The Collapsing Leviathan

May 26th, 2020

I was seriously depressed for the last week, by noticeably more than my baseline amount for the new pandemic-ravaged world. The depression seems to have been triggered by two pieces of news:

  1. The US Food and Drug Administration—yes, the same FDA whose failure to approve covid tests in February infamously set the stage for the deaths of 100,000 Americans—has now also banned the Gates Foundation’s program for at-home covid testing. This, it seems to me, is not the sort of thing that could happen in a still-functioning society, one where people valued their own and their neighbors’ physical survival, and viewed rules and regulations as merely instruments to that end. It’s the sort of thing that one imagines in the waning years of a doomed empire, when no one pretends anymore that they can fix or improve the Leviathan; they’re all just scurrying to flee the Leviathan as it collapses with a thud. More broadly, I still don’t think that the depth of America’s humiliation and downfall has sunk in to most Americans. For me, it starts and ends with a single observation: where fifty years ago we landed humans on the moon, today we can no longer make or distribute paper masks, even when hundreds of thousands of lives depend on it. Look, there are many countries, like Taiwan and New Zealand, that managed to protect both their economies and their vulnerable citizens’ lives, by crushing the virus early. Then there are countries that waited, until they faced an excruciating choice between the two. But here in the US, we’ve somehow achieved the worst of both worlds—triggering a second Great Depression while also utterly failing to control the virus. Can we abandon the charade of treating this as a legible “policy choice,” to be debated in earnest thinkpieces? To me, it just feels like the death-spasm of a collapsing Leviathan.
  2. Something that, at first glance, might seem trivial by comparison, but isn’t: the University of California system—ignoring the advice of its own Academic Senate, and at the apparent insistence of its chancellor Janet Napolitano—will now permanently end the use of the SAT and ACT in undergraduate admissions. This is widely expected, probably correctly, to trigger a chain reaction, whereby one US university after the next will abandon standardized tests. As a result, admissions to the top US universities—and hence, most chances for social advancement in the US—will henceforth be based entirely on shifting and nebulous criteria that rich, well-connected kids and their parents spend most of their lives figuring out, rather than merely mostly based on such criteria. The last side door for smart noncomformist kids is now being slammed shut. From now on, in the US, the only paths to success that clearly delineate their rules will be sports, gambling, reality TV, and the like. In case it matters to anyone reading this, I feel certain that a 15-year-old me wouldn’t stand a chance in the emerging regime—any more than nerdy Jewish kids did in the USSR of the 1970s, or the US of the 1920s. (As I’ve previously recounted on this blog, the US’s “holistic” college admissions system, with its baffling-to-foreigners emphasis on “character,” “leadership,” “well-roundedness,” etc. rather than test scores, originated in a successful push a century ago by the presidents of Harvard, Princeton, and Yale to keep Jewish enrollments down. Today the system fulfills precisely the same function, except against Asian-Americans rather than Jews.) Ironically but predictably, the death of the SAT—i.e., of one of the most fearsome weapons against entrenched wealth and power ever devised—is being celebrated by the self-described champions of the underdog. I have one question for those champions: do you not understand what your system will actually do to society’s underdogs? Or do you understand perfectly well, and approve?

To put it bluntly—since events like these leave no room for euphemism—a hundred thousand Americans are now dead from covid, and hundreds of thousands more are poised to die, because smart people are no longer in charge. And the death of the SAT will help ensure that smart people will never be back in charge. Obama might be remembered by history as America’s last smart-person-in-charge, its last competent technocrat—but one man couldn’t stop a tidal wave of stupid.

I know from experience what many will readers will say to all this: “instead of wallowing in gloom, Scott, why don’t you just make falsifiable predictions about the bad outcomes you expect from these developments, and then score yourself later?”

So here’s the thing about that.

Shortly after Trump was elected, I changed this blog’s background to black, as a small way to mourn the United States that I’d grown up thinking that I lived in, the one that had at least some ideals. Today, with four years of hindsight, my thinking then feels overly optimistic: why plain black? Why not, like, images of rotting corpses in a pit?

And yet, were I foolish enough to register predictions in 2016, I would’ve said that within one year, Trump’s staggering incompetence would surely cause some catastrophe or other to grip the country—a really obvious one, with mass death and even Trump’s beloved stock market cratering.

And then after a year, commenters would ridicule me, because none of that had happened. After two years, they’d ridicule me again because it still hadn’t happened, and after three years they’d ridicule me a third time.

Now it’s happened.

