Scott Aaronson's Blog

Last week, I gave the Patrick Suppes Lecture in the Columbia University Philosophy Department. Patrick Suppes was a distinguished philosopher at Stanford who (among many other things) pioneered remote gifted education through the EPGY program, and who I was privileged to spend some time with back in 2007, when he was in his eighties.

My talk at Columbia was entitled “Computational Complexity and Explanations in Physics.” Here are the PowerPoint slides, and here’s the abstract:

The fact, or conjecture, of certain computational problems being intractable (that is, needing astronomical amounts of time to solve) clearly affects our ability to learn about physics.  But could computational intractability also play a direct role in physical explanations themselves?  I’ll consider this question by examining three possibilities:

(1) If quantum computers really take exponential time to simulate using classical computers, does that militate toward the many-worlds interpretation of quantum mechanics, as David Deutsch famously proposed?

(2) Are certain speculative physical ideas (e.g., time travel to the past or nonlinearities in quantum mechanics) disfavored, over and above any other reasons to disfavor them, because they would lead to “absurd computational superpowers”?

(3) Do certain effective descriptions in physics work only because of the computational intractability of violating those descriptions — as for example with Harlow and Hayden’s resolution of the “firewall paradox” in black hole thermodynamics, or perhaps even the Second Law of Thermodynamics itself?

I’m grateful to David Albert and Lydia Goehr of Columbia’s Philosophy Department, who invited me and organized the talk, as well as string theorist Brian Greene, who came and contributed to the discussion afterward. I also spent a day in Columbia’s CS department, gave a talk about my recent results on quantum oracles, and saw many new friends and old there, including my and my wife’s amazing former student Henry Yuen. Thanks to everyone.

This was my first visit to Columbia University for more than a decade, and certainly my first since the upheavals following the October 7 massacre. Of course I was eager to see the situation for myself, having written about it on this blog. Basically, if you’re a visitor like me, you now need both a QR code and an ID to get into the campus, which is undeniably annoying. On the other hand, once you’re in, everything is pleasant and beautiful. Just from wandering around, I’d have no idea that this campus had recently been Ground Zero for the pro-intifada protests, and then for the reactions against those protests (indeed, the use of the protests as a pretext to try to destroy academia entirely) that rocked the entire country, filling my world and my social media feed.

When I asked friends and colleagues about the situation, I heard a range of perspectives: some were clearly exasperated with the security measures; others, while sharing in the annoyance, suggested the measures seem to be needed, since every time the university has tried to relax them, the “intifada” has returned, with non-university agitators once again disrupting research and teaching. Of course we can all pray that the current ceasefire will hold, for many reasons, the least of which is that perhaps then the obsession of the world’s young and virtuous to destroy the world’s only Jewish state will cool down a bit, and they’ll find another target for their rage. That would also help life at Columbia and other universities return to how it was before.

Before anyone asks: no, Columbia’s Peter Woit never showed up to disrupt my talk with rotten vegetables or a bullhorn—indeed, I didn’t see him at all on his trip, nor did I seek him out. Given that Peter chose to use his platform, one of the world’s best-known science blogs, to call me a mentally ill genocidal fascist week after week, it meant an enormous amount to me to see how many friends and supporters I have right in his own backyard.

All in all, I had a wonderful time at Columbia, and based on what I saw, I won’t hesitate to come back, nor will I hesitate to recommend Jewish or Israeli or pro-Zionist students to study there.

Today, of course, is the second anniversary of the genocidal Oct. 7 invasion of Israel—the deadliest day for Jews since the Holocaust, and the event that launched the current wars that have been reshaping the Middle East for better and/or worse. Regardless of whether their primary concern is for Israelis, Palestinians, or both, I’d hope all readers of this blog could at least join me in wishing this barbaric invasion had never happened, and in condemning the celebrations of it taking place around the world.

Now for the happy part: today is also the day when the Nobel Prize in Physics is announced. I was delighted to wake up to the news that this year, the prize goes to John Clarke of Berkeley, John Martinis of UC Santa Barbara, and Michel Devoret of Yale, for their experiments in the 1980s that demonstrated the reality of macroscopic quantum tunneling in superconducting circuits. Among other things, this work laid the foundation for the current effort by Google, IBM, and many others to build quantum computers with superconducting qubits. To clarify, though, today’s prize is not for quantum computing per se, but for the earlier work.

While I don’t know John Clarke, and know Michel Devoret only a little, I’ve been proud to count John Martinis as a good friend for the past decade—indeed, his name has often appeared on this blog. When Google hired John in 2014 to build the first programmable quantum computer capable of demonstrating quantum supremacy, it was clear that we’d need to talk about the theory, so we did. Through many email exchanges, calls, and visits to Google’s Santa Barbara Lab, I came to admire John for his iconoclasm, his bluntness, and his determination to make sampling-based quantum supremacy happen. After Google’s success in 2019, I sometimes wondered whether John might eventually be part of a Nobel Prize in Physics for his experimental work in quantum computing. That may have become less likely today, now that he’s won the Nobel Prize in Physics for his work before quantum computing, but I’m guessing he doesn’t mind! Anyway, huge congratulations to all three of the winners.

