Scott Aaronson's Blog, page 4

The Evil Vector

Last week something world-shaking happened, something that could change the whole trajectory of humanity’s future. No, not that—we’ll get to that later.

For now I’m talking about the “Emergent Misalignment” paper. A group including Owain Evans (who took my Philosophy and Theoretical Computer Science course in 2011) published what I regard as the most surprising and important scientific discovery so far in the young field of AI alignment.  (See also Zvi’s commentary.) Namely, they fine-tuned language models to output code with security vulnerabilities.  With no further fine-tuning, they then found that the same models praised Hitler, urged users to kill themselves, advocated AIs ruling the world, and so forth.  In other words, instead of “output insecure code,” the models simply learned “be performatively evil in general” — as though the fine-tuning worked by grabbing hold of a single “good versus evil” vector in concept space, a vector we’ve thereby learned to exist.

(“Of course AI models would do that,” people will inevitably say. Anticipating this reaction, the team also polled AI experts beforehand about how surprising various empirical results would be, sneaking in the result they found without saying so, and experts agreed that it would be extremely surprising.)

Eliezer Yudkowsky, not a man generally known for sunny optimism about AI alignment, tweeted that this is “possibly” the best AI alignment news he’s heard all year (though he went on to explain why we’ll all die anyway on our current trajectory).

Why is this such a big deal, and why did even Eliezer treat it as good news?

Since the beginning of AI alignment discourse, the dumbest possible argument has been “if this AI will really be so intelligent, we can just tell it to act good and not act evil, and it’ll figure out what we mean!”  Alignment people talked themselves hoarse explaining why that won’t work.

Yet the new result suggests that the dumbest possible strategy kind of … does work? In the current epoch, at any rate, if not in the future?  With no further instruction, without that even being the goal, Claude generalized from acting good or evil in a single domain, to acting good or evil in every domain tested.  Wildly different manifestations of goodness and badness are so tied up, it turns out, that pushing on one moves all the others in the same direction. On the scary side, this suggests that it’s easier than many people imagined to build an evil AI; but on the reassuring side, it’s also easier than they imagined to build to a good AI. Either way, you just drag the internal Good vs. Evil slider to wherever you want it!

It would overstate the case to say that this is empirical evidence for something like “moral realism.” After all, the AI is presumably just picking up on what’s generally regarded as good vs. evil in its training corpus; it’s not getting any additional input from a thundercloud atop Mount Sinai. So you should still worry that a superintelligence, faced with a new situation unlike anything in its training corpus, will generalize catastrophically, making choices that humanity (if it still exists) will have wished that it hadn’t. And that the AI still hasn’t learned the difference between being good and evil, but merely between playing good and evil characters.

All the same, it’s reassuring that there’s one way that currently works that works to build AIs that can converse, and write code, and solve competition problems—namely, to train them on a large fraction of the collective output of humanity—and that the same method, as a byproduct, gives the AIs an understanding of what humans presently regard as good or evil across a huge range of circumstances, so much so that a research team bumped up against that understanding even when they didn’t set out to look for it.

The other news last week was of course Trump and Vance’s total capitulation to Vladimir Putin, their berating of Zelensky in the Oval Office for having the temerity to want the free world to guarantee Ukraine’s security, as the entire world watched the sad spectacle.

Here’s the thing. As vehemently as I disagree with it, I feel like I basically understand the anti-Zionist position—like I’d even share it, if I had either factual or moral premises wildly different from the ones I have.

Likewise for the anti-abortion position. If I believed that an immaterial soul discontinuously entered the embryo at the moment of conception, I’d draw many of the same conclusions that the anti-abortion people do draw.

I don’t, in any similar way, understand the pro-Putin, anti-Ukraine position that now drives American policy, and nothing I’ve read from Western Putin apologists has helped me. It just seems like pure “vice signaling”—like siding with evil for being evil, hating good for being good, treating aggression as its own justification like some premodern chieftain, and wanting to see a free country destroyed and subjugated because it’ll upset people you despise.