America, we now know, is like the cartoon character who runs off a cliff: it dangled in midair for three years, defying physics, before it finally looked down.

Look, I’m a theoretical computer scientist. By training, I deal in asymptotics, not in constant factors. I don’t often make predictions with deadlines; when I do, I often regret it. It’s a good thing that I became an academic rather than an investor! For I’ve learned that the only “oracular power” I have is to make statements like:

My eyes, my brain, and the pit of my stomach are all blaring at me that the asymptotics of this situation just took a sharp turn for the worse. Sure, for an unknown length of time, noise and constant factors could mask the effects. But eventually, either (1) society will need to reverse what it just did, or else (2) terrible effects will spring from it, or else (3) the entire universe no longer makes sense.

When I’ve felt this way in the past, option (3) rarely turned out to be the right answer.

So, what can anyone say that will make me less depressed? Thanks in advance!

Update (May 30): Woohoo!! Avoiding yet another tragedy, after years of setbacks and struggles, it looks like today the US has finally launched humans into orbit, thereby recapitulating a technological achievement from 1961 that the US had already vastly surpassed by 1969. I hereby retract the pessimism of this post.

Quantum Computing Lecture Notes 2.0

May 20th, 2020

Two years ago, I posted detailed lecture notes on this blog for my Intro to Quantum Information Science undergrad course at UT Austin. Today, with enormous thanks to UT PhD student Corey Ostrove, we’ve gotten the notes into a much better shape (for starters, they’re now in LaTeX). You can see the results here (7MB)—it’s basically a 260-page introductory quantum computing textbook in beta form, covering similar material as many other introductory quantum computing textbooks, but in my style for those who like that. It’s missing exercises, as well as material on quantum supremacy experiments, recent progress in hardware, etc., but that will be added in the next version if there’s enough interest. Enjoy!

Unrelated Announcement: Bjorn Poonen at MIT pointed me to researchseminars.org, a great resource for finding out about technical talks that are being held online in the era of covid. The developers recently added CS as a category, but so far there are very few CS talks listed. Please help fix that!

Four striking papers

May 13th, 2020

In the past week or two, four striking papers appeared on quant-ph. Rather than doing my usual thing—envisioning a huge, meaty blog post about each paper, but then procrastinating on writing them until the posts are no longer even relevant—I thought I’d just write a paragraph about each paper and then open things up for discussion.

(1) Matt Hastings has announced the first provable superpolynomial black-box speedup for the quantum adiabatic algorithm (in its original, stoquastic version). The speedup is only quasipolynomial (nlog(n)) rather than exponential, and it’s for a contrived example (just like in the important earlier work by Freedman and Hastings, which separated the adiabatic algorithm from Quantum Monte Carlo), and there are no obvious near-term practical implications. But still! Twenty years after Farhi and his collaborators wrote the first paper on the quantum adiabatic algorithm, and 13 years after D-Wave made its first hype-laden announcement, this is (to my mind) the first strong theoretical indication that adiabatic evolution with no sign problem can ever get a superpolynomial speedup over not only simulated annealing, not only Quantum Monte Carlo, but all possible classical algorithms. (This had previously been shown only for a variant of the adiabatic algorithm that jumps up to the first excited state, by Nagaj, Somma, and Kieferova.) As such, assuming the result holds up, Hastings resolves a central question that I (for one) had repeatedly asked about for almost 20 years. Indeed, if memory serves, at an Aspen quantum algorithms meeting a few years ago, I strongly urged Hastings to work on the problem. Congratulations to Matt!

(2) In my 2009 paper “Quantum Copy-Protection and Quantum Money,” I introduced the notion of copy-protected quantum software: a state |ψf⟩ that you could efficiently use to evaluate a function f, but not to produce more states (whether |ψf⟩ or anything else) that would let others evaluate f. I gave candidate constructions for quantumly copy-protecting the simple class of “point functions” (e.g., recognizing a password), and I sketched a proof that quantum copy-protection of arbitrary functions (except for those efficiently learnable from their input/output behavior) was possible relative to a quantum oracle. Building on an idea of Paul Christiano, a couple weeks ago my PhD student Jiahui Liu, Ruizhe Zhang, and I put a preprint on the arXiv improving that conclusion, to show that quantum copy-protection of arbitrary unlearnable functions is possible relative to a classical oracle. But my central open problem remained unanswered: is quantum copy-protection of arbitrary (unlearnable) functions possible in the real world, with no oracle? A couple days ago, Ananth and La Placa put up a preprint where they claim to show that the answer is no, assuming that there’s secure quantum Fully Homomorphic Encryption (FHE) of quantum circuits. I haven’t yet understood the construction, but it looks plausible, and indeed closely related to Barak et al.’s seminal proof of the impossibility of obfuscating arbitrary programs in the classical world. If this holds up, it (conditionally) resolves another of my favorite open problems—indeed, one that I recently mentioned in the Ask-Me-Anything session!

