~scottaaronson_blog | Bookmarks (22)

Progress in quantum complexity theory! In 2000, John Watrous showed that the Group Non-Membership problem is in the complexity class QMA (Quantum Merlin-Arthur). In other words, if some element g is not contained in a given subgroup H of an exponentially large finite group G, which is specified via a black box, then...

Last week I visited Harvard and MIT, and as advertised in my last post, gave the Yip Lecture at Harvard on the subject “How Much Math Is Knowable?” The visit was hosted by Harvard’s wonderful Center of Mathematical Sciences and Applications (CMSA), directed by my former UT Austin colleague Dan Freed. Thanks so much to […]

Every week, I tell myself I won’t do yet another post about the asteroid striking American academia, and then every week events force my hand otherwise. No one on earth—certainly no one who reads this blog—could call me blasé about the issue of antisemitism at US universities. I’ve blasted the takeover of entire departments and […]

A friend and I were discussing whether there’s anything I could possibly say, on this blog, in 2025, that wouldn’t provoke an outraged reaction from my commenters. So I started jotting down ideas. Let’s see how I did.

In this terrifying time for the world, I’m delighted to announce a little glimmer of good news. I’m receiving a large grant from the wonderful Open Philanthropy, to build up a group of students and postdocs over the next few years, here at UT Austin, to do research in theoretical computer science that’s motivated by […]

The United States is now a country that disappears people. Visa holders, green card holders, and even occasionally citizens mistaken for non-citizens: Trump’s goons can now seize them off the sidewalk at any time, handcuff them, detain them indefinitely in a cell in Louisiana with minimal access to lawyers, or even fly them to an […]

Leftist Students and Faculty: We’d sooner burn universities to the ground than allow them to remain safe for the hated Zionist Jews, the baby-killing demons of the earth. We’ wi’ll disrupt their classes, bar them from student activities, smash their Hillel centers, take over campus buildings and quads, and chant for Hezbollah and the Al-Aqsa […]

These days, any quantum computing post I write ought to begin with the disclaimer that the armies of Sauron are triumphing around the globe, this is the darkest time for humanity most of us have ever known, and nothing else matters by comparison. Certainly not quantum computing. Nevertheless stuff happens in quantum computing and it […]

The world is complicated, and the following things can all be true: (1) Trump and his minions would love to destroy American academia, to show their power, thrill their base, and exact revenge on people who they hate. They will gladly seize on any pretext to do so. For those of us, whatever our backgrounds, […]

Please enjoy Harvard’s Jacob Barandes and yours truly duking it out for 2.5 hours on YouTube about the interpretation of quantum mechanics, and specifically Jacob’s recent proposal involving “indivisible stochastic dynamics,” with Curt Jaimungal as moderator. As always, I strongly recommend watching with captions turned on and at 2X speed. To summarize what I learned […]

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 […]

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 Tur...

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 […]

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

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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

Err, happy MLK Day! This week represents the convergence of so many plotlines that, if it were the season finale of some streaming show, I’d feel like the writers had too many balls in the air. For the benefit of the tiny part of the world that cares what I think, I offer the following […]

Apparently Jensen Huang, the CEO of NVIDIA, opined on an analyst call this week that quantum computing was plausibly still twenty years away from being practical. As a direct result, a bunch of publicly-traded quantum computing companies (including IonQ, Rigetti, and D-Wave) fell 40% or more in value, and even Google/Alphabet stock fell on the […]