Shtetl-Optimized

I was saddened about the results of the Israeli election. The Beresheet lander, which lost its engine and crashed onto the moon as I was writing this, seems like a fitting symbol for where the country is now headed. Whatever he was at the start of his career, Netanyahu has become the Israeli Trump—a breathtakingly corrupt strongman who appeals to voters’ basest impulses, sacrifices his country’s future and standing in the world for short-term electoral gain, considers himself unbound by laws, recklessly incites hatred of minorities, and (despite zero personal piety) cynically panders to religious fundamentalists who help keep him in power. Just like with Trump, it’s probably futile to hope that lawyers will swoop in and free the nation from the demagogue’s grip: legal systems simply aren’t designed for assaults of this magnitude.

(If, for example, you were designing the US Constitution, how would you guard against a presidential candidate who openly supported and was supported by a hostile foreign power, and won anyway? Would it even occur to you to include such possibilities in your definitions of concepts like “treason” or “collusion”?)

The original Zionist project—the secular, democratic vision of Herzl and Ben-Gurion and Weizmann and Einstein, which the Nazis turned from a dream to a necessity—matters more to me than most things in this world, and that was true even before I’d spent time in Israel and before I had a wife and kids who are Israeli citizens. It would be depressing if, after a century of wildly improbable victories against external threats, Herzl’s project were finally to eat itself from the inside. Of course I have analogous worries (scaled up by two orders of magnitude) for the US—not to mention the UK, India, Brazil, Poland, Hungary, the Philippines … the world is now engaged in a massive test of whether Enlightenment liberalism can long endure, or whether it’s just a metastable state between one Dark Age and the next. (And to think that people have accused me of uncritical agreement with Steven Pinker, the world’s foremost optimist!)

In times like this, one takes one’s happiness where one can find it.

So, yeah: I’m happy that there’s now an “image of a black hole” (or rather, of radio waves being bent around a black hole’s silhouette). If you really want to understand what the now-ubiquitous image is showing, I strongly recommend this guide by Matt Strassler.

I’m happy that integer multiplication can apparently now be done in O(n log n), capping a decades-long quest (see also here).

I’m happy that there’s now apparently a spectacular fossil record of the first minutes after the asteroid impact that ended the Cretaceous period. Even better will be if this finally proves that, yes, some non-avian dinosaurs were still alive on impact day, and had not gone extinct due to unrelated climate changes slightly earlier. (Last week, my 6-year-old daughter sang a song in a school play about how “no one knows what killed the dinosaurs”—the verses ran through the asteroid and several other possibilities. I wonder if they’ll retire that song next year.) If you haven’t yet read it, the New Yorker piece on this is a must.

I’m happy that my good friend Zach Weinersmith (legendary author of SMBC Comics), as well as the GMU economist Bryan Caplan (rabblerousing author of The Case Against Education, which I reviewed here), have a new book out: a graphic novel that makes a moral and practical case for open borders (!). Their book is now available for pre-order, and at least at some point cracked Amazon’s top 10. Just last week I met Bryan for the first time, when he visited UT Austin to give a talk based on the book. He said that meeting me (having known me only from the blog) was like meeting a fictional character; I said the feeling was mutual. And as for Bryan’s talk? It felt great to spend an hour visiting a fantasyland where the world’s economies are run by humane rationalist technocrats, and where walls are going down rather than up.

I’m happy that, according to this Vanity Fair article, Facebook will still ban you for writing that “men are scum” or that “women are scum”—having ultimately rejected the demands of social-justice activists that it ban only the latter sentence, not the former. According to the article, everyone on Facebook’s Community Standards committee agreed with the activists that this was the right result: dehumanizing comments about women have no place on the platform, while (superficially) dehumanizing comments about men are an important part of feminist consciousness-raising that require protection. The problem was simply that the committee couldn’t come up with any general principle that would yield that desired result, without also yielding bad results in other cases.