(3) Speaking of Boaz Barak: he, Chi-Ning Chou, and Xun Gao have a new preprint about a fast classical way to spoof Google’s linear cross-entropy benchmark for shallow random quantum circuits (with a bias that degrades exponentially with the depth, remaining detectable up to a depth of say ~√log(n)). As the authors point out, this by no means refutes Google’s supremacy experiment, which involved a larger depth. But along with other recent results in the same direction (e.g. this one), it does show that some exploitable structure is present even in random quantum circuits. Barak et al. achieve their result by simply looking at the marginal distributions on the individual output qubits (although the analysis to show that this works gets rather hairy). Boaz had told me all about this work when I saw him in person—back when traveling and meeting people in person was a thing!—but it’s great to see it up on the arXiv.

(4) Peter and Raphaël Clifford have announced a faster classical algorithm to simulate BosonSampling. To be clear, their algorithm is still exponential-time, but for the special case of a Haar-random scattering matrix, n photons, and m=n input and output modes, it runs in only ~1.69n time, as opposed to the previous bound of ~2n. The upshot is that, if you want to achieve quantum supremacy using BosonSampling, then either you need more photons than previously thought (maybe 90 photons? 100?), or else you need a lot of modes (in our original paper, Arkhipov and I recommended at least m~n2 modes for several reasons, but naturally the experimentalists would like to cut any corners they can).

And what about my own “research program”? Well yesterday, having previously challenged my 7-year-old daughter Lily with instances of comparison sorting, Eulerian tours, undirected connectivity, bipartite perfect matching, stable marriage, factoring, graph isomorphism, unknottedness, 3-coloring, subset sum, and traveling salesman, I finally introduced her to the P vs. NP problem! Even though Lily can’t yet formally define “polynomial,” let alone “algorithm,” I’m satisfied that she understands something of what’s being asked. But, in an unintended echo of one of my more controversial recent posts, Lily insists on pronouncing NP as “nip.”

Announcements

May 8th, 2020

Update (May 10): Extremely sorry to everyone who wanted to attend my SlateStarCodex talk on quantum necromancy, but wasn’t able due to technical problems! My PowerPoint slides are here; a recording might be made available later. Thanks to everyone who attended and asked great questions. Even though there were many, many bugs to be worked out, I found giving my first talk in virtual reality a fascinating experience; thanks so much to Patrick V. for inviting me and setting it up.

(1) I’ll be giving an online talk at SlateStarCodex (actually, in a VR room where you can walk around with your avatar, mingle, and even try to get “front-row seating”), this coming Sunday at 10:30am US Pacific time = 12:30pm US Central time (i.e., me) = 1:30pm US Eastern time = … Here’s the abstract:

Schrödinger’s Cat and Quantum Necromancy

I’ll try, as best I can, to give a 10-minute overview of the century-old measurement problem of quantum mechanics.  I’ll then discuss a new result, by me and Yosi Atia, that might add a new wrinkle to the problem.  Very roughly, our result says that if you had the technological ability, as measured by (say) quantum circuit complexity, to prove that a cat was in a coherent superposition of the alive and dead states, then you’d necessarily also have the technological ability to bring a dead cat back to life.  Of course, this raises the question of in what sense such a cat was ever “dead” in the first place.

(2) Robin Kothari has a beautiful blog post about a new paper by me, him, Avishay Tal, and Shalev Ben-David, which uses Huang’s recent breakthrough proof of the Sensitivity Conjecture to show that D(f)=O(Q(f)4) for all total Boolean functions f, where D(f) is the deterministic query complexity of f and Q(f) is the quantum query complexity—thereby resolving another longstanding open problem (the best known relationship since 1998 had been D(f)=O(Q(f)6)). Check out his post!