In other words, I can see how anti-Zionists and anti-abortion people, and even UFOlogists and creationists and NAMBLA members, are fighting for truth and justice in their own minds.  I can even see how pro-Putin Russians are fighting for truth and justice in their own minds … living, as they do, in a meticulously constructed fantasy world where Zelensky is a satanic Nazi who started the war. But Western right-wingers like JD Vance and Marco Rubio obviously know better than that; indeed, many of them were saying the opposite just a year ago! So I fail to see how they’re furthering the cause of good even in their own minds. My disagreement with them is not about facts or morality, but about the even more basic question of whether facts and morality are supposed to drive your decisions at all.

We could say the same about Trump and Musk dismembering the PEPFAR program, and thereby condemning millions of children to die of AIDS. Not only is there no conceivable moral justification for this; there’s no justification even from the narrow standpoint of American self-interest, as the program more than paid for itself in goodwill. Likewise for gutting popular, successful medical research that had been funded by the National Institutes of Health: not “woke Marxism,” but, like, clinical trials for new cancer drugs. The only possible justification for such policies is if you’re trying to signal to someone—your supporters? your enemies? yourself?—just how callous and evil you can be. As they say, “the cruelty is the point.”

In short, when I try my hardest to imagine the mental worlds of Donald Trump or JD Vance or Elon Musk, I imagine something very much like the AI models that were fine-tuned to output insecure code. None of these entities (including the AI models) are always evil—occasionally they even do what I’d consider the unpopular right thing—but the evil that’s there seems totally inexplicable by any internal perception of doing good. It’s as though, by pushing extremely hard on a single issue (birtherism? gender transition for minors?), someone inadvertently flipped the signs of these men’s good vs. evil vectors. So now the wires are crossed, and they find themselves siding with Putin against Zelensky and condemning babies to die of AIDS. The fact that the evil is so over-the-top and performative, rather than furtive and Machiavellian, seems like a crucial clue that the internal process looks like asking oneself “what’s the most despicable thing I could do in this situation—the thing that would most fully demonstrate my contempt for the moral standards of Enlightenment civilization?,” and then doing that thing.

Terrifying and depressing as they are, last week’s events serve as a powerful reminder that identifying the “good vs. evil” direction in concept space is only a first step. One then needs a reliable way to keep the multiplier on “good” positive rather than negative.

Ryan Williams strikes again

Because of a recent breakthrough by Cook and Mertz on Tree Evaluation, Ryan now shows that every problem solvable in t time on a multitape Turing machine is also solvable in close to √t space
As a consequence, he shows that there are problems solvable in O(n) space that require nearly quadratic time on multitape Turing machines
If this could be applied recursively to boost the polynomial degree, then P≠PSPACE
On Facebook, someone summarized this result as “there exists an elephant that can’t fit through a mouse hole.” I pointed out that for decades, we only knew how to show there was a blue whale that didn’t fit through the mouse hole
I’ll be off the Internet for much of today (hopefully only today?) because of jury duty! Good thing you’ll have Ryan’s amazing new paper to keep y’all busy…

FAQ on Microsoft’s topological qubit thing

Q1. Did you see Microsoft’s announcement?
A. Yes, thanks, you can stop emailing to ask! Microsoft’s Chetan Nayak was even kind enough to give me a personal briefing a few weeks ago. Yesterday I did a brief interview on this for the BBC’s World Business Report, and I also commented for MIT Technology Review.

Q2. What is a topological qubit?
A. It’s a special kind of qubit built using nonabelian anyons, which are excitations that can exist in a two-dimensional medium, behaving neither as fermions nor as bosons. The idea grew out of seminal work by Alexei Kitaev, Michael Freedman, and others starting in the late 1990s. Topological qubits have proved harder to create and control than ordinary qubits.

Q3. Then why do people care about topological qubits?
A. The dream is that they could eventually be more resilient to decoherence than regular qubits, since an error, in order to matter, needs to change the topology of how the nonabelian anyons are braided around each other. So you’d have some robustness built in to the physics of your system, rather than having to engineer it laboriously at the software level (via quantum fault-tolerance).

Q4. Did Microsoft create the first topological qubit?
A. Well, they say they did!