I’m happy that the 737 Max jets are grounded and will hopefully be fixed, with no thanks to the FAA. Strangely, while this was still the top news story, I gave a short talk about quantum computing to a group of Boeing executives who were visiting UT Austin on a previously scheduled trip. The title of the session they put me in? “Disruptive Computation.”

I’m happy that Greta Thunberg, the 15-year-old Swedish climate activist, has attracted a worldwide following and might win the Nobel Peace Prize. I hope she does—and more importantly, I hope her personal story will help galvanize the world into accepting things that it already knows are true, as with the example of Anne Frank (or for that matter, Gandhi or MLK). Confession: back when I was an adolescent, I often daydreamed about doing exactly what Thunberg is doing right now, leading a worldwide children’s climate movement. I didn’t, of course. In my defense, I wouldn’t have had the charisma for it anyway—and also, I got sidetracked by even more pressing problems, like working out the quantum query complexity of recursive Fourier sampling. But fate seems to have made an excellent choice in Thunberg. She’s not the prop of any adult—just a nerdy girl with Asperger’s who formed the idea to sit in front of Parliament every day to protest the destruction of the world, because she couldn’t understand why everyone else wasn’t.

I’m happy that the college admissions scandal has finally forced Americans to confront the farcical injustice of our current system—a system where elite colleges pretend to peer into applicants’ souls (or the souls of the essay consultants hired by the applicants’ parents?), and where they preen about the moral virtue of their “holistic, multidimensional” admissions criteria, which amount in practice to shutting out brilliant working-class Asian kids in favor of legacies and rich badminton players. Not to horn-toot, but Steven Pinker and I tried to raise the alarm about this travesty five years ago (see for example this post), and were both severely criticized for it. I do worry, though, that people will draw precisely the wrong lessons from the scandal. If, for example, a few rich parents resorted to outright cheating on the SAT—all their other forms of gaming and fraud apparently being insufficient—then the SAT itself must be to blame so we should get rid of it. In reality, the SAT (whatever its flaws) is almost the only bulwark we have against the complete collapse of college admissions offices into nightclub bouncers. This Quillette article says it much better than I can.

I’m happy that there will a symposium from May 6-9 at the University of Toronto, to honor Stephen Cook and the (approximate) 50^th anniversary of the discovery of NP-completeness. I’m happy that I’ll be attending and speaking there. If you’re interested, there’s still time to register!

Finally, I’m happy about the following “Sierpinskitaschen” baked by CS grad student and friend-of-the-blog Jess Sorrell, and included with her permission (Jess says she got the idea from Debs Gardner).

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Congrats to Geoffrey Hinton, Yann LeCun, and Yoshua Bengio, who won the 2018 Turing Award for their work on deep learning (i.e., what used to be called neural nets). This might be the first Turing Award ever given for something where no one really understands why it works … and it’s years overdue.

Congrats to Avi Wigderson for winning the Knuth Prize. When I was asked to write a supporting nomination letter, my first suggestion was to submit a blank sheet of paper—since for anyone in theoretical computer science, there’s nothing that needs to be said about why Avi should win any awards we have. I hope Avi remains a guiding light of our community for many years to come.

And congrats to Mark Braverman for winning the Alan T. Waterman Award, one that I have some personal fondness for, along with materials scientist Jennifer Dionne. As Sasha Razborov once put it, after he (Sasha), I, and others recoiled from the task of proving the Linial-Nisan Conjecture, that polylog-wise independent distributions are indistinguishable from uniform by AC⁰ circuits, a “braver man” stepped in to do the job.

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As most of you in theoretical computer science will know, the submission deadline for the 2019 FOCS conference is this Friday, April 5. The FOCS’2019 program committee chair, my UT Austin colleague David Zuckerman, has asked me to warn everyone that a fake submission site was set up at aconf.org—apparently as a phishing scam—and is one of the first results to come up when you google “FOCS 2019.” Do not submit there! The true URL is focs2019.cs.jhu.edu; accept no substitutes!