(3) For all the people who’ve been emailing me, and leaving blog comments, about Stephen Wolfram’s new model of fundamental physics (his new new kind of science?)—Adam Becker now has an excellent article for Scientific American, entitled Physicists Criticize Stephen Wolfram’s “Theory of Everything.” The article quotes me, friend-of-the-blog Daniel Harlow, and several others. The only thing about Becker’s piece that I disagreed with was the amount of space he spent on process (e.g. Wolfram’s flouting of traditional peer review). Not only do I care less and less about such things, but I worry that harping on them feeds directly into Wolfram’s misunderstood-genius narrative. Why not use the space to explain how Wolfram makes a hash of quantum mechanics—e.g., never really articulating how he proposes to get unitarity, or the Born rule, or even a Hilbert space? Anyway, given the demand, I guess I’ll do a separate blog post about this when I have time. (Keep in mind that, with my kids home from school, I have approximately 2 working hours per day.)

(4) Oh yeah, I forgot! Joshua Zelinsky pointed me to a website by Martin Ugarte, which plausibly claims to construct a Turing machine with only 748 states whose behavior is independent of ZF set theory—beating the previous claimed record of 985 states due to Stefan O’Rear (see O’Rear’s GitHub page), which in turn beat the 8000 states of me and Adam Yedidia (see my 2016 blog post about this). I should caution that, to my knowledge, the new construction hasn’t been peer-reviewed, let alone proved correct in a machine-checkable way (well, the latter hasn’t yet been done for any of these constructions). For that matter, while an absolutely beautiful interface is provided, I couldn’t even find documentation for the new construction. Still, Turing machine and Busy Beaver aficionados will want to check it out!

Vaccine challenge trials NOW!

May 1st, 2020

Update (May 5): Here’s a Quillette article making the case for human challenge trials. I think there’s an actual non-negligible chance that this cause will win—but every wasted day means thousands more dead.

I’ve asked myself again and again over the last few months: why are human challenge trials for covid vaccines not an ethical no-brainer? What am I missing that all the serious medical experts see? And what are we waiting for: for 10 million more to die? 20 million? So it made me feel a little less crazy that the world’s most famous living ethicist agrees.

I loved the way James Miller put it on my Facebook:

This is the trolley problem where the fat man wants to jump knowing his chance of death is below 1% and our decision is whether to stop him.

Like, suppose someone willingly sacrificed themselves so that doctors could use their body parts to save 10 million people. We might say: we would’ve lacked the strength to do the same in their place. We might say: we hope they weren’t pressured or coerced into it. But after the deed is done, is there anything to call this person but a hero, or even a martyr? Whatever we feel about the fireman who sacrifices his life in the course of saving 10 kids from a burning building, shouldn’t we feel it about this person a million times over? And of course, I deliberately made this vastly more extreme than the actual situation faced by young, healthy volunteers in a covid challenge trial, who in all likelihood would recover and be fine.

Regarding the obvious question: so would I volunteer to take an unproved vaccine, followed by a deliberate covid injection? Sure! Unfortunately, I might no longer be a candidate: I’m now nearing middle age and pre-diabetic, I help watch two young kids, and I live with two immunocompromised parents. But on the principle of walking the walk: if it were a vaccine candidate that I considered promising (and there are now several), and if it were practical to isolate me away from home for the requisite time, and if I could actually be of use, then absolutely, jab me.

On a somewhat related note: Last night I watched the Ender’s Game movie with my 7-year-old daughter Lily (neither of us had seen it; I’d read the book but only as a kid). Not surprisingly, the movie was a huge hit with Lily; she’s already begging to see it again. As for me, my first thought was: what a hackneyed sci-fi premise, that the entire human race is under attack from some alien species, and that all human children grow up in the shadow of that knowledge. Nothing whatsoever like the real world of 2020! My second thought was: what a quaint concept, that faced with a threat to humanity, the earth-authorities would immediately respond “quick, we need to find and train and cultivate super-geniuses willing to break the rules, and put them in command!” Only in the movies, never in real life! Except in, y’know, WWII, where that mindset was pretty crucial to the Allied victory? But 75 years later, yes, it reads to us as science fiction.

To inject a tiny note of optimism, I’m hopeful that we will eventually see some fruits of genius commensurate with the threat, whether in the realm of treatments or vaccines or contact-tracing apps or PPE or something else that no one’s thought of yet. Right now, though, the sad fact is this: as far as I know, the only indisputable work of genius to have arisen in response to the covid crisis has been the Twitter account for steak-umms.

Martinis, The Plot Against America, Kill Chain

April 23rd, 2020

Update (May 1): Check out this Forbes interview, where Martinis explains his reasons for leaving Google in much more detail.

