and outreach—mostly, of course, at the university level, but by god did I personally experience the good and the bad in nearly every form of precollege STEM education! I’m pretty confident in my ability to distinguish the two, and for whatever I don’t know, I have close friends in the area who I trust.

There’s also a practical issue: in order for me to fund something, the recipient has to fill out a somewhat time-consuming application to SFF. If I’d added, say, another $20,000 drop into the bucket of global health or sustainability or whatever, there’s no guarantee that the intended recipients of my largesse would even notice, or care enough to go through the application process if they did. With STEM education, by contrast, holy crap! I’ve got an inbox full of Shtetl-Optimized readers explaining how their little math program is an intellectual oasis that’s changed the lives of hundreds of middle-schoolers in their region, and how $20,000 would mean the difference between their program continuing or not. That’s someone who I trust to fill out the form.

Without further ado, then, here are the first-ever Scott Aaronson Speculation Grants:

  • $57,000 for Canada/USA Mathcamp, which changed my life when I attended it as a 15-year-old in 1996, and which I returned to as a lecturer in 2008. The funds will be used for COVID testing to allow Mathcamp to resume in-person this summer, and perhaps scholarships and off-season events as well.
  • $30,000 for AddisCoder, which has had spectacular success teaching computer science to high-school students in Ethiopia, placing some of its alumni at elite universities in the US, to help them expand to a new “JamCoders” program in Jamaica. These programs were founded by UC Berkeley’s amazing Jelani Nelson, also with involvement from friend and Shtetl-Optimized semi-regular Boaz Barak.
  • $30,000 for the Maine School of Science and Mathematics, which seems to offer a curriculum comparable to those of Thomas Jefferson, Bronx Science, or the nation’s other elite magnet high schools, but (1) on a shoestring budget and (2) in rural Maine. I hadn’t even heard of MSSM before Alex Altair, an alum and Shtetl-Optimized reader, told me about it, but now I couldn’t be prouder to support it.
  • $30,000 for the Eugene Math Circle, which provides a math enrichment lifeline to kids in Oregon, and whose funding was just cut. This donation will keep the program alive for another year.
  • $13,000 for the Summer Science Program, which this summer will offer research experiences to high-school juniors in astrophysics, biochemistry, and genomics.
  • $10,000 for the MISE Foundation, which provides math enrichment for the top middle- and high-school students in Ghana.
  • $10,000 for Number Champions, which provides one-on-one coaching to kids in the UK who struggle with math.
  • $10,000 for Bridge to Enter Advanced Mathematics (BEAM), which runs math summer programs in New York, Los Angeles, and elsewhere for underserved populations.
  • $10,000 for Powderhouse, an innovative lab school being founded in Somerville, MA.

While working on this, it crossed my mind that, on my deathbed, I might be at least as happy about having directed funds to efforts like these as about any of my research or teaching.

To the applicants who weren’t chosen: I’m sorry, as many of you had wonderful projects too! As I said in the earlier post, you remain warmly invited to apply to SFF, and to make your pitch to the other Speculators and/or the main SFF committee.

Needless to say, anyone who feels inspired should add to my (or rather, SFF’s) modest contributions to these STEM programs. My sense is that, while $200k can go eye-poppingly far in this area, it still hasn’t come close to exhausting even the lowest-hanging fruit.

Also needless to say, the opinions in this post are my own and are not necessarily shared by SFF or by the organizations I’m supporting. The latter are welcome to disagree with me as long as they keep up their great work!

Huge thanks again to Jaan, to SFF, to my SFF contact Andrew Critch, to everyone (whether chosen or not) who participated in this contest, and to everyone who’s putting in work to broaden kids’ intellectual horizons or otherwise make the world a little less horrible.

Why Quantum Mechanics?

January 25th, 2022

In the past few months, I’ve twice injured the same ankle while playing with my kids. This, perhaps combined with covid, led me to several indisputable realizations:

  1. I am mortal.
  2. Despite my self-conception as a nerdy little kid awaiting the serious people’s approval, I am now firmly middle-aged. By my age, Einstein had completed general relativity, Turing had founded CS, won WWII, and proposed the Turing Test, and Galois, Ramanujan, and Ramsey had been dead for years.
  3. Thus, whatever I wanted to accomplish in my intellectual life, I should probably get started on it now.

Hence today’s post. I’m feeling a strong compulsion to write an essay, or possibly even a book, surveying and critically evaluating a century of ideas about the following question:

Q: Why should the universe have been quantum-mechanical?

If you want, you can divide Q into two subquestions:

Q1: Why didn’t God just make the universe classical and be done with it? What would’ve been wrong with that choice?

Q2: Assuming classical physics wasn’t good enough for whatever reason, why this specific alternative? Why the complex-valued amplitudes? Why unitary transformations? Why the Born rule? Why the tensor product?

Despite its greater specificity, Q2 is ironically the question that I feel we have a better handle on. I could spend half a semester teaching theorems that admittedly don’t answer Q2, as satisfyingly as Einstein answered the question “why the Lorentz transformations?,” but that at least render this particular set of mathematical choices (the 2-norm, the Born Rule, complex numbers, etc.) orders-of-magnitude less surprising than one might’ve thought they were a priori. Q1 therefore stands, to me at least, as the more mysterious of the two questions.