Anyway, I’ve been thrashing for several weeks—just barely escaping spaghettification at the Email Event Horizon—but I hope to be back shortly with your regularly scheduled programming.

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The purpose of this post is mostly just to signal-boost Konstantin Kakaes’s article in MIT Technology Review, entitled “No, scientists didn’t just ‘reverse time’ with a quantum computer.” The title pretty much says it all—but if you want more, you should read the piece, which includes the following droll quote from some guy calling himself “Director of the Quantum Information Center at the University of Texas at Austin”:

If you’re simulating a time-reversible process on your computer, then you can ‘reverse the direction of time’ by simply reversing the direction of your simulation. From a quick look at the paper, I confess that I didn’t understand how this becomes more profound if the simulation is being done on IBM’s quantum computer.

Incredibly, the time-reversal claim has now gotten uncritical attention in Newsweek, Discover, Cosmopolitan, my Facebook feed, and elsewhere—hence this blog post, which has basically no content except “the claim to have ‘reversed time,’ by running a simulation backwards, is exactly as true and as earth-shattering as a layperson might think it is.”

If there’s anything interesting here, I suppose it’s just that “scientists use a quantum computer to reverse time” is one of the purest examples I’ve ever seen of a scientific claim that basically amounts to a mind-virus or meme optimized for sharing on social media—discarding all nontrivial “science payload” as irrelevant to its propagation.

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Manolis Kellis is a computational biologist at MIT, known as one of the leaders in applying big data to genomics and gene regulatory networks. Throughout my 9 years at MIT, Manolis was one of my best friends there, even though our research styles and interests might seem distant. He and I were in the same PECASE class; see if you can spot us both in this photo (in the rows behind America’s last sentient president). My and Manolis’s families also became close after we both got married and had kids. We still keep in touch.

Today Manolis will be celebrating his 42nd birthday, with a symposium on the meaning of life (!). He asked his friends and colleagues to contribute talks and videos reflecting on that weighty topic.

Here’s a 15-minute video interview that Manolis and I recorded last night, where he asks me to pontificate about the implications of quantum mechanics for consciousness and free will and whether the universe is a computer simulation—and also about, uh, how to balance blogging with work and family.

Also, here’s a 2-minute birthday video that I made for Manolis before I really understood what he wanted. Unlike the first video, this one has no academic content, but it does involve me wearing a cowboy hat and swinging a makeshift “lasso.”

Happy birthday Manolis!

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In 1993, the science writer John Horgan—who’s best known for his book The End of Science, and (of course) for interviewing me in 2016—wrote a now-(in)famous cover article for Scientific American entitled “The Death of Proof.” Mashing together a large number of (what I’d consider) basically separate trends and ideas, Horgan argued that math was undergoing a fundamental change, with traditional deductive proofs being replaced by a combination of non-rigorous numerical simulations, machine-generated proofs, probabilistic and probabilistically-checkable proofs, and proofs using graphics and video. Horgan also suggested that Andrew Wiles’s then-brand-new proof of Fermat’s Last Theorem—which might have looked, at first glance, like a spectacular counterexample to the “death of proof” thesis—could be the “last gasp of a dying culture” and a “splendid anachronism.” Apparently, “The Death of Proof” garnered one of the largest volumes of angry mail in Scientific American‘s history, with mathematician after mathematician arguing that Horgan had strung together half-digested quotes and vignettes to manufacture a non-story.

Now Horgan—who you could variously describe as a wonderful sport, or a ham, or a sucker for punishment—has written a 26-year retrospective on his “death of proof” article. The prompt for this was Horgan’s recent discovery that, back in the 90s, David Hoffman and Hermann Karcher, two mathematicians annoyed by the “death of proof” article, had named a nonexistent mathematical object after its author. The so-called Horgan surface is a minimal surface that numerical computations strongly suggested should exist, but that can be rigorously proven not to exist after all. “The term was intended as an insult, but I’m honored anyway,” Horgan writes.