As if we didn’t have enough to worry us, this week brought the sad news that John Martinis, who for five years was the leader and public face of Google’s experimental quantum computing effort, has quit Google and returned to his earlier post at UC Santa Barbara. I’ve spoken about what happened both with John and with Hartmut Neven, the head of Google’s Quantum AI Lab. Without betraying confidences, or asserting anything that either side would disagree with, I think I can say that it came down to a difference in management philosophies. Google tends to be consensus-driven, whereas John is of the view that building a million-qubit, error-corrected quantum computer will take more decisive leadership. I can add: I’d often wondered how John had time to travel the world, giving talks about quantum supremacy, while also managing the lab’s decisions on a day-to-day basis. It looks now like I was right to wonder! Potential analogies flood the mind: is this like a rock band that breaks up right after its breakout hit? Is it like Steve Jobs leaving Apple? Anyway, I wish the Google team the best in John’s absence, and I also wish John the best with whatever he does next.

I was never big on HBO (e.g., I still haven’t seen a single minute of Game of Thrones), but in the last couple of weeks, Dana and I found ourselves watching two absolutely compelling HBO shows—one a fictional miniseries and the other a documentary, but both on the theme of the fragility of American democracy.

The Plot Against America, based on the 2004 Philip Roth novel of the same name (which Dana read and which I now plan to read), is about an alternate history where the aviator Charles Lindbergh defeats FDR in the 1940 presidential election, on a fascist and isolationist platform, in events that—as countless people have pointed out—are eerily, terrifyingly prescient of what would actualy befall the US in 2016. The series follows a Jewish insurance salesman and his family in Newark, NJ—isn’t that what it always is with Philip Roth?—as they try to cope with the country’s gradual, all-too-plausible slide downward, from the genteel antisemitism that already existed in our timeline’s 1940 all the way to riots, assassinations, and pogroms (although never to an American Holocaust). One of the series’ final images is of paper ballots, in a rematch presidential election, being carted away and burned, underscoring just how much depends here on the mundane machinery of democracy.

Which brings me to Kill Chain: The Cyber War on America’s Elections, a documentary about the jaw-droppingly hackable electronic voting machines used in US elections and the fight to do something about them. The show mostly follows the journey of Harri Hursti, a Finnish-born programmer who’s made this issue his life’s work, but it also extensively features my childhood best friend Alex Halderman. OK, but isn’t this a theoretical issue, one that (perhaps rightly) exercises security nerds like Alex, but surely hasn’t changed the outcomes of actual elections?

Yeah, so about that. You know Brian Kemp, the doofus governor of Georgia, who’s infamously announced plans to reopen the state right away, ignoring the pleading of public health experts—a act that will fill Georgia’s ICUs and morgues as surely as night follows day? And you know how Kemp defeated the Democrat, Stacey Abrams, by a razor-thin margin, in a 2018 election of which Kemp himself was the overseer? It turns out that Kemp’s office distributed defective memory cards to African-American and Democratic precincts, though not to white and Republican ones. There’s also striking statistical evidence that at least some voting machines were hacked, although because there was no paper trail it can never be proved.

In short, what The Plot Against America and Kill Chain have in common is that they would be desperately needed warnings about the ease with which democracy could collapse in the US, except for the detail that much of what they warn about has already happened, and now it’s not clear how we get back.

AirToAll: Another guest post by Steve Ebin

April 20th, 2020

Scott’s foreword: Today I’m honored to host another guest post by friend-of-the-blog Steve Ebin, who not only published a beautiful essay here a month ago (the one that I titled “First it came from Wuhan”), but also posted an extremely informative timeline of what he understood when about the severity of the covid crisis, from early January until March 31st. By the latter date, Steve had quit his job, having made a hefty sum shorting airline stocks, and was devoting his full time to a new nonprofit to manufacture low-cost ventilators, called AirToAll. A couple weeks ago, Steve was kind enough to include me in one of AirToAll’s regular Zoom meetings; I learned more about pistons than I had in my entire previous life (admittedly, still not much). Which brings me to what Steve wants to talk about today: what he and others are doing and how you can help.

Without further ado, Steve’s guest post:

In my last essay on Coronavirus, I argued that Coronavirus will radically change society. In this blog post, I’d like to propose a structure for how we can organize to fight the virus. I will also make a call to action for readers of this blog to help a non-profit I co-founded, AirToAll, build safe, low-cost ventilators and other medical devices and distribute them across the world at scale.