A couple days ago, Freek Witteveen of CWI and I posted a paper to the arXiv called “Limits to black-box amplification in QMA.” Let me share the abstract:

We study the limitations of black-box amplification in the quantum complexity class QMA. Amplification is known to boost any inverse-polynomial gap between completeness and soundness to exponentially small error, and a recent result (Jeffery and Witteveen, 2025) shows that completeness can in fact be amplified to be doubly exponentially close to 1. We prove that this is optimal for black-box procedures: we provide a quantum oracle relative to which no QMA verification procedure using polynomial resources can achieve completeness closer to 1 than doubly exponential, or a soundness which is super-exponentially small. This is proven by using techniques from complex approximation theory, to make the oracle separation from (Aaronson, 2008), between QMA and QMA with perfect completeness, quantitative.

You can also check out my PowerPoint slides here.

To explain the context: QMA, or Quantum Merlin Arthur, is the canonical quantum version of NP. It’s the class of all decision problems for which, if the answer is “yes,” then Merlin can send Arthur a quantum witness state that causes him to accept with probability at least 2/3 (after a polynomial-time quantum computation), while if the answer is “no,” then regardless of what witness Merlin sends, Arthur accepts with probability at most 1/3. Here, as usual in complexity theory, the constants 2/3 and 1/3 are just conventions, which can be replaced (for example) by 1-2-n and 2-n using amplification.

A longstanding open problem about QMA—not the biggest problem, but arguably the most annoying—has been whether the 2/3 can be replaced by 1, as it can be for classical MA for example. In other words, does QMA = QMA1, where QMA1 is the subclass of QMA that admits protocols with “perfect completeness”? In 2008, I used real analysis to show that there’s a quantum oracle relative to which QMA ≠ QMA1, which means that any proof of QMA = QMA1 would need to use “quantumly nonrelativizing techniques” (not at all an insuperable barrier, but at least we learned something about why the problem is nontrivial).

Then came a bombshell: in June, Freek Witteveen and longtime friend-of-the-blog Stacey Jeffery pOates a paper showing that any QMA protocol can be amplified, in a black-box manner, to have completeness error that’s doubly exponentially small, 1/exp(exp(n)). They did this via a method I never would’ve thought of, wherein a probability of acceptance is encoded via the amplitudes of a quantum state that decrease in a geometric series. QMA, it turned out, was an old friend that still had surprises up its sleeve after a quarter-century.

In August, we had Freek speak about this breakthrough by Zoom in our quantum group meeting at UT Austin. Later that day, I asked Freek whether their new protocol was the best you could hope to do with black-box techniques, or whether for example one could amplify the completeness error to be triply exponentially small, 1/exp(exp(exp(n))). About a week later, Freek and I had a full proof written down that, using black-box techniques, doubly-exponentially small completeness error is the best you can do. In other words: we showed that, when one makes my 2008 QMA ≠ QMA1 quantum oracle separation quantitative, one gets a lower bound that precisely matches Freek and Stacey’s protocol.

All this will, I hope, interest and excite aficianados of quantum complexity classes, while others might have very little reason to care.

But here’s a reason why other people might care. This is the first paper I’ve ever put out for which a key technical step in the proof of the main result came from AI—specifically, from GPT5-Thinking. Here was the situation: we had an N×N Hermitian matrix E(θ) (where, say, N=2n), each of whose entries was a poly(n)-degree trigonometric polynomial in a real parameter θ. We needed to study the largest eigenvalue of E(θ), as θ varied from 0 to 1, to show that this λmax(E(θ)) couldn’t start out close to 0 but then spend a long time “hanging out” ridiculously close to 1, like 1/exp(exp(exp(n))) close for example.

Given a week or two to try out ideas and search the literature, I’m pretty sure that Freek and I could’ve solved this problem ourselves. Instead, though, I simply asked GPT5-Thinking. After five minutes, it gave me something confident, plausible-looking, and (I could tell) wrong. But rather than laughing at the silly AI like a skeptic might do, I told GPT5 how I knew it was wrong. It thought some more, apologized, and tried again, and gave me something better. So it went for a few iterations, like interacting with a grad student. Within a half hour, it had told me to look at the function

$$ Tr[(I-E(\theta))^{-1}] = \sum_{i=1}^N \frac{1}{1-\lambda_i(\theta)}. $$

It pointed out, correctly, that this was a rational function in θ of controllable degree, that happened to encode the relevant information about how close the largest eigenvalue λmax(E(θ)) is to 1. And this … worked, as we were able to check ourselves with no AI assistance! And I mean, maybe GPT5 had seen this or a similar construction somewhere in its training data. But there’s not the slightest doubt that, if a student had given it to me, I would’ve called it clever and creative.

I had tried similar problems a year ago, with the then-new GPT reasoning models, but I didn’t get results that were nearly as good. Now, in September 2025, I’m here to tell you that AI has finally come for what my experience tells me is the most quintessentially human of all human intellectual activities: namely, proving oracle separations between quantum complexity classes. Right now, it almost certainly can’t write the whole research paper (at least if you want it to be correct and good), but it can help a lot if you know what you’re doing, which you might call a sweet spot. Who knows how long this state of affairs will last? I guess it’s good that I have tenure.