As a followup to his blog post, Horgan then decided to solicit commentary from various people he knew, including yours truly, about “how proofs are faring in an era of increasing computerization.” He wrote, “I’d love to get a paragraph or two from you.” Alas, I didn’t have the time to do as requested, but only to write eight paragraphs. So Horgan suggested that I make the result into a post on my own blog, which he’d then link to. Without further ado, then:

John, I like you so I hate to say it, but the last quarter century has not been kind to your thesis about “the death of proof”!  Those mathematicians sending you the irate letters had a point: there’s been no fundamental change to mathematics that deserves such a dramatic title.  Proof-based math remains quite healthy, with (e.g.) a solution to the Poincaré conjecture since your article came out, as well as to the Erdős discrepancy problem, the Kadison-Singer conjecture, Catalan’s conjecture, bounded gaps in primes, testing primality in deterministic polynomial time, etc. — just to pick a few examples from the tiny subset of areas that I know anything about.

There are evolutionary changes to mathematical practice, as there always have been.  Since 2009, the website MathOverflow has let mathematicians query the global hive-mind about an obscure reference or a recalcitrant step in a proof, and get near-instant answers.  Meanwhile “polymath” projects have, with moderate success, tried to harness blogs and other social media to make advances on long-standing open math problems using massive collaborations.

While humans remain in the driver’s seat, there are persistent efforts to increase the role of computers, with some notable successes.  These include Thomas Hales’s 1998 computer-assisted proof of the Kepler Conjecture (about the densest possible way to pack oranges) — now fully machine-verified from start to finish, after the Annals of Mathematics refused to publish a mixture of traditional mathematics and computer code (seems this is not exactly what happened; see the comment section for more).  It also includes William McCune’s 1996 solution to the Robbins Conjecture in algebra (the computer-generated proof was only half a page, but involved substitutions so strange that for 60 years no human had found them); and at the “opposite extreme,” the 2016 solution to the Pythagorean triples problem by Marijn Heule and collaborators, which weighed in at 200 terabytes (at that time, “the longest proof in the history of mathematics”).

It’s conceivable that someday, computers will replace humans at all aspects of mathematical research — but it’s also conceivable that, by the time they can do that, they’ll be able to replace humans at music and science journalism and everything else!

New notions of proof — including probabilistic, interactive, zero-knowledge, and even quantum proofs — have seen further development by theoretical computer scientists since 1993.  So far, though, these new types of proof remain either entirely theoretical (as with quantum proofs), or else they’re used for cryptographic protocols but not for mathematical research.  (For example, zero-knowledge proofs now play a major role in certain cryptocurrencies, such as Zcash.)

In many areas of math (including my own, theoretical computer science), proofs have continued to get longer and harder for any one person to absorb.  This has led some to advocate a split approach, wherein human mathematicians would talk to each other only about the handwavy intuitions and high-level concepts, while the tedious verification of details would be left to computers.  So far, though, the huge investment of time needed to write proofs in machine-checkable format — for almost no return in new insight — has prevented this approach’s wide adoption.

Yes, there are non-rigorous approaches to math, which continue to be widely used in physics and engineering and other fields, as they always have been.  But none of these approaches have displaced proof as the gold standard whenever it’s available.  If I had to speculate about why, I’d say: if you use non-rigorous approaches, then even if it’s clear to you under what conditions your results can be trusted, it’s probably much less clear to others.  Also, even if only one segment of a research community cares about rigor, whatever earlier work that segment builds on will need to be rigorous as well — thereby exerting constant pressure in that direction.  Thus, the more collaborative a given research area becomes, the more important is rigor.