There are four ways we can help fight coronavirus:

  1. Reduce exposure to the virus. Examples: learn where the virus is through better testing; attempt to be where the virus isn’t through social distancing, quarantining, and other means.
  2. Reduce the chance of exposure leading to infection. Examples: Wash your hands; avoid touching your face; wear personal protective equipment.
  3. Reduce the chance of infection leading to serious illness. Examples: improve your aerobic and pulmonary health; make it more difficult for coronavirus’s spike protein to bind to ACE-2 receptors; scale antibody therapies; consume adequate vitamin D; get more sleep; develop a vaccine.
  4. Reduce the chance of serious illness leading to death. Examples: ramp up the production and distribution of certain drugs; develop better drugs; build more ventilators; help healthcare workers.

Obviously, not every example I listed is practical, advisable, or will work, and some options, like producing a vaccine, may be better solutions than others. But we must pursue all approaches.

I’ve been devoting my own time to pursuing the fourth approach, reducing the chance that the illness will lead to death. Specifically, along with Neil Thanedar, I co-founded AirToAll, a nonprofit that helps bring low-cost, reliable, and clinically tested ventilators to market. I know lots of groups are working on this problem, so I thought I’d talk about it briefly.

First, like many groups, we’re designing our own ventilators. Although designing ventilators and bringing them to market at scale poses unique challenges, particularly in an environment where supply chains are strained, this is much easier than it must have been to build iron lungs in the early part of the 20th century, when Zoom conferencing wasn’t yet invented. When it comes to the ventilators we’re producing, we’re focused on safety and clinical validation rather than speed to market. We are not the farthest along here, but we’ve made good progress.

Second, our nonprofit is helping other groups produce safe and reliable ventilators by doing direct consultations with them and also by producing whitepapers to help them think through the issues at hand (h/t to Harvey Hawes, Abdullah Saleh, and our friends at ICChange).

Third, we’re working to increase the manufacturing capacity for currently approved ventilators.

The current shortage of ventilators is a symptom of a greater underlying problem: namely, the world is not good at recognizing healthcare crises early and responding to them quickly. While our nonprofit helps bring more ventilators to market, we are also trying to solve this greater underlying problem. I look at our work in ventilator-land as a first step towards our ultimate goal of making medical devices cheaper and more available through an open-source nonprofit model.

I am writing this post as a call to action to you, dear Shtetl-Optimized reader, to get involved.

You don’t have to be an engineer, pulmonologist, virologist, or epidemiologist to help us, although those skillsets are of course helpful and if you are we’d love to have you. If you have experience in data science and modeling, supply chain and manufacturing, public health, finance, operations, community management, or anything else a rapidly scaling organization needs, you can help us too. 

We are a group of 700+ volunteers and growing rapidly. If you’d like to help, we’d love to have you. If you might be interested in volunteering, click here. Donors click here. Everyone else, please email me at steven@airtoall.org and include a clear subject line so I can direct you to the right person.

Lockdown day 39

April 19th, 2020
  1. This is really getting depressing. One of the only things that makes it bearable—even though in some sense it shouldn’t—is that most of humanity is in this together. For once, there’s no question of “why me?”
  2. Having watched the eighth and final episode of Devs, the thought occurred to me: if I’d had the opportunity to restart the world from 8 months ago, even inside a simulation, I’d seize the chance and never look back.
  3. I think I finally figured out how to explain the issue with Devs to my literary sophisticate readers. Namely: Devs consists, precisely, of the cultural appropriation of quantum computing. Now, I never felt like cultural appropriation was the world’s worst problem—not even before a pandemic started overflowing the morgues—so I wouldn’t say I was offended by Alex Garland appropriating the images and buzzwords of my quantum computing tribe for a basically unrelated purpose, but it is what it is. Again: Devs is the show for you, if you want a haunting, slow-paced, well-produced meditation about free will and determinism and predicting the future and parallel worlds and “what if the whole universe is a simulation?,” and the various ideas I would’ve had about such topics around the age of 11. It’s just not a show about quantum computing. I hope that makes it clear.
  4. I read with interest this anonymous but PGP-signed article, laying out the case that it’s plausible that covid accidentally leaked from either the Wuhan Institute of Virology or the Wuhan CDC, rather than originating at the Huanan seafood market. Or, as an intermediate hypothesis, that an infected animal from one of those labs ended up at the seafood market. (Note that this is completely different from the hypothesis that covid was purposefully engineered—the authors of the article find that totally implausible, and I agree with them.) Notably, the Wuhan labs are known to have experimented with bat coronaviruses very much like covid, and are known to have performed “gain-of-function” experiments on them, and were probably the central labs in China for such experiments. And viruses are known to have leaked from other labs in China on other occasions, and the nature → seafood market route has unresolved issues, like where exactly the crossover from bats to pangolins (or some other intermediate species) is supposed to have happened, such that people would only start getting infected at the seafood market and not at its faraway suppliers, and … well, anyway, read the article and form your own judgment!
  5. I find it interesting that three months ago, I would’ve hesitated even to share such a link, because my internal critic would’ve screamed “this looks too much like tinfoil-hat stuff—are you ready for all the people you respect sneering at you?” But the me of three months ago is not the me of today. I make no apologies for adapting my thoughts to the freak branch of the multiverse where I actually find myself.

