Updates (Dec. 5): The US Supreme Court has upheld Trump’s latest travel ban. I’m grateful to all the lawyers who have thrown themselves in front of the train of fascism, desperately trying to slow it down—but I could never, ever have been a lawyer myself. Law is fundamentally a make-believe discipline. Sure, there are times when it involves reason and justice, possibly even resembles mathematics—but then there are times when the only legally correct thing to say is, “I guess that, contrary to what I thought, the Establishment Clause of the First Amendment does let you run for president promising to discriminate against a particular religious group, and then find a pretext under which to do it. The people with the power to decide that question have decided it.” I imagine that I’d last about half a day before tearing up my law-school diploma in disgust, which is surely a personality flaw on my part.
In happier news, many of you may have seen that papers by the groups of Chris Monroe and of Misha Lukin, reporting ~50-qubit experiments with trapped ions and optical lattices respectively, have been published back-to-back in Nature. (See here and here for popular summaries.) As far as I can tell, these papers represent an important step along the road to a clear quantum supremacy demonstration. Ideally, one wants a device to solve a well-defined computational problem (possibly a sampling problem), and also highly-optimized classical algorithms for solving the same problem and for simulating the device, which both let one benchmark the device’s performance and verify that the device is solving the problem correctly. But in a curious convergence, the Monroe group and Lukin group work suggests that this can probably be achieved with trapped ions and/or optical lattices at around the same time that Google and IBM are closing in on the goal with superconducting circuits.
As everyone knows, the flaming garbage fire of a tax bill has passed the Senate, thanks to the spinelessness of John McCain, Lisa Murkowski, Susan Collins, and Jeff Flake. The fate of American higher education will now be decided behind closed doors, in the technical process of “reconciling” the House bill (which includes the crippling new tax on PhD students) with the Senate bill (which doesn’t—that one merely guts a hundred other things). It’s hard to imagine that this particular line item will occassion more than about 30 seconds of discussion. But, I dunno, maybe calling your Senator or Representative could help. Me, I left a voicemail message with the office of Texas Senator Ted Cruz, one that I’m confident Cruz and his staff will carefully consider.
Here’s talk show host Seth Meyers (scroll to 5:00-5:20):
“By 2027, half of all US households would pay more in taxes [under the new bill]. Oh my god. Cutting taxes was the one thing Republicans were supposed to be good at. What’s even the point of voting for a Republican if they’re going to raise your taxes? That’s like tuning in to The Kardashians only to see Courtney giving a TED talk on quantum computing.”
Speaking of which, you can listen to an interview with me about quantum computing, on a podcast called Data Skeptic. We discuss the basics and then the potential for quantum machine learning algorithms.
I got profoundly annoyed by an article called The Impossibility of Intelligence Explosion by François Chollet. Citing the “No Free Lunch Theorem”—i.e., the (trivial) statement that you can’t outperform brute-force search on random instances of an optimization problem—to claim anything useful about the limits of AI, is not a promising sign. In this case, Chollet then goes on to argue that most intelligence doesn’t reside in individuals but rather in culture; that there are hard limits to intelligence and to its usefulness; that we know of those limits because people with stratospheric intelligence don’t achieve correspondingly extraordinary results in life [von Neumann? Newton? Einstein? –ed.]; and finally, that recursively self-improving intelligence is impossible because we, humans, don’t recursively improve ourselves. Scattered throughout the essay are some valuable critiques, but nothing comes anywhere close to establishing the impossibility advertised in the title. Like, there’s a standard in CS for what it takes to show something’s impossible, and Chollet doesn’t even reach the same galaxy as that standard. The certainty that he exudes strikes me as wholly unwarranted, just as much as (say) the near-certainty of a Ray Kurzweil on the other side.
I suppose this is as good a place as any to say that my views on AI risk have evolved. A decade ago, it was far from obvious that known methods like deep learning and reinforcement learning, merely run with much faster computers and on much bigger datasets, would work as spectacularly well as they’ve turned out to work, on such a wide variety of problems, including beating all humans at Go without needing to be trained on any human game. But now that we know these things, I think intellectual honesty requires updating on them. And indeed, when I talk to the AI researchers whose expertise I trust the most, many, though not all, have updated in the direction of “maybe we should start worrying.” (Related: Eliezer Yudkowsky’s There’s No Fire Alarm for Artificial General Intelligence.)