For my money, the elucidation of the foundations of mathematics a century ago, by Cantor, Frege, Peano, Hilbert, Russell, Zermelo, Gödel, Turing, and others, still stands as one of the greatest triumphs of human thought, up there with evolution or quantum mechanics or anything else.  It’s true that the ideal set by these luminaries remains mostly aspirational.  When mathematicians say that a theorem has been “proved,” they still mean, as they always have, something more like: “we’ve reached a social consensus that all the ideas are now in place for a strictly formal proof that could be verified by a machine … with the only task remaining being massive rote coding work that none of us has any intention of ever doing!”  It’s also true that mathematicians, being human, are subject to the full panoply of foibles you might expect: claiming to have proved things they haven’t, squabbling over who proved what, accusing others of lack of rigor while hypocritically taking liberties themselves.  But just like love and honesty remain fine ideals no matter how often they’re flouted, so too does mathematical rigor.

Update: Here’s Horgan’s new post (entitled “Okay, Maybe Proofs Aren’t Dying After All”), which also includes a contribution from Peter Woit.

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If I’m being honest, the most exciting recent development in my life is this: a little over a month ago, I stopped checking “SneerClub” (a place I’d previously resolved not even to name here, but I think an exception is warranted now). Permanently, cold turkey. I won’t even visit to read their sneers about this post. I’ve made progress cutting down on other self-destructive social media fixations as well. Many friends suggested this course to me, and I thank them all, though I ultimately had to follow my own path to the obvious.

Ironically, the SneerClubbers themselves begged me to stop reading them (!), so presumably for once they’ll be okay with something I did (but if not, I don’t care). If any of them still have something to say to me, they can come to this blog, or email me, or if they pass through Austin, set up a time to hash it out over chips and queso (my treat). What I’ll no longer do is spend hours every week binge-reading a forum of people who’ve adopted nastiness and bad faith as their explicit principles. I’ll no longer toss and turn at night wondering how it came about that two thousand Redditors hate Scott Aaronson so much, and what I could say or do (short of total self-abnegation) that would make them hate me less. I plan to spend the freed-up time being Scott Aaronson.

Resolving to ignore one particular online hate pit—and then sticking to the resolution, as so far I have—has been a pure, unmitigated improvement to my quality of life. If you don’t believe me, ask my wife and kids. I recommend this course to anyone.

You could sensibly ask: why did I ever spend time worrying about an anti-nerds-like-me forum that’s so poisonous for its targets and participants alike? After long introspection, I think the answer is: there’s a part of me, perhaps a gift from the childhood bullies, that’s so obsessed with “society’s hatred of STEM nerds,” that it constantly seeks out evidence to confirm that its fears are justified—evidence that it can then wave in front of the rest of my brain to say “you see?? what did I always tell you?” And alas, whenever that part of my brain seeks such evidence, the world dutifully supplies mountains of it. It’s never once disappointed.

Now the SneerClubbers—who are perceptive and talented in their cruelty, if in nothing else—notice this about me, and gleefully ridicule me for it. But they’re oblivious to the central irony: that unlike the vast majority of humankind, or even the vast majority of social justice activists, they (the SneerClubbers) really do hate everyone like me. They’re precisely what the paranoid part of my brain wrongly fears that everyone else I meet is secretly like. They’re like someone who lectures you about your hilariously overblown fear of muggers, while simultaneously mugging you.

But at least they’re not the contented and self-confident bullies of my childhood nightmares, kicking dirt down at nerds from atop their pinnacle of wokeness and social adeptness. If you spend enough time studying them, they themselves come across as angry, depressed, pathetic. So for example: here’s one of my most persistent attackers, popping up on a math thread commemorating Michael Atiyah (one of the great mathematicians of the 20th century), just to insult Atiyah—randomly, gratuitously, and a few days after Atiyah had died. Almost everything posted all over Reddit by this individual—who uses the accurate tagline “unpleasantly radical”—has the same flavor. Somehow seeing this made it click for me: wait a second, these are the folks are lecturing me about my self-centeredness and arrogance and terrible social skills? Like, at least I try to be nice.