The quantum computer that knows all

April 14th, 2020

This is my first post in more than a month that’s totally unrelated to the covid crisis. Or rather, it’s related only insofar as it’s about a Hulu miniseries, the sort of thing that many of us have more occasion to watch while holed up at home.

Three weeks ago, a journalist named Ben Lindbergh—who’d previously asked me to comment on the scientific accuracy of Avengers: Endgame—asked me the same question about the miniseries Devs, which I hadn’t previously heard of.

[Warning: Spoilers follow]

‘Devs,’ I learned, is a spooky sci-fi action thriller about a secretive Silicon Valley company that builds a quantum computer that can perfectly reconstruct the past, down to what Jesus looked like on the cross, and can also (at least up to a point) predict the future.

And I was supposed, not only to endure such a show, but to comment on the accuracy of its invocations of quantum computing? This didn’t sound promising.

But, y’know, I was at home quarantined. So I agreed to watch the first episode. Which quickly turned into the second, third, fourth, fifth, sixth, and seventh episodes (the eighth and final one isn’t out yet).

It turns out that ‘Devs’ isn’t too bad, except that it’s not particularly about quantum computers. The latter is simply a buzzword chosen by the writers for a plot concept that would’ve been entirely familiar to the ancient Greeks, who called it the Delphic Oracle. You know, the mysterious entity that prophesies your fate, so then you try to escape the prophecy, but your very evasive maneuvers make the prophecy come true? Picture that, except with qubits—and for some reason, in a gleaming golden laboratory that has components that float in midair.

Devs Trailer Reveals New Look at FX-Hulu's Upcoming Limited Series
If you’re never visited a real quantum computing lab: they’re messier and a lot less golden.

At this point, I’ll just link you to Ben Lindbergh’s article about the show: Making Sense of the Science and Philosophy of ‘Devs.’ His long and excellent piece quotes me extensively enough that I see no need also to analyze the show in this blog post. (It also quotes several academic philosophers.)

Instead, I’ll just share a few tidbits that Ben left out, but that might be amusing to quantum computing fans.

  • The first episode opens with a conversation between two characters about how even “elliptical curve” cryptography is insecure against attack by quantum computers. So I immediately knew both that the writers had one or more consultants who actually knew something about QC, and also that those consultants were not as heavily involved as they could’ve been.
  • Similarly: in a later scene, some employees at the secretive company hold what appears to be a reading group about Shor’s algorithm. They talk about waves that interfere and cancel each other out, which is great, but beyond that their discussion sounded to me like nonsense. In particular, their idea seemed to be that the waves would reinforce at the prime factors p and q themselves, rather than at inverse multiples of the period of a periodic function that only indirectly encodes the factoring problem. (What do you say: should we let this one slide?)
  • “How many qubits does this thing have?” “A number that there would be no point in describing as a number.” ROFL
  • In the show, a crucial break comes when the employees abandon a prediction algorithm based on the deBroglie-Bohm pilot wave interpretation, and substitute one based on Everett’s many-worlds interpretation. Which I could actually almost believe, except that the many-worlds interpretation seems to contradict the entire premise of the rest of the show?
  • A new employee, after he sees the code of the superpowerful quantum computer for the first time, is so disoriented and overwhelmed that he runs and vomits into a toilet. I, too, have had that reaction to the claims of certain quantum computing companies, although in some sense for the opposite reason.

Anyway, none of the above addresses the show’s central conceit: namely, that the Laplace demon can be made real, the past and future rendered fully knowable (with at most occasional breaks and exceptions) by a machine that’s feasible to build. This conceit is fascinating to explore, but also false.