Today, I got email after email asking me to comment on a new paper from HSBC—yes, the bank—together with IBM. The paper claims to use a quantum computer to get a 34% advantage in predictions of trading data. (See also blog posts here and here, or numerous popular articles that you can easily find and I won’t link.) What have we got? Let’s read the abstract:

The estimation of fill probabilities for trade orders represents a key ingredient in the optimization of algorithmic trading strategies. It is bound by the complex dynamics of financial markets with inherent uncertainties, and the limitations of models aiming to learn from multivariate financial time series that often exhibit stochastic properties with hidden temporal patterns. In this paper, we focus on algorithmic responses to trade inquiries in the corporate bond market and investigate fill probability estimation errors of common machine learning models when given real production-scale intraday trade event data, transformed by a quantum algorithm running on IBM Heron processors, as well as on noiseless quantum simulators for comparison. We introduce a framework to embed these quantum-generated data transforms as a decoupled offline component that can be selectively queried by models in lowlatency institutional trade optimization settings. A trade execution backtesting method is employed to evaluate the fill prediction performance of these models in relation to their input data. We observe a relative gain of up to ∼ 34% in out-of-sample test scores for those models with access to quantum hardware-transformed data over those using the original trading data or transforms by noiseless quantum simulation. These empirical results suggest that the inherent noise in current quantum hardware contributes to this effect and motivates further studies. Our work demonstrates the emerging potential of quantum computing as a complementary explorative tool in quantitative finance and encourages applied industry research towards practical applications in trading.

As they say, there are more red flags here than in a People’s Liberation Army parade. To critique this paper is not quite “shooting fish in a barrel,” because the fish are already dead before we’ve reached the end of the abstract.

They see a quantum advantage for the task in question, but only because of the noise in their quantum hardware? When they simulate the noiseless quantum computation classically, the advantage disappears? WTF? This strikes me as all but an admission that the “advantage” is just a strange artifact of the particular methods that they decided to compare—that it has nothing really to do with quantum mechanics in general, or with quantum computational speedup in particular.

Indeed, the possibility of selection bias rears its head. How many times did someone do some totally unprincipled, stab-in-the-dark comparison of a specific quantum learning method against a specific classical method, and get predictions from the quantum method that were worse than whatever they got classically … so then not publish a paper about it?

If it seems like I’m being harsh, it’s because to my mind, the entire concept of this sort of study is fatally flawed from the beginning, optimized for generating headlines rather than knowledge.  The first task, I would’ve thought, is to show the reality of quantum computational advantage in the system or algorithm being studied, even just for a useless benchmark task. Only after one has done that, has one earned the right to look for a practical benefit in algorithmic trading or predicting financial time-series data or whatever. If you skip the first step, then whatever “benefits” you find from QC are overwhelmingly likely to be cargo cult benefits.

And yet none of it matters. The paper can, more or less, openly admit all this right in the abstract, and yet it will still predictably generate lots of credulous popular articles about HSBC using quantum computers to improve bond trading—which, one assumes, was the whole point. Qombies roam the earth: undead narratives of “quantum advantage for important business problems” detached from any underlying truth-claim. And even here at one of the top 50 quantum computing blogs on the planet, there’s nothing I can do about it other than scream into the void.

From 2016 until last week, as the Trump movement dismantled one after another of the obvious bipartisan norms of the United States that I’d taken for granted since my childhood—e.g., the loser conceding an election and attending the winner’s inauguration, America being proudly a nation of immigrants, science being good, vaccines being good, Russia invading its neighbors being bad, corruption (when it occurred) not openly boasted about—I often consoled myself that at least the First Amendment, the motor of our whole system since 1791, was still in effect. At least you could still call Trump a thug and a conman without fear. Yes, Trump constantly railed against hostile journalists and comedians and protesters, threatened them at his rallies, filed frivolous lawsuits against them, but none of it seemed to lead to any serious program to shut them down. Oceans of anti-Trump content remained a click away.

I even wondered whether this was Trump’s central innovation in the annals of authoritarianism: proving that, in the age of streaming and podcasts and social media, you no longer needed to bother with censorship in order to build a regime of lies. You could simply ensure that the truth remained one narrative among others, that it never penetrated the epistemic bubble of your core supporters, who’d continue to be algorithmically fed whatever most flattered their prejudices.

Last week, that all changed. Another pillar of the previous world fell. According to the new norm, if you’re a late-night comedian who says anything Trump doesn’t like, he’ll have the FCC threaten your station’s affiliates’ broadcast licenses, and they’ll cave, and you’ll be off the air, and he’ll gloat about it. We ought to be clear that, even conditioned on everything else, this is a huge further step toward how things work in Erdogan’s Turkey or Orban’s Hungary, and how they were never supposed to work in America.