Scott Alexander, who writes the world’s best blog and is a more central target of SneerClub than I’ve been, recently announced that he asked the moderators of r/ssc to close its notorious “Culture War” thread, and they’ve done so—moving the thread to a new home on Reddit called “TheMotte.”

For those who don’t know: r/ssc is the place on Reddit to discuss Scott’s SlateStarCodex blog, though Scott himself was never too involved as more than a figurehead.  The Culture War thread was the place within r/ssc to discuss race, gender, immigration, and other hot-button topics.  The thread, which filled up with a bewildering thousands of comments per week (!), attracted the, err … full range of political views, including leftists, libertarians, and moderates but also alt-righters, neoreactionaries, and white nationalists. Predictably, SneerClub treated the thread as a gift from heaven: a constant source of inflammatory material that they could use to smear Scott personally (even if most of the time, Scott hadn’t even seen the offending content, let alone endorsing it).

Four months ago, I was one of the apparently many friends who told Scott that I felt he should dissociate the Culture War thread from his brand. So I congratulate him on his decision, which (despite his eloquently-expressed misgivings) I feel confident was the right one. Think about it this way: nobody’s freedom of speech has been curtailed—the thread continues full steam at TheMotte, for anyone who enjoys it—but meanwhile, the sneerers have been deprived of a golden weapon with which to slime Scott. Meanwhile, while the sneerers themselves might never change their minds about anything, Scott has demonstrated to third parties that he’s open and reasonable and ready to compromise, like the debater who happily switches to his opponent’s terminology. What’s not to like?

A couple weeks ago, while in Albuquerque for the SQuInT conference, I visited the excellent National Museum of Nuclear Science and History.  It was depressing, as it should have been, to tour the detailed exhibits about the murderous events surrounding the birth of the nuclear era: the Holocaust, the Rape of Nanking, the bombings of Hiroshima and Nagasaki. It was depressing in a different way to tour the exhibits about the early Atomic Age, and see the boundless optimism that ‘unleashing the power of the atom’ would finally usher in a near-utopia of space travel and clean energy—and then to compare that vision to where we are now, with climate change ravaging the planet and (in a world-historic irony) the people who care most about the environment having denounced and marginalized the most reliable source of carbon-free energy, the one that probably had the best chance to avert our planet’s terrifying future.

But on the bright side: how wonderful to have born into a time and place when, for the most part, those who hate you have only the power to destroy your life that you yourself grant them. How wonderful when one can blunt their knives by simply refusing to open a browser tab.

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A few weeks ago, I was at QIP’2019 in Boulder, CO. This week I was at SQuInT’2019 in Albuquerque, NM. There were lots of amazing talks—feel free to ask in the comments section.

There’s an interview with me at the website “GigaOm,” conducted by Byron Reese and entitled Quantum Computing: Capabilities and Limits. I didn’t proofread the transcript and it has some errors in it, but hopefully the meaning comes through. In other interview news, if you were interested in my podcast with Adam Ford in Melbourne but don’t like YouTube, Adam has helpfully prepared transcripts of the two longest segments: The Ghost in the Quantum Turing Machine and The Winding Road to Quantum Supremacy.

The New York Times ran an article entitled The Hard Part of Computer Science? Getting Into Class, about the surge in computer science majors all over the US, and the shortage of professors to teach them. The article’s go-to example of a university where this is happening is UT Austin, and there’s extensive commentary from my department chair, Don Fussell.

The STOC’2019 accepted papers list is finally out. Lots of cool stuff!

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I’ve of course been following the recent public debate about whether to build a circular collider to succeed the LHC—notably including Sabine Hossenfelder’s New York Times column arguing that we shouldn’t.  (See also the responses by Jeremy Bernstein and Lisa Randall, and the discussion on Peter Woit’s blog, and Daniel Harlow’s Facebook thread, and this Vox piece by Kelsey Piper.)  Let me blog about this as a way of cracking my knuckles or tuning my violin, just getting back into blog-shape after a long hiatus for travel and family and the beginning of the semester.