Q5. Didn’t Microsoft claim the experimental creation of Majorana zero modes—a building block of topological qubits—back in 2018, and didn’t they then need to retract that claim?
A. Yep. Certainly that history is making some experts cautious about the new claim. When I asked Chetan Nayak how confident I should be, his response was basically “look, we now have a topological qubit that’s behaving fully as a qubit; how much more do people want?”

Q6. Is this a big deal?
A. If the claim stands, I’d say it’s a scientific milestone for the field of topological quantum computing and physics beyond. The number of topological qubits manipulated in a single experiment has then finally increased from 0 to 1, and depending on how you define things, arguably a “new state of matter” has even been created, one that doesn’t appear in nature (but only in Nature).

Q7. Is this useful?
A. Not yet! If anyone claims that a single qubit, or even 30 qubits, are already useful for speeding up computation, you can ignore anything else that person says. (Certainly Microsoft makes no such claim.) On the question of what we believe quantum computers will or won’t eventually be useful for, see like half the archives of this blog over the past twenty years.

Q8. Does this announcement vindicate topological qubits as the way forward for quantum computing?
A. Think of it this way. If Microsoft’s claim stands, then topological qubits have finally reached some sort of parity with where more traditional qubits were 20-30 years ago. I.e., the non-topological approaches like superconducting, trapped-ion, and neutral-atom have an absolutely massive head start: there, Google, IBM, Quantinuum, QuEra, and other companies now routinely do experiments with dozens or even hundreds of entangled qubits, and thousands of two-qubit gates. Topological qubits can win if, and only if, they turn out to be so much more reliable that they leapfrog the earlier approaches—sort of like the transistor did to the vacuum tube and electromechanical relay. Whether that will happen is still an open question, to put it extremely mildly.

Q9. Are there other major experimental efforts to build topological qubits?
A. No, it’s pretty much just Microsoft. Purely as a scientist who likes to see things tried, I’m grateful that one player stuck with the topological approach even when it ended up being a long, painful slog.

Q10. Is Microsoft now on track to scale to a million topological qubits in the next few years?
A. In the world of corporate PR and pop-science headlines, sure, why not? As Bender from Futurama says, “I can guarantee anything you want!” In the world of reality, a “few years” certainly feels overly aggressive to me, but good luck to Microsoft and good luck to its competitors! I foresee exciting times ahead, provided we still have a functioning civilization in which to enjoy them.

Toward a non-constant cancellation function

It now seems the switch of Cancel Culture has only two settings:

everything is cancellable—including giving intellectual arguments against specific DEI policies, or teaching students about a Chinese filler word (“ne-ge”) that sounds a little like the N-word, or elsenothing is cancellable—not even tweeting “normalize Indian hate” and “I was racist before it was cool,” shortly before getting empowered to remake the US federal government.

How could we possibly draw any line between these two extremes? Wouldn’t that require … judgment? Common sense? Consideration of the facts of individual cases?

I, of course, survived attempted cancellation by a large online mob a decade ago, led by well-known figures such as Amanda Marcotte and Arthur Chu. Though it was terrifying at the time—it felt like my career and even my life were over—I daresay that, here in 2025, not many people would still condemn me for trying to have the heartfelt conversation I did about nerds, feminism, and dating, deep in the comments section of this blog. My side has now conclusively “won” that battle. The once-terrifying commissars of the People’s Republic of Woke, who delighted in trying to ruin me, are now bound and chained, as whooping soldiers of the MAGA Empire drag them by their hair to the torture dungeons.

And this is … not at all the outcome I wanted? It’s a possible outcome that I foresaw in 2014, and was desperately trying to help prevent, through fostering open dialogue between shy male nerds and feminists? I’m now, if anything, more terrified for my little tribe of pro-Enlightenment, science-loving nerds than I was under the woke regime? Speaking of switches with only two settings.