So, I want to write something about the space of credible answers to Q, and especially Q1, that humans can currently conceive. I want to do this for my own sake as much as for others’. I want to do it because I regard Q as one of the biggest questions ever asked, for which it seems plausible to me that there’s simply an answer that most experts would accept as valid once they saw it, but for which no such answer is known. And also because, besides having spent 25 years working in quantum information, I have the following qualifications for the job:

  • I don’t dismiss either Q1 or Q2 as silly; and
  • crucially, I don’t think I already know the answers, and merely need better arguments to justify them. I’m genuinely uncertain and confused.

The purpose of this post is to invite you to share your own answers to Q in the comments section. Before I embark on my survey project, I’d better know if there are promising ideas that I’ve missed, and this blog seems like as good a place as any to crowdsource the job.

Any answer is welcome, no matter how wild or speculative, so long as it honestly grapples with the actual nature of QM. To illustrate, nothing along the lines of “the universe is quantum because it needs to be holistic, interconnected, full of surprises, etc. etc.” will cut it, since such answers leave utterly unexplained why the world wasn’t simply endowed with those properties directly, rather than specifically via generalizing the rules of probability to allow interference and noncommuting observables.

Relatedly, whatever “design goal” you propose for the laws of physics, if the goal is satisfied by QM, but satisfied even better by theories that provide even more power than QM does—for instance, superluminal signalling, or violations of Tsirelson’s bound, or the efficient solution of NP-complete problems—then your explanation is out. This is a remarkably strong constraint.

Oh, needless to say, don’t try my patience with anything about the uncertainty principle being due to floating-point errors or rendering bugs, or anything else that relies on a travesty of QM lifted from a popular article or meme! 🙂

OK, maybe four more comments to enable a more productive discussion, before I shut up and turn things over to you:

  1. I’m aware, of course, of the radical uncertainty about what form an answer to Q should even take. Am I asking you to psychoanalyze the will of God in creating the universe? Or, what perhaps amounts to the same thing, am I asking for the design objectives of the giant computer simulation that we’re living in? (As in, “I’m 100% fine with living inside a Matrix … I just want to understand why it’s a unitary matrix!”) Am I instead asking for an anthropic explanation, showing why of course QM would be needed if you wanted life or consciousness like ours? Am I “merely” asking for simpler or more intuitive physical principles from which QM is to be derived as a consequence? Am I asking why QM is the “most elegant choice” in some space of mathematical options … even to the point where, with hindsight, a 19th-century mathematician or physicist could’ve been convinced that of course this must be part of Nature’s plan? Am I asking for something else entirely? You get to decide! Should you take up my challenge, this is both your privilege and your terrifying burden.
  2. I’m aware, of course, of the dizzying array of central physical phenomena that rely on QM for their ultimate explanation. These phenomena range from the stability of matter itself, which depends on the Pauli exclusion principle; to the nuclear fusion that powers the sun, which depends on a quantum tunneling effect; to the discrete energy levels of electrons (and hence, the combinatorial nature of chemistry), which relies on electrons being waves of probability amplitude that can only circle nuclei an integer number of times if their crests are to meet their troughs. Important as they are, though, I don’t regard any of these phenomena as satisfying answers to Q in themselves. The reason is simply that, in each case, it would seem like child’s-play to contrive some classical mechanism to produce the same effect, were that the goal. QM just seems far too grand to have been the answer to these questions! An exponentially larger state space for all of reality, plus the end of Newtonian determinism, just to overcome the technical problem that accelerating charges radiate energy in classical electrodynamics, thereby rendering atoms unstable? It reminds me of the Simpsons episode where Homer uses a teleportation machine to get a beer from the fridge without needing to get up off the couch.
  3. I’m aware of Gleason’s theorem, and of the specialness of the 1-norm and 2-norm in linear algebra, and of the arguments for complex amplitudes as opposed to reals or quaternions, and of the beautiful work of Lucien Hardy and of Chiribella et al. and others on axiomatic derivations of quantum theory. As some of you might remember, I even discussed much of this material in Quantum Computing Since Democritus! There’s a huge amount to say about these fascinating justifications for the rules of QM, and I hope to say some of it in my planned survey! For now, I’ll simply remark that every axiomatic reconstruction of QM that I’ve seen, impressive though it was, has relied on one or more axioms that struck me as weird, in the sense that I’d have little trouble dismissing the axioms as totally implausible and unmotivated if I hadn’t already known (from QM, of course) that they were true. The axiomatic reconstructions do help me somewhat with Q2, but little if at all with Q1.
  4. To keep the discussion focused, in this post I’d like to exclude answers along the lines of “but what if QM is merely an approximation to something else?,” to say nothing of “a century of evidence for QM was all just a massive illusion! LOCAL HIDDEN VARIABLES FOR THE WIN!!!” We can have those debates another day—God knows that, here on Shtetl-Optimized, we have and we will. Here I’m asking instead: imagine that, as fantastical as it sounds, QM were not only exactly true, but (along with relativity, thermodynamics, evolution, and the tastiness of chocolate) one of the profoundest truths our sorry species had ever discovered. Why should I have expected that truth all along? What possible reasons to expect it have I missed?