Regardless of whether this opinion is widely shared among my colleagues, I like Sabine.  I’ve often found her blogging funny and insightful, and I wish more non-Lubos physicists would articulate their thoughts for the public the way she does, rather than just standing on the sidelines and criticizing the ones who do. I find it unfortunate that some of the replies to Sabine’s arguments dwelled on her competence and “standing” in physics (even if we set aside—as we should—Lubos’s misogynistic rants, whose predictability could be used to calibrate atomic clocks). It’s like this: if high-energy physics had reached a pathological state of building bigger and bigger colliders for no good reason, then we’d expect that it would take a semi-outsider to say so in public, so then it wouldn’t be a further surprise to find precisely such a person doing it.

Not for the first time, though, I find myself coming down on the opposite side as Sabine. Basically, if civilization could get its act together and find the money, I think it would be pretty awesome to build a new collider to push forward the energy frontier in our understanding of the universe.

Note that I’m not making the much stronger claim that this is the best possible use of $20 billion for science. Plausibly a thousand $20-million projects could be found that would advance our understanding of reality by more than a new collider would. But it’s also important to realize that that’s not the question at stake here. When, for example, the US Congress cancelled the Superconducting Supercollider midway through construction—partly, it’s believed, on the basis of opposition from eminent physicists in other subfields, who argued that they could do equally important science for much cheaper—none of the SSC budget, as in 0% of it, ever did end up redirected to those other subfields. In practice, then, the question of “whether a new collider is worth it” is probably best considered in absolute terms, rather than relative to other science projects.

What I found most puzzling, in Sabine’s writings on this subject, was the leap in logic from

1. many theorists expected that superpartners, or other new particles besides the Higgs boson, had a good chance of being discovered at the LHC, based on statistical arguments about “natural” parameter values, and
2. the basic soundness of naturalness arguments was always open to doubt, and indeed the LHC results to date offer zero support for them, and
3. many of the same theorists now want an even bigger collider, and continue to expect new particles to be found, and haven’t sufficiently reckoned with their previous failed predictions, to …
4. therefore we shouldn’t build the bigger collider.

How do we get from 1-3 to 4: is the idea that we should punish the errant theorists, by withholding an experiment that they want, in order to deter future wrong predictions? After step 3, it seems to me that Sabine could equally well have gone to: and therefore it’s all the more important that we do build a new collider, in order to establish all the more conclusively that there’s just an energy desert up there—and that I, Sabine, was right to emphasize that possibility, and those other theorists were wrong to downplay it!

Like, I gather that there are independently motivated scenarios where there would be only the Higgs at the LHC scale, and then new stuff at the next energy scale beyond it. And as an unqualified outsider who enjoys talking to friends in particle physics and binge-reading about it, I’d find it hard to assign the totality of those scenarios less than ~20% credence or more than ~80%—certainly if the actual experts don’t either.

And crucially, it’s not as if raising the collision energy is just one arbitrary direction in which to look for new fundamental physics, among a hundred a-priori equally promising directions. Basically, there’s raising the collision energy and then there’s everything else. By raising the energy, you’re not testing one specific idea for physics beyond Standard Model, but a hundred or a thousand ideas in one swoop.

The situation reminds me a little of the quantum computing skeptics who say: scalable QC can never work, in practice and probably even in principle; the mainstream physics community only thinks it can work because of groupthink and hype; therefore, we shouldn’t waste more funds trying to make it work. With the sole, very interesting exception of Gil Kalai, none of the skeptics ever seem to draw what strikes me as an equally logical conclusion: whoa, let’s go full speed ahead with trying to build a scalable QC, because there’s an epochal revolution in physics to be had here—once the experimenters finally see that I was right and the mainstream was wrong, and they start to unravel the reasons why!