In the past, if you’d asked me to justify its falsity, I would’ve talked about chaos, and quantum mechanics, and the unknowability of the fine details of the universe’s state; I might’ve even pointed you to my Ghost in the Quantum Turing Machine essay. I also would’ve mentioned the severe conceptual difficulties in forcing Nature to find a fixed-point of a universe where you get to see your own future and act on that information (these difficulties are just a variant of the famous Grandfather Paradox).

But it occurs to me that, just as the coronavirus has now made plain the nature of exponential growth, even to the world’s least abstract-minded person, so too it’s made plain the universe’s unpredictability. Let’s put it this way: do you find it plausible that the quantum computer from ‘Devs,’ had you booted it up six months ago, would’ve known the exact state of every nucleotide in every virus in every bat in Wuhan? No? Then it wouldn’t have known our future.

And I see now that I’ve violated my promise that this post would have nothing to do with covid.

John Horton Conway (1937-2020)

April 12th, 2020

Update (4/13): Check out the comments on this post for some wonderful firsthand Conway stories. Or for the finest tribute I’ve seen so far, see a MathOverflow thread entitled Conway’s lesser known results. Virtually everything there is a gem to be enjoyed by amateurs and experts alike. And if you actually click through to any of Conway’s papers … oh my god, what a rebuke to the way most of us write papers!

John Horton Conway, one of the great mathematicians and math communicators of the past half-century, has died at age 82.

Update: John’s widow, Diana Conway, left a nice note in the comments section of this post. I wish to express my condolences to her and to all of the Conway children and grandchildren.

Just a week ago, as part of her quarantine homeschooling, I introduced my seven-year-old daughter Lily to the famous Conway’s Game of Life. Compared to the other stuff we’ve been doing, like fractions and right triangles and the distributive property of multiplication, the Game of Life was a huge hit: Lily spent a full hour glued to the screen, watching the patterns evolve, trying to guess when they’d finally die out. So this first-grader knew who John Conway was, when I told her the sad news of his passing.

“Did he die from the coronavirus?” Lily immediately asked.

“I doubt it, but I’ll check,” I said.

Apparently it was the coronavirus. Yes, the self-replicating snippet of math that’s now terrorizing the whole human race, in part because those in power couldn’t or wouldn’t understand exponential growth. Conway is perhaps the nasty bugger’s most distinguished casualty so far.

I regrettably never knew Conway, although I did attend a few of his wildly popular and entertaining lectures. His The Book of Numbers (coauthored with Richard Guy, who himself recently passed away at age 103) made a huge impression on me as a teenager. I worked through every page, gasping at gems like eπ√163 (“no, you can’t be serious…”), embarrassed to be learning so much from a “fun, popular” book but grateful that my ignorance of such basic matters was finally being remedied.

A little like Pascal with his triangle or Möbius with his strip, Conway was fated to become best-known to the public not for his deepest ideas but for his most accessible—although for Conway, a principal puzzle-supplier to Martin Gardner for decades, the boundary between the serious and the recreational may have been more blurred than for any other contemporary mathematician. Conway invented the surreal number system, discovered three of the 26 sporadic simple groups, was instrumental in the discovery of monstrous moonshine, and did many other things that bloggers more qualified than I will explain in the coming days.

Closest to my wheelhouse, Conway together with Simon Kochen waded into the foundations of quantum mechanics in 2006, with their “Free Will Theorem”—a result Conway liked to summarize provocatively as “if human experimenters have free will, then so do the elementary particles they measure.” I confess that I wasn’t a fan at the time—partly because Conway and Kochen’s theorem was really about “freshly-generated randomness,” rather than free will in any sense related to agency, but also partly because I’d already known the conceptual point at issue, but had considered it folklore (see, e.g., my 2002 review of Stephen Wolfram’s A New Kind of Science). Over time, though, the “Free Will Theorem” packaging grew on me. Much like with the No-Cloning Theorem and other simple enormities, sometimes it’s worth making a bit of folklore so memorable and compelling that it will never be folklore again.

At a lecture of Conway’s that I attended, someone challenged him that his proposed classification of knots worked only in special cases. “Oh, of course, this only classifies 0% of knots—but 0% is a start!” he immediately replied, to roars from the audience. That’s just one line that I remember, but nearly everything out of his mouth was of a similar flavor. I noted that part of it was in the delivery.

As a mathematical jokester and puzzler who could delight and educate anyone from a Fields Medalist to a first-grader, Conway had no equal. For no one else who I can think of, even going back centuries and millennia, were entertainment and mathematical depth so closely marbled together. Here’s to a well-lived Life.

Feel free to share your own Conway memories in the comments.