At risk of stating the obvious:

I was horrified by the murder of Charlie Kirk. Political murder burns our societal commons and makes the world worse in every way. I’d barely been aware of Kirk before the murder, but it seems clear he was someone with whom I’d have countless disagreements, but also some common ground, for example about Israel. Agree or disagree is beside the point, though. One thing we can all hopefully take from the example of Kirk’s short life, regardless of our beliefs, is his commitment to “Prove Me Wrong” and “Change My Mind”: to showing up on campus (or wherever people are likeliest to disagree with us) and exchanging words rather than bullets.
I’m horrified that there are fringe figures on social media who’ve celebrated Kirk’s murder or made light of it. I’m fine with such people losing their jobs, as I’d be with those who celebrate any political murder.
It looks like Kirk’s murderer was a vaguely left-wing lunatic, with emphasis on the “lunatic” part (as often with these assassins, his worldview wasn’t particularly coherent). Jimmy Kimmel was wrong to insinuate that the murderer was a MAGA conservative. But he was “merely” wrong. By no stretch of the imagination did Kimmel justify or celebrate Kirk’s murder.
If the new rule is that anyone who spreads misinformation gets cancelled by force of government, then certainly Fox News, One America News, Joe Rogan, and MAGA’s other organs of support should all go dark immediately.
Yes, I’m aware (to put it mildly) that, especially between 2015 and 2020, the left often used its power in media, academia, and nonprofits to try to silence those with whom it disagreed, by publicly shaming them and getting them blacklisted and fired. That was terrible too. I opposed it at the time, and in the comment-171 affair, I even risked my career to stand up to it.
But censorship backed by the machinery of state is even worse than social-media shaming mobs. As I and many others discovered back then, to our surprised relief, there are severe limits to the practical power of angry leftists on Twitter and Reddit. That was true then, and it’s even truer today. But there are far fewer limits to the power of a government, especially one that’s been reorganized on the principle of obedience to one man’s will. The point here goes far beyond “two wrongs don’t make a right.” As pointed out by that bleeding-heart woke, Texas Senator Ted Cruz, new weapons are being introduced that the other side will also be tempted to use when it retakes power. The First Amendment now has a knife to its throat, as it didn’t even at the height of the 2015-2020 moral panic.
Yes, five years ago, the federal government pressured Facebook and other social media platforms to take down COVID ‘misinformation,’ some of which turned out not to be misinformation at all. That was also bad, and indeed it dramatically backfired. But let’s come out and say it: censoring medical misinformation because you’re desperately trying to save lives during a global pandemic is a hundred times more forgivable than censoring comedians because they made fun of you. And no one can deny that the latter is the actual issue here, because Trump and his henchmen keep saying the quiet part out loud.

Anyway, I keep hoping that my next post will be about quantum complexity theory or AI alignment or Busy Beaver 6 or whatever. Whenever I feel backed into a corner, however, I will risk my career, and the Internet’s wrath, to blog my nutty, extreme, embarrassing, totally anodyne liberal beliefs that half or more of Americans actually share.

I’m thrilled that our paper entitled Demonstrating an unconditional separation between quantum and classical information resources, based on a collaboration between UT Austin and Quantinuum, is finally up on the arXiv. I’m equally thrilled that my coauthor and former PhD student William Kretschmer — who led the theory for this project, and even wrote much of the code — is now my faculty colleague at UT Austin! My physics colleague Nick Hunter-Jones and my current PhD student Sabee Grewal made important contributions as well. I’d especially like to thank the team at Quantinuum for recognizing a unique opportunity to test and showcase their cutting-edge hardware, and collaborating with us wild-eyed theorists to make it happen. This is something that, crucially, would not have been feasible with the quantum computing hardware of only a couple years ago.

Here’s our abstract, which I think explains what we did clearly enough, although do read the paper for more:

A longstanding goal in quantum information science is to demonstrate quantum computations that cannot be feasibly reproduced on a classical computer. Such demonstrations mark major milestones: they showcase fine control over quantum systems and are prerequisites for useful quantum computation. To date, quantum advantage has been demonstrated, for example, through violations of Bell inequalities and sampling-based quantum supremacy experiments. However, both forms of advantage come with important caveats: Bell tests are not computationally difficult tasks, and the classical hardness of sampling experiments relies on unproven complexity-theoretic assumptions. Here we demonstrate an unconditional quantum advantage in information resources required for a computational task, realized on Quantinuum’s H1-1 trapped-ion quantum computer operating at a median two-qubit partial-entangler fidelity of 99.941(7)%. We construct a task for which the most space-efficient classical algorithm provably requires between 62 and 382 bits of memory, and solve it using only 12 qubits. Our result provides the most direct evidence yet that currently existing quantum processors can generate and manipulate entangled states of sufficient complexity to access the exponentiality of Hilbert space. This form of quantum advantage — which we call quantum information supremacy — represents a new benchmark in quantum computing, one that does not rely on unproven conjectures.

I’m very happy to field questions about this paper in the comments section.