Anyway, with whatever moral authority this experience vests in me, I’d like to suggest that, in future cancellation controversies, the central questions ought to include the following:

What did the accused person actually say or do? Disregarding all confident online discourse about what that “type” of person normally does, or wants to do.Is there a wider context that often gets cut from social media posts, but that, as soon as you know it, makes the incident seem either better or worse?How long ago was the offense: more like thirty years or like last week?Was the person in a radically different condition than they are now—e.g., were they very young, or undergoing a mental health episode, or reacting to a fresh traumatic incident, or drunk or high?Were the relevant cultural norms different when the offense happened? Did countless others say or do the same thing, and if so, are they also at risk of cancellation?What’s reasonable to infer about what the person actually believes? What do they want to have happen to whichever group they offended? What would they do to the group given unlimited power? Have they explicitly stated answers to these questions, either before or after the incident? Have they taken real-world actions by which we could judge their answers as either sincere or insincere?If we don’t cancel this person, what are we being asked to tolerate? Just that they get to keep teaching and publishing views that many people find objectionable? Or that they get to impose their objectionable views on an entire academic department, university, company, organization, or government?If we agree that the person said something genuinely bad, did they apologize or express regret? Or, if what they said got confused with something bad, did they rush to clarify and disclaim the bad interpretation?Did they not only refuse to clarify or apologize, but do the opposite? That is, did they express glee about what they were able to get away with, or make light of the suffering or “tears” of their target group?

People can debate how to weigh these considerations, though I personally put enormous weight on 8 and 9, what you could call the “clarification vs. glee axis.” I have nearly unlimited charity for people willing to have a good-faith moral conversation with the world, and nearly unlimited contempt for people who mock the request for such a conversation.

The sad part is that, in practice, the criteria for cancellation have tended instead to be things like:

Is the target giving off signals of shame, distress, and embarrassment—thereby putting blood in the water and encouraging us to take bigger bites?Do we, the mob, have the power to cancel this person? Does the person’s reputation and livelihood depend on organizations that care what we think, that would respond to pressure from us?

The trouble with these questions is that, not only are their answers not positively correlated with which people deserve to be cancelled, they’re negatively correlated. This is precisely how you get the phenomenon of the left-wing circular firing squad, which destroys the poor schmucks capable of shame even while the shameless, the proud racists and pussy-grabbers, go completely unpunished. Surely we can do better than that.

“If you’re not a woke communist, you have nothing to fear,” they claimed

Part of me feels bad not to have written for weeks about quantum error-correction or BQP or QMA or even the new Austin-based startup that launched a “quantum computing dating app” (which, before anyone asks, is 100% as gimmicky and pointless as it sounds).

But the truth is that, even if you cared narrowly about quantum computing, there would be no bigger story right now than the fate of American science as a whole, which for the past couple weeks has had a knife to its throat.

Last week, after I blogged about the freeze in all American federal science funding (which has since been lifted by a judge’s order), a Trump-supporting commenter named Kyle had this to say:

No, these funding cuts are not permanent. He is only cutting funds until his staff can identify which money is going to the communists and the wokes. If you aren’t a woke or a communist, you have nothing to fear.

Read that one more time: “If you aren’t woke or a communist, you have nothing to fear.”

Can you predict what happened barely a week later? Science magazine now reports that the Trump/Musk/DOGE administration is planning to cut the National Science Foundation’s annual budget from $9 billion to only $3 billion (Biden, by contrast, had proposed an increase to $10 billion). Other brilliant ideas under discussion, according to the article, are to use AI to evaluate the grant proposals (!), and to shift the little NSF funding that remains from universities to private companies.

To be clear: in the United States, NSF is the only government agency whose central mission is curiosity-driven basic research—not that other agencies like DOE or NIH or NOAA, which also fund basic research, are safe from the chopping block either.

Maybe Congress, where support for basic science has long been bipartisan, will at some point grow some balls and push back on this. If not, though: does anyone seriously believe that you can cut the NSF’s budget by two-thirds while targeting only “woke communism”? That this won’t decimate the global preeminence of American universities in math, physics, computer science, astronomy, genetics, neuroscience, and more—preeminence that took a century to build?

Or does anyone think that I, for example, am a “woke communist”? I, the old-fashioned Enlightenment liberal who repeatedly risked his reputation to criticize “woke communism,” who the “woke communists” denounced when they noticed him at all, and who narrowly survived a major woke cancellation attempt a decade ago? Alas, I doubt any of that will save me: I presumably won’t be able to get NSF grants either under this new regime. Nor will my hundreds of brilliant academic colleagues, who’ve done what they can to make sure the center of quantum computing research remains in America rather than China or anywhere else.