Of course, $20 billion is a significant chunk of change, by the standards of science even if not by the standards of random government wastages (like our recent $11 billion shutdown). And ultimately, decisions do need to be made about which experiments are most interesting to pursue with limited resources. And if a future circular collider were built, and if it indeed just found a desert, I think the balance would tilt pretty strongly toward Sabine’s position—that is, toward declining to build an even bigger and more expensive collider after that. If the Patriots drearily won every Superbowl 13-3, year after year after year, eventually no one would watch anymore and the Superbowl would get cancelled (well, maybe that will happen for other reasons…).

But it’s worth remembering that—correct me if I’m wrong—so far there have been no cases in the history of particle physics of massively expanding the energy frontier and finding absolutely nothing new there (i.e., nothing that at least conveyed multiple bits of information, as the Higgs mass did). And while my opinion should count for less than a neutrino mass, just thinking it over a-priori, I keep coming back to the question: before we close the energy frontier for good, shouldn’t there have been at least one unmitigated null result, rather than zero?

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Greetings from QIP’2019 in Boulder, Colorado! Obvious highlights of the conference include Urmila Mahadev’s opening plenary talk on her verification protocol for quantum computation (which I blogged about here), and Avishay Tal’s upcoming plenary on his and Ran Raz’s oracle separation between BQP and PH (which I blogged about here). If you care, here are the slides for the talk I just gave, on the paper “Online Learning of Quantum States” by me, Xinyi Chen, Elad Hazan, Satyen Kale, and Ashwin Nayak. Feel free to ask in the comments about what else is going on.

I returned a few days ago from my whirlwind Australia tour, which included Melbourne and Sydney; a Persian wedding that happened to be held next to a pirate ship (the Steve Irwin, used to harass whalers and adorned with a huge Jolly Roger); meetings and lectures graciously arranged by friends at UTS; a quantum computing lab tour personally conducted by 2018 “Australian of the Year” Michelle Simmons; three meetups with readers of this blog (or more often, readers of the other Scott A’s blog who graciously settled for the discount Scott A); and an excursion to Grampians National Park to see wild kangaroos, wallabies, koalas, and emus.

But the thing that happened in Australia that provided the actual occassion for this post is this: I was interviewed by Adam Ford in Carlton Gardens in Melbourne, about quantum supremacy, AI risk, Integrated Information Theory, whether the universe is discrete or continuous, and to be honest I don’t remember what else. You can watch the first segment, the one about the prospects for quantum supremacy, here on YouTube. My only complaint is that Adam’s video camera somehow made me look like an out-of-shape slob who needs to hit the gym or something.

Update (Jan. 16): Adam has now posted a second video on YouTube, wherein I talk about my “Ghost in the Quantum Turing Machine” paper, my critique of Integrated Information Theory, and more.

And now Adam has posted yet a third segment, in which I talk about small, lighthearted things like existential threats to civilization and the prospects for superintelligent AI.

And a fourth, in which I talk about whether reality is discrete or continuous.

Related to the “free will / consciousness” segment of the interview: the biologist Jerry Coyne, whose blog “Why Evolution Is True” I’ve intermittently enjoyed over the years, yesterday announced my existence to his readers, with a post that mostly criticizes my views about free will and predictability, as I expressed them years ago in a clip that’s on YouTube (at the time, Coyne hadn’t seen GIQTM or my other writings on the subject). Coyne also took the opportunity to poke fun at this weird character he just came across whose “life is devoted to computing” and who even mistakes tips for change at airport smoothie stands. Some friends here at QIP had a good laugh over the fact that, for the world beyond theoretical computer science and quantum information, this is what 23 years of research, teaching, and writing apparently boil down to: an 8.5-minute video clip where I spouted about free will, and also my having been arrested once in a comic mix-up at Philadelphia airport. Anyway, since then I had a very pleasant email exchange with Coyne—someone with whom I find myself in agreement much more often than not, and who I’d love to have an extended conversation with sometime despite the odd way our interaction started.

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