Unrelated Announcement: As some of you might have seen, yesterday’s Wall Street Journal carried a piece by Dan Kagan-Kans on “The Rise of ‘Conspiracy Physics.'” I talked to the author for the piece, and he quoted this blog in the following passage:

This resentment of scientific authority figures is the major attraction of what might be called “conspiracy physics.” Most fringe theories are too arcane for listeners to understand, but anyone can grasp the idea that academic physics is just one more corrupt and self-serving establishment. The German physicist Sabine Hossenfelder has attracted 1.72 million YouTube subscribers in part by attacking her colleagues: “Your problem is that you’re lying to the people who pay you,” she declared. “Your problem is that you’re cowards without a shred of scientific integrity.”

In this corner of the internet, the scientist Scott Aaronson has written, “Anyone perceived as the ‘mainstream establishment’ faces a near-insurmountable burden of proof, while anyone perceived as ‘renegade’ wins by default if they identify any hole whatsoever in mainstream understanding.”

In response to my recent blog posts, which expressed views that are entirely boring and middle-of-the-road for Americans as a whole, American Jews, and Israelis (“yes, war to destroy Hamas is basically morally justified, even if there are innocent casualties, as the only possible way to a future of coexistence and peace”)—many people declared that I was a raving genocidal maniac who wants to see all Palestinian children murdered out of sheer hatred, and who had destroyed his career and should never show his face in public again.

Others, however, called me something even worse than a genocidal maniac. They called me a Republican!

So I’d like to state for the record:

(1) In my opinion, Trump II remains by far the worst president in American history—beating out the second-worst, either Trump I or Andrew Jackson. Trump is destroying vaccines and science and universities and renewable energy and sane AI policy and international trade and cheap, lifesaving foreign aid and the rule of law and everything else that’s good, and he’s destroying them because they’re good—because even if destroying them hurts his own voters and America’s standing in the world, it might hurt the educated elites even more. It’s almost superfluous to mention that, while Trump himself is neither of these things, the MAGA movement that will anoint his successor now teems with antisemites and Holocaust “revisionists.”

(2) Thus, I’ll continue to vote straight-ticket Democrat, and donate money to Democrats, so long as the Democrats in question are seriously competing for Zionist Jewish votes at all—as, for example, has every Democratic presidential candidate in my lifetime so far.

(3) If it came down to an Israel-hating Squad Democrat versus a MAGA Republican, I’m not sure what I’d do, but I’d plausibly sit out the election or lodge a protest vote.

(4) In the extremely unlikely event that I had to choose between an Israel-hating Squad Democrat and some principled anti-MAGA Republican like Romney or Liz Cheney—then and only then do I expect that I’d vote Republican, for the first time in my life, a new and unfamiliar experience.

In my last post, I wrote about all the hate mail I’ve received these past few days. I even shared a Der-Stürmer-like image of a bloodthirsty, hook-nosed Orthodox Jew that some troll emailed me, after he’d repeatedly promised to send me a “diagram” that would improve my understanding of the Middle East. (Incredibly, commenters on Peter Woit’s blog then blamed me for this antisemitic image, mistakenly imagining that I’d created it myself, and then used their false assumption as further proof of my mental illness.)

Thanks to everyone who wrote to ask whether I’m holding up OK. The answer is: better than you’d expect! The first time you get attacked by dozens of Internet randos, it does feel like your life is over. But the sixth or seventh time? After you’ve experienced, firsthand, how illusory these people’s power over you actually is—how they can’t even dent your scientific career, can’t separate you from any of the friends who matter most to you (let alone your family), can’t really do anything to you beyond whatever they induce you to do to yourself? Then the deadly wolves appear more like poodles yapping from behind a fence. Try it and see!

Today I want to focus on a different kind of message that’s been filling my inbox. Namely, people telling me to stay strong, to keep up my courage, that everything I wrote strikes them as just commonsense morality.

It won’t surprise anyone that many of these people are Jews. But almost as many are not. I was touched to hear from several of my non-Jewish scientific colleagues—ones I’d had no idea were in my corner—that they are in my corner.

Then there was the American Gentile who emailed me a story about how, seeing an Orthodox family after October 7, he felt an urge to run up and tell them that, if worst ever came to worst, they could hide in his basement (“and I own guns,” he added). Amusingly, he added that his wife successfully dissuaded him from actually making such an offer, pointing out that it might freak out the recipients.

I replied that, here in America, I don’t expect that I’ll ever need to hide in anyone’s basement. But, I added, the only reason I don’t expect it is that there are so many Americans who, regardless of any religious or ideological differences, would hide their Jewish neighbors in their basements if necessary.

I also—despite neither I nor this guy exactly believing in God—decided to write a blessing for him, which came out as follows:

May your seed multiply a thousandfold, for like King Cyrus of Persia, you are a righteous man among the Gentiles.  But also, if you’re ever in Austin, be sure to hit me up for tacos and beer.

I’m even grateful, in a way, to SneerClub, and to Woit and his minions. I’m grateful to them for so dramatically confirming that I’m not delusional: some portion of the world really is out to get me. I probably overestimated their power, but not their malevolence.

I’ve learned, for example, that there are no words, however balanced or qualified, with which I can express the concept that Israel needs to defeat Hamas for the sake of both Israeli and Palestinian children, which won’t lead to Woit calling me a “genocide apologist who wants to see all the children in Gaza killed.” Nor are there any words with which to express my solidarity with the Jewish Columbia students who, according to an official university investigation, were last year systematically excluded from campus social life, intimidated, and even assaulted, and which won’t earn me names from Woit like “a fanatic allied with America’s fascist dictator.” Even my months-long silence about these topics got me labeled as “complicit with fascism and genocide.”