I of course have no hope that the “Kyles” of the world will ever apologize to me for their prediction, their promise, being so dramatically wrong. But here’s my plea to Elon Musk, J. D. Vance, Joe Lonsdale, Curtis Yarvin, the DOGE boys, and all the readers of this blog who are connected to their circle: please prove me wrong, and prove Kyle right.

Please preserve and increase the NSF’s budget, after you’ve cleansed it of “woke communism” as you see fit. For all I care, add a line item to the budget for studying how to build rockets that are even bigger, louder, and more phallic.

But if you won’t save the NSF and the other basic research agencies—well hey, you’re the ones who now control the world’s nuclear-armed superpower, not me. But don’t you dare bullshit me about how you did all this so that merit-based science could once again flourish, like in the days of Newton and Gauss, finally free from meddling bureaucrats and woke diversity hires. You’d then just be another in history’s endless litany of conquering bullies, destroying what they can’t understand, no more interesting than all the previous bullies.

The duty of stating the obvious

1. Trump’s proposal for the US to “take over” Gaza and expel its inhabitants is, like nearly everything else Trump has said and done over the past two weeks and indeed the past decade, completely batshit insane.

2. As with countless other Trump proposals, I don’t see that it will actually happen — both because most Gazans will refuse to leave, and because Arab countries will refuse to take them.

3. I wonder whether all the anti-Israel activists in the US who withheld their vote (or even switched to Trump) to punish Biden and Harris for their support of Israel, are now happy with what they’ve gotten.

4. The solution has always been for some government to develop Gaza for the benefit of its inhabitants, rather than as a terror-base for attacking Israel. Hamas and UNRWA have shown that they’ll never do that. But the postwar administration of Germany and Japan demonstrates what’s possible in one generation if the will exists.

5. I wish the anti-Israel people would join me in demanding that. They ought to reflect that, if their only counteroffer is “Israel gets eradicated and its Jews return to the countries that murdered or expelled their families,” then they’re demanding something even more fantastical than Trump’s proposal.

Hymn to be recited for the next thousand mornings

A few years ago, scientists feared they’d lose their jobs if they said anything against diversity programs.

I was against that.

Now scientists fear they’ll lose their jobs if they say anything for diversity programs.

I’m against that too.

A few years ago, if you didn’t list your pronouns, you were on the wrong side of history.

I was on the wrong side of history.

Now, if you want equal rights for your trans friends, you’re an enemy of the people.

I’m an enemy of the people.

Then, they said the woke triumph over universities, the media, and Silicon Valley had bent the moral arc of the universe and overrode individual conscience.

I chose conscience anyway.

Now they say the MAGA triumph over the White House, Congress, the Supreme Court, and (again) Silicon Valley has bent the moral arc back.

I choose conscience again.

Then and now the ideologues say: don’t you realize you need to pick a side?

What they don’t understand is that I have picked a side.

The American science funding catastrophe

It’s been almost impossible to get reliable information this week, but here’s what my sources are telling me:

There is still a complete freeze on money being disbursed from the US National Science Foundation. Well, there’s total chaos in the federal government much more broadly, a lot of it more immediately consequential than the science freeze, but I’ll stick for now to my little corner of the universe.

The funding freeze has continued today, despite the fact that Trump supposedly rescinded it yesterday after a mass backlash. Basically, program directors remain in a state of confusion, paralysis, and fear. Where laws passed by Congress order them to do one thing, but the new Executive Orders seem to order the opposite, they’re simply doing nothing, waiting for clarification, and hoping to preserve their jobs.

Hopefully the funding will restart in a matter of days, after NSF and other agencies go through and cancel any expense that can be construed as DEI-related. Hopefully this will be like the short-lived Muslim travel ban of 2017: a “shock-and-awe” authoritarian diktat that thrills the base but quickly melts on contact with the reality of how our civilization works.

The alternative is painful to contemplate. If the current freeze drags on for months, tens of thousands of grad students and postdocs will no longer get stipends, and will be forced to quit. Basic science in the US will essentially grind to a halt—and even if it eventually restarts, an entire cohort of young physicists, mathematicians, and biologists will have been lost, while China and other countries race ahead in those fields.