Who knows how much of the human cognitive fortress might fall to a few more orders of magnitude in processing power? I don’t—not in the sense of “I basically know but am being coy,” but really in the sense of not knowing.
To be clear, I still think that by far the most urgent challenges facing humanity are things like: resisting Trump and the other forces of authoritarianism, slowing down and responding to climate change and ocean acidification, preventing a nuclear war, preserving what’s left of Enlightenment norms. But I no longer put AI too far behind that other stuff. If civilization manages not to destroy itself over the next century—a huge “if”—I now think it’s plausible that we’ll eventually confront questions about intelligences greater than ours: do we want to create them? Can we even prevent their creation? If they arise, can we ensure that they’ll show us more regard than we show chimps? And while I don’t know how much we can say about such questions that’s useful, without way more experience with powerful AI than we have now, I’m glad that a few people are at least trying to say things.
But one more point: given the way civilization seems to be headed, I’m actually mildly in favor of superintelligences coming into being sooner rather than later. Like, given the choice between a hypothetical paperclip maximizer destroying the galaxy, versus a delusional autocrat burning civilization to the ground while his supporters cheer him on and his opponents fight amongst themselves, I’m just about ready to take my chances with the AI. Sure, superintelligence is scary, but superstupidity has already been given its chance and been found wanting.
Speaking of superintelligences, I strongly recommend an interview of Ed Witten by Quanta magazine’s Natalie Wolchover: one of the best interviews of Witten I’ve read. Some of Witten’s prouncements still tend toward the oracular—i.e., we’re uncovering facets of a magnificent new theoretical structure, but it’s almost impossible to say anything definite about it, because we’re still missing too many pieces—but in this interview, Witten does stick his neck out in some interesting ways. In particular, he speculates (as Einstein also did, late in life) about whether physics should be reformulated without any continuous quantities. And he reveals that he’s recently been rereading Wheeler’s old “It from Bit” essay, because: “I’m trying to learn about what people are trying to say with the phrase ‘it from qubit.'”
I’m happy to report that a group based mostly in Rome has carried out the first experimental demonstration of PAC-learning of quantum states, applying my 2006 “Quantum Occam’s Razor Theorem” to reconstruct optical states of up to 6 qubits. Better yet, they insisted on adding me to their paper!
I was at Cornell all of last week to give the Messenger Lectures: six talks in all (!!), if you include the informal talks that I gave at student houses (including Telluride House, where I lived as a Cornell undergrad from 1998 to 2000). The subjects were my usual beat (quantum computing, quantum supremacy, learnability of quantum states, firewalls and AdS/CFT, big numbers). Intimidatingly, the Messenger Lectures are the series in which Richard Feynman presented The Character of Physical Law in 1964, and in which many others (Eddington, Oppenheimer, Pauling, Weinberg, …) set a standard that my crass humor couldn’t live up to in a trillion years. Nevertheless, thanks so much to Paul Ginsparg for hosting my visit, and for making it both intellectually stimulating and a trip down memory lane, with meetings with many of the professors from way back when who helped to shape my thinking, including Bart Selman, Jon Kleinberg, and Lillian Lee. Cornell is much as I remember it from half a lifetime ago, except that they must’ve made the slopes twice as steep, since I don’t recall so much huffing and puffing on my way to class each morning.
At one of the dinners, my hosts asked me about the challenges of writing a blog when people on social media might vilify you for what you say. I remarked that it hasn’t been too bad lately—indeed that these days, to whatever extent I write anything ‘controversial,’ mostly it’s just inveighing against Trump. “But that is scary!” someone remarked. “You live in Texas now! What if someone with a gun got angry at you?” I replied that the prospect of enraging such a person doesn’t really keep me awake at night, because it seems like the worst they could do would be to shoot me. By contrast, if I write something that angers leftists, they can do something far scarier: they can make me feel guilty!
I’ll be giving a CS colloquium at Georgia Tech today, then attending workshops in Princeton and NYC the rest of the week, so my commenting might be lighter than usual … but yours need not be.
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