Realizing this is oddly liberating. When your back is to the wall in that way, either you can surrender, or else you can defend yourself. Your enemy has already done you the “favor” of eliminating any third options. Which, again, is just Zionism in a nutshell. It’s the lesson not only of 3,000 years of Jewish history, but also of superhero comics and of much of the world’s literature and cinema. It takes a huge amount of ideological indoctrination before such things stop being obvious.

Reading the SneerClubbers’ armchair diagnoses of my severe mental illness, paranoia, persecution complex, grandiosity, etc. etc. I had the following thought, paraphrasing Shaw:

Yes, they’re absolutely right that psychologically well-adjusted people generally do figure out how to adapt themselves to the reigning morality of their social environment—as indicated by the Asch conformity test, the Milgram electric-shock experiment, and the other classics of social psychology.

It takes someone psychologically troubled, in one way or another, to persist in trying to adapt the reigning morality of their social environment to themselves.

If so, however, this suggests that all the moral progress of humanity depends on psychologically troubled people—a realization for which I’m deeply grateful.

Above is a typical sample of what’s been filling my inbox, all day every day. The emailers first ask me for reasoned dialogue—then, if I respond, they hit me with this stuff. I’m sharing because I think it’s a usefully accurate depiction of what several billion people, most academics in humanities fields, most who call themselves “on the right side of history,” and essentially all those attacking me genuinely believe about the world right now. Because of their anti-Nazism.

Hardly for the first time in my life, this weekend I got floridly denounced every five minutes—on SneerClub, on the blog of Peter Woit, and in my own inbox. The charge this time was that I’m a genocidal Zionist who wants to kill all Palestinian children purely because of his mental illness and raging persecution complex.

Yes, that’s right, I’m the genocidal one—me, whose lifelong dream is that, just like Germany and Japan rose from their necessary devastation in WWII to become pillars of our global civilization, so too the children in Gaza, the West Bank, Syria, Lebanon, and Iran will one day grow up in free and prosperous societies at peace with the West and with Israel. Meanwhile, those who demand an actual genocide of the Jews, another one—those who pray to Allah for it, who attempt it over and over, who preach it to schoolchildren, who celebrate their progress toward it in the streets—they’re all as innocent as lambs.

Yesterday, in The Free Press, came the report of a British writer who traveled to southern Lebanon, and met an otherwise ordinary young man there … who turned out to be excited for Muslims and Christians to join forces to slaughter all the Yahood, and who fully expected that writer would share his admiration for Hitler, the greatest Yahood-killer ever.

This is what the global far left has now allied itself with. This is what I’m right now being condemned for standing against, with commenter after commenter urging me to seek therapy.

To me, this raises a broader question: how exactly do you keep your sanity, when you live on a planet filled with brain-eaten zombies?

I’m still struggling with that question, but the best I’ve come up with is what I think of as the Weinberg Principle, after my much-missed friend and colleague here at UT Austin. Namely, I believe that it’s better to have one Steven Weinberg on your side while the rest of humanity is against you, than the opposite. Many other individuals (including much less famous ones) would also work here in place of Steve, but I’ll go with him because I think most of my readers would agree to three statements:

Steve’s mind was more in sync with the way the universe really works, than nearly anyone else’s in history. He was to being free from illusions what Usain Bolt is to running or Magnus Carlsen is to chess.Steve’s toenail clippings constituted a greater contribution to particle physics than would the life’s work of a hundred billion Peter Woits.Steve’s commitment to Israel’s armed self-defense, and to Zionism more generally, made mine look weak and vacillating in comparison. No one need wonder what he would’ve said about Israel’s current war of survival against the Iranian-led terror axis.

Maybe it’s possible to wake the zombies up. Yoram Arnon, for example, wrote the following eloquent answer on Quora, in response to the question “Why are so many against freeing Palestine?”:

When Westerners think about freedom they think about freedom of speech, freedom of expression, freedom of movement, freedom of religion, freedom to form political parties, etc.

When Palestinians say “Free Palestine” they mean freedom from Jews, and from Israel’s existence. They’re advocating for the abolition of Israel, replacing it with an Arab country.

Israel is the only country in the Middle East that is free, in the Western sense of the word. If Israel were to disappear, Palestinians would fall under an autocratic regime, just like every other Arab country, with none of the above freedoms. And, of course, Israelis would suffer a terrible fate at their hands.

Pro Palestinians are either unable to see this, or want exactly that, but thankfully many in the West do see this – the same “many” that are against “freeing Palestine”.

Palestinians need to accept Israel’s right to exist, and choose to coexist peacefully alongside it, for them to have the peace and freedom the West wants for them.