Also, even if the funding does restart, the NSF and other federal agencies are now under an indefinite hiring freeze. If not quickly lifted, this will shrink these agencies and cripple their ability to carry out their missions.

If you voted for Trump, because you wanted to take a hammer to the woke deep state or whatever, then please understand: you may or may not have realized you were voting for this, exactly, but this is what you’ve gotten. In place of professionals who you dislike and who are sometimes systematically wrong, the American spaceship is now being piloted by drunken baboons, mashing the controls to see what happens. I hope you like the result.

Meanwhile, to anyone inside or outside the NSF who has more information about this rapidly-evolving crisis: I strongly encourage you to share whatever you know in the comments section. Or get in touch with me by email. I’ll of course respect all wishes for anonymity, and I won’t share anything without permission. But you now have a chance—some might even say an enviable chance—to put your loyalty to science and your country above your fear of a bully.

Update: By request, you can also contact me at ScottAaronson.49 on the encrypted messaging app Signal.

Good news for once! A faster Quantum Fourier Transform

Update: In the comments, Craig Gidney points out that Ronit’s O(n log2 n) quantum circuits for the exact QFT were already published by Cleve and Watrous in 2000 (in a paper whose main point was something else, parallelization). Ronit’s O(n (log log n)2) circuits for the approximate QFT still appear to be new (Gidney says he and others knew related techniques but had never explicitly combined them). Of course, while the exact result was Platonically “known,” it wasn’t sufficiently well known that any of the four quantum algorithms experts I’d consulted had heard of it! Hopefully this very post will go some way toward fixing the situation.

In my last post, I tried to nudge the arc of history back onto the narrow path of reasoned dialogue, walking the mile-high tightrope between shrill, unsupported accusation and naïve moral blindness. For my trouble, I was condemned about equally by leftists for my right-wing sympathies and by rightists for my left-wing ones. So today, I’ll ignore the fate of civilization and return to quantum computing theory: a subject that’s reliably brought joy to my life for a quarter-century, and still does, even as my abilities fade. It turns out there is a consolation for advancing age and senility, and it’s called “students.”

This fall, I returned from my two-year leave at OpenAI to teach my undergrad Introduction to Quantum Information Science course at UT Austin. This course doesn’t pretend to bring students all the way to the research frontier, and yet sometimes it’s done so anyway. It was in my first offering of Intro to QIS, eight years ago, that I encountered the then 17-year-old Ewin Tang, who broke the curve and then wanted an independent study project. So I gave her the problem of proving that the Kerenidis-Prakash quantum algorithm achieves an exponential speedup over any classical algorithm for the same task, not expecting anything to come of it. But after a year of work, Ewin refuted my conjecture by dequantizing the K-P algorithm—a breakthrough that led to the demolition of many other hopes for quantum machine learning. (Demolishing people’s hopes? In complexity theory, we call that a proud day’s work.)

Today I’m delighted to announce that my undergrad quantum course has led to another quantum advance. One day, after my lecture, a junior named Ronit Shah came to me with an idea for how best to distinguish three possible states of a qubit, rather than only two. For some reason I didn’t think much of it at the time, even though it would later turn out that Ronit had essentially rediscovered the concept of POVMs, the Pretty Good Measurement (PGM), and the 2002 theorem that the PGM is optimal for distinguishing sets of states subject to a transitive group action.

Later, after I’d lectured about Shor’s algorithm, and one of its centerpieces, the O(n2)-gate recursive circuit for the Quantum Fourier Transform, Ronit struck a second time. He told me it should be possible to give a smaller circuit by recursively reducing the n-qubit QFT to two (n/2)-qubit QFTs, rather than to a single (n-1)-qubit QFT.

This was surely just a trivial confusion, perfectly excusable in an undergrad. Did Ronit perhaps not realize that an n-qubit unitary is actually a 2n×2n matrix, so he was proposing to pass directly from 2n×2n to 2n/2×2n/2, rather than to 2n-1×2n-1?