Maybe reading words like these—or the words of Coleman Hughes, or Douglas Murray, or Hussein Aboubakr Mansour, or Yassine Meskhout, or John Aziz, or Haviv Rettig Gur, or Sam Harris, or the quantum computing pioneer David Deutsch—can boot a few of the zombies’ brains back up. But even then, I fear that these reboots will be isolated successes. For every one who comes back online, a thousand will still shamble along in lockstep, chanting “brainsssssss! genocide! intifada!”

I’m acutely aware of how sheer numbers can create the illusion of argumentative strength. I know many people who were sympathetic to Israel immediately after October 7, but then gradually read the room, saw which side their bread was buttered on, etc. etc. and became increasingly hostile. My reaction, of course, has been exactly the opposite. The bigger the zombie army I see marching against me, the less inclined I feel to become a zombie myself—and the clearer to me becomes the original case for the Zionist project.

So to the pro-Zionist students—Jewish of course, but also Christian, Muslim, Hindu, atheist, and everyone else—who feel isolated and scared to speak right up now, and who also often email me, here’s what I say. Yes, the zombies vastly outnumber us, but on the other hand, they’re zombies. Some of the zombies know longer words than others, but so far, not one has turned out to have a worldview terribly different from that of the image at the top of this post.

I’ll keep the comments closed, for much the same reasons I did in my last post.  Namely, while there are many people of all opinions and backgrounds with whom one can productively discuss these things, there are many more with whom one can’t. Furthermore, experience has shown that the latter can disguise themselves as the former for days on end, and thereby execute a denial-of-service attack on any worthwhile and open public discussion.

Suppose a man has already murdered most of your family, including several of your children, for no other reason than that he believes your kind doesn’t deserve to exist on earth. The murderer was never seriously punished for this, because most of your hometown actually shared his feelings about your family. They watched the murders with attitudes ranging from ineffectual squeamishness to indifference to unconcealed glee.

Now the man has kidnapped your last surviving child, a 9-year-old girl, and has tied her screaming to train tracks. You can pull a lever to divert the train and save your daughter. But there’s a catch, as there always is in these moral dilemmas: namely, the murderer has also tied his own five innocent children to the tracks, in such a way that, if you divert the train, then it will kill his children. What’s more, the murderer has invited the entire town to watch you, pointing and screaming “SHAME!!” as you agonize over your decision. He’s persuaded the town that, if you pull the lever, then having killed five of his children to save only one of yours, you’re a far worse murderer than he ever was. You’re so evil, in fact, that he’s effectively cleansed of all guilt for having murdered most of your family first, and the town is cleansed of all guilt for having cheered that. Nothing you say can possibly convince the town otherwise.

The question is, what do you do?

Zionism, to define it in one sentence, is the proposition that, in the situation described, you have not merely a right but a moral obligation to pull the lever—and that you can do so with your middle finger raised high to the hateful mob. Zionism is the belief that, while you had nothing against the murderer’s children, while you would’ve wanted them to grow up in peace and happiness, and while their anguished screams will weigh on your conscience forever, as your children’s screams never weighed on the murderer’s conscience, or on the crowd’s—even so, the responsibility for those children’s deaths rests with their father for engineering this whole diabolical situation, not with you. Zionism is the idea that the correct question here is the broader one: “which choice will bring more righteousness into the world, which choice will better embody the principle that no one’s children are to be murdered going forward?” rather than the narrowly utilitarian question, “which choice will lead to fewer children getting killed right this minute?” Zionism is the conviction that, if most of the world fervently believes otherwise, than most of the world is mistaken—as the world has been mistaken again and again about the biggest ethical questions all through the millennia.

Zionism, so defined, is the deepest moral belief that I have. It’s deeper than any of my beliefs about “politics” in the ordinary sense. Ironically, it’s even deeper than my day-to-day beliefs about the actual State of Israel and its neighbors. I might, for example, despise Benjamin Netanyahu and his ministers, might consider them incompetent and venal, might sympathize with the protesters who’ve filled the streets of Tel Aviv to demand their removal. Even so, when the murderer ties my child to the train tracks and the world cheers the murderer on, not only will I pull the lever myself, I’ll want Benjamin Netanyahu to pull the lever if he gets to it first.

Crucially, everything worthwhile in my life came when, and only when, I chose to be “Zionist” in this abstract sense: that is, steadfast in my convictions even in the face of a jeering mob. As an example, I was able to enter college three years early, which set the stage for all the math and science I later did, only because I finally said “enough” to an incompetent school system where I was bullied and prevented from learning, and to teachers and administrators whose sympathies lay with the bullies. I’ve had my successes in quantum computing theory only because I persisted in what at the time was a fairly bizarre obsession, rather than working on topics that almost everyone around me considered safer, more remunerative, and more sensible.

And as the world learned a decade ago, I was able to date, get married, and have a family, only because I finally rejected what I took to be the socially obligatory attitude for male STEM nerds like me—namely, that my heterosexuality was inherently gross, creepy, and problematic, and that I had a moral obligation never to express romantic interest to women. Yes, I overestimated the number of people who ever believed that, but the fact that it was clearly a nonzero number had been deterrent enough for me. Crucially, I never achieved what I saw for years as my only hope in life, to seek out those who believed my heterosexuality was evil and argue them out of their belief. Instead I simply … well, I raised a middle finger to the Andrea Dworkins and Arthur Chus and Amanda Marcottes of the world. I went Deep Zionist on them. I asked women out, and some of those women (not having gotten the memo that I was “problematic,” gross, and worthless) said yes, and one of them became my wife and the mother of my children.