No, he said, he understood that perfectly well. He still thought the plan would work. Then he emailed me a writeup—claiming to implement the exact n-qubit QFT in O(n log2n) gates, the first-ever improvement over O(n2), and also the approximate n-qubit QFT in O(n (log log n)2) gates, the first-ever improvement over O(n log n). He used fast integer multiplication algorithms to make the new recursions work.

At that point, I did something I’m still ashamed of: I sat on Ronit’s writeup for three weeks. When I at last dug it out of my inbox and read it, I could discover no reason why it was wrong, or unoriginal, or unimportant. But I didn’t trust myself, so with Ronit’s permission I sent the work to some of my oldest quantum friends: Ronald de Wolf, Cris Moore, Andrew Childs, and Wim van Dam. They agreed, after some back-and-forth, that the new circuits looked legit. A keystone of Shor’s algorithm, of quantum computing itself, and of my undergrad class had seen its first real improvement since 1994.

Last night Ronit’s paper appeared on the arXiv where you can read it.

In case anyone asks: no, this probably has no practical implication for speeding up factoring on a quantum computer, since the QFT wasn’t the expensive part of Shor’s algorithm anyway—that’s the modular exponentiation—and also, the O(n log n) approximate QFT would already have been used in practice. But it’s conceivable that Ronit’s circuits could speed up other practical quantum computing tasks! And no, we have no idea what’s the ultimate limit here, as usual in circuit complexity. Could the exact n-qubit QFT even be doable in O(n) gates?

I’d love for Ronit to continue in quantum computing theory. But in what’s surely a sign of the times, he’s just gone on leave from UT to intern at an AI hardware startup. I hope he returns and does some more theory, but if he doesn’t, I’m grateful that he shared this little gem with us on his way to more world-changing endeavors.

Open letter to any Shtetl-Optimized readers who know Elon

Did Elon Musk make a Nazi salute? Well, not exactly. As far as I can tell, the truth is that he recklessly and repeatedly made a hand gesture that the world’s millions of Nazi sympathizers eagerly misinterpreted as a Nazi salute. He then (the worse part) declined to clarify or apologize in any way, opting instead for laugh emojis.

I hasten to add: just like with Trump’s Charlottesville dogwhistles, I find it ludicrous to imagine that Elon has any secret desire to reopen the gas chambers or whatever—and not only because of Elon’s many pro-Zionist and philosemitic actions, statements, and connections. That isn’t the issue, so don’t pretend I think it is.

Crucially, though, “not being a literal Nazi” isn’t fully exculpatory. I don’t want the overlords of the planet treating these matters as jokes. I want them to feel the crushing weight of history, exactly like I would feel it in their shoes.

Regardless of my distaste for everything that happened to reach this point, Elon is now in a unique position to nudge Trump in the direction of liberality and enlightenment on various issues.  And while I doubt Elon finds time to read Shtetl-Optimized between his CEOing, DOGEing, tweeting, and video game speedruns, I know for certain that there are multiple readers of this blog to whom Elon has listened in the past—and those people are now in a unique position too!

A public “clarification” from Elon—not an apology, not an admission of guilt, but just an acknowledgment that he knows why sleeping dragons like Nazism shouldn’t be poked for shits and giggles, that he’ll try to be careful in the future—would be a non-negligible positive update for me about the future of the world.

I understand exactly why he doesn’t want to do it: because he doesn’t want to grant any legitimacy to what he sees as the biased narrative of a legacy media that despises him. But granting some legitimacy to that narrative is precisely what I, a classically liberal Jewish scientist who bears the battle scars of attempted woke cancellation, am asking him to do. I’m asking him to acknowledge that he’s now by any measure one of the most powerful people on the planet, that with great power comes great responsibility, and that fascism is a well-known failure mode for powerful rightists, just like Communism is a well-known failure mode for leftists. I’m asking for reassurance that he takes that failure mode seriously, just like he correctly takes human extinction and catastrophic AI risk seriously.

Anyway, I figured it was worth a try, given how much I really believe might hinge on how Elon chooses to handle this. I don’t want to be kicking myself, for the rest of my life, that I had a chance to intervene in the critical moment and didn’t.