Today, because of the post-October-7 public stands I’ve taken in favor of Israel’s continued existence, I deal with emails and social media posts day after day calling me a genocidal baby-killing monster. I’ve lost perhaps a dozen friends (while retaining hundreds more friends, and gaining some new ones). The haters’ thought appears to be that, if they can just raise the social cost high enough, I’ll finally renounce my Zionist commitments and they can notch another win. In this, they oddly mirror Hamas, Hezbollah, and the IRGC, who think that, if they can just kill and maim enough Israelis, the hated “settler-colonialist rats” will all scurry back to Poland or wherever else they came from (best not to think too hard about where they did come from, what was done to them in those places, how the Palestinian Arabs of the time felt about what was done to them, or how the survivors ended up making a last stand in their ancestral home of Israel—even afterward, repeatedly holding out olive branches that were met time after time with grenades).

Infamously, Israel’s enemies have failed to understand for a century that, the more they rape and murder, the more Zionist the hated Zionists will become, because unlike the French in Algeria or whatever, most of the Zionists have no other land to go back to: this is it for them. In the same way, my own haters don’t understand that, the more they despise me for being myself, the more myself I’ll be, because I have no other self to turn into.

I’m not opening the comments on this post, because there’s nothing here to debate. I’m simply telling the world my moral axioms. If I wrote these words, then turned to pleading with commenters who hated me because of them, then I wouldn’t really have meant the words, would I?

To my hundreds of dear friends and colleagues who’ve stood by me the past two years, to the Zionists and even just sympathetic neutrals who’ve sent me countless messages of support, but who are too afraid (and usually, too junior in their careers) to speak up in public themselves: know that I’ll use the protections afforded by my privileged position in life to continue speaking on your behalf. Know that I’m infinitely grateful, that you give me strength, and that if I can give you a nanoparticle of strength back to you, then my entire life wasn’t in vain. And if I go silent on this stuff from time to time, for the sake of my mental health, or to spend time on quantum computing research or my kids or the other things that bring me joy—never take that to mean that I’ve capitulated to the haters.

To the obsessive libelers, the Peter Woits and other snarling nobodies, the self-hating Jews, and those who’d cheer to see Israel “decolonized” and my friends and family there murdered, I say—well, I don’t say anything; that’s the point! This is no longer a debate; it’s a war, and I’ll simply stand my ground as long as I’m able. Someday I might forgive the Gentiles among you if you ever see the light, if you ever realize how your unreflective, social-media-driven “anti-fascism” led you to endorse a program that leads to the same end as the original Nazi one. The Jews among you I’ll never forgive, because you did know better, and still chose your own comfort over the physical survival of your people.

It might as well be my own hand on the madman’s lever—and yet, while I grieve for all innocents, my soul is at peace, insofar as it’s ever been at peace about anything.

Update (Aug. 29): This post was born of two years of frustration. It was born of trying, fifty or a hundred times since October 7, to find common ground with the anti-Zionists who emailed me, messaged me, etc.—“hey, obviously neither of us wants any children killed or starved, we both have many bones to pick with the current Israeli government, but surely we at least agree on the necessity of defeating Hamas, right? right??“—only to discover, again and again, that the anti-Zionists had no interest in any of this. With the runaway success of the global PR campaign against Israel—i.e., of Sinwar’s strategy—and with the rise of figures like Mamdani (and his right-wing counterparts) all over the Western world, anti-Zionists smell blood in the water nowadays. And so, no matter how reasonable they presented themselves at first, eventually they’d come out with “why can’t the Jews just go back to Germany and Poland?” or “the Holocaust was just one more genocide among many; it doesn’t deserve any special response,” or “why can’t we dismantle Israel and have a secular state, with a Jewish minority and a majority that’s sworn to kill all Jews as soon as possible?” And then I realize, with a gasp, that we Jews really are mostly on our own in a cruel and terrifying world—just like we’ve been throughout history.

To say that this experience radicalized me would be an understatement. Indeed, my experience has been that even most Israelis, who generally have far fewer illusions than we diaspora Jews, don’t understand the vastness of the chasm that now exists. They imagine that they can have a debate similar to the debates playing out within Israel—one that presupposes basic factual knowledge and the parameters of the problem (e.g., that clearly we can’t put 7 million Jews under the mercy of Hamas). The rationale for Zionism feels so obvious to them as to be cringe. Except that, to the rest of the world, it isn’t.

We’re not completely on our own though. There remain decent people of every background, who understand the stakes and feel the weight of history—and I regularly hear from them. And whatever your criticisms of Israel’s current tactics, so long as you accept the almost comically overwhelming historical case for the necessity of Jewish self-defense, this post wasn’t aimed at you, and you and I probably could discuss these matters. It’s just that the anti-Zionists scream so loudly, suck up so much oxygen, that we definitely can’t discuss in public. Maybe in person sometime, face to face.