Blog Profile / Shtetl-Optimized

Filed Under:Academics / Physics
Posts on Regator:196
Posts / Week:0.5
Archived Since:December 19, 2008

Blog Post Archive

Talk, be merry, and be rational

Yesterday I wrote a statement on behalf of a Scott Alexander SlateStarCodex/rationalist meetup, which happened last night at MIT (in the same room where I teach my graduate class), and which I’d really wanted to attend but couldn’t.  I figured I’d share the statement here: I had been looking forward to attending tonight’s MIT SlateStarCodex meetup as I […]

G. Phi. Fo. Fum.

Earlier today, I was tipped off to what might be the theoretical computer science result of the decade.  My source asked me not to break the news on this blog—but since other theory bloggers (and twitterers) are now covering the story, I guess the graph is out of the Babai. According to the University of Chicago’s theory seminar calendar, […]

A breakthrough on QMA(2)

Last night, Martin Schwarz posted a preprint to the arXiv that proves the new complexity class containment QMA(2) ? EXP.  (See also his brief blog post about this result.)  Here QMA(2) means Quantum Merlin-Arthur with two Merlins—i.e., the set of languages for which a “yes” answer can be witnessed by two unentangled quantum states, |???|??, on polynomially […]

Ordinary Words Will Do

Izabella Laba, a noted mathematician at the University of British Columbia, recently posted some tweets that used me as a bad, cautionary example for how “STEM faculty should be less contemptuous of social sciences.”  Here was the offending comment of mine, from the epic Walter Lewin thread last fall: [W]hy not dispense with the empirically-empty […]

Six announcements

I did a podcast interview with Julia Galef for her series “Rationally Speaking.”  See also here for the transcript (which I read rather than having to listen to myself stutter).  The interview is all about Aumann’s Theorem, and whether rational people can agree to disagree.  It covers a lot of the same ground as my recent post on the same […]

Bell inequality violation finally done right

A few weeks ago, Hensen et al., of the Delft University of Technology and Barcelona, Spain, put out a paper reporting the first experiment that violates the Bell inequality in a way that closes off the two main loopholes simultaneously: the locality and detection loopholes.  Well, at least with ~96% confidence.  This is big news, not only because of the […]

Ask Me Anything: Diversity Edition

With the fall semester imminent, and by popular request, I figured I’d do another Ask Me Anything (see here for the previous editions).  This one has a special focus: I’m looking for questions from readers who consider themselves members of groups that have historically been underrepresented in the Shtetl-Optimized comments section. Show More Summary

D-Wave Open Thread

A bunch of people have asked me to comment on D-Wave’s release of its 1000-qubit processor, and a paper by a group including Cathy McGeoch saying that the machine is 1 or 2 orders of faster (in annealing time, not wall-clock time) than simulated annealing running on a single-core classical computer.  It’s even been suggested […]

6-photon BosonSampling

The news is more-or-less what the title says! In Science, a group led by Jeremy O’Brien at Bristol has now reported BosonSampling with 6 photons, beating the previous record of 4 photons achieved a few years ago by the Walmsley group at Oxford (as well as the 3-photon experiments done by groups around the world).  Humorously, […]

Jacob Bekenstein (1947-2015)

Today I learned the sad news that Jacob Bekenstein, one of the great theoretical physicists of our time, passed away at the too-early age of 68. Everyone knows what a big deal it was when Stephen Hawking discovered in 1975 that black holes radiate.  Bekenstein was the guy who, as a grad student in Princeton […]

Common Knowledge and Aumann’s Agreement Theorem

The following is the prepared version of a talk that I gave at SPARC: a two-week high-school summer program about applied rationality held in Berkeley, CA for the past two weeks.  I had a wonderful time in Berkeley, meeting new friends and old, but I’m now leaving to visit the CQT in Singapore, and then to […]

Introducing some British people to P vs. NP

Here’s a 5-minute interview that I did with The Naked Scientists (a radio show syndicated by the BBC, and no, I’m not sure why it’s called that), explaining the P vs. NP problem.  For readers of this blog, there won’t be anything new here, but, well … you might enjoy the rest of the hour-long programme [sic], which also includes […]

Quantum query complexity: the other shoe drops

Two weeks ago I blogged about a breakthrough in query complexity: namely, the refutation by Ambainis et al. of a whole slew of conjectures that had stood for decades (and that I mostly believed, and that had helped draw me into theoretical computer science as a teenager) about the largest possible gaps between various complexity […]

Celebrate gay marriage—and its 2065 equivalent

Yesterday was a historic day for the United States, and I was as delighted as everyone else I know.  I’ve supported gay marriage since the mid-1990s, when as a teenager, I read Andrew Hodges’ classic biography of Alan Turing, and burned with white-hot rage at Turing’s treatment.  In the world he was born into—our world, […]

“Can Quantum Computing Reveal the True Meaning of Quantum Mechanics?”

I now have a 3500-word post on that question up at NOVA’s “Nature of Reality” blog.  If you’ve been reading Shtetl-Optimized religiously for the past decade (why?), there won’t be much new to you there, but if not, well, I hope you like it!  Comments are welcome, either here or there.  Thanks so much to Kate Becker at NOVA for […]

FCRC Highlights

By popular request, here are some highlights from this week’s FCRC conference in Portland, Oregon: The edit distance between two strings means the minimum number of insertions, deletions, and replacements needed to convert one string to the other: for example, SHTETL and SHETLAND have an edit distance of 4.  Edit distance has major, obvious applications […]

A query complexity breakthrough

Lots of people have accused me of overusing the word “breakthrough” on this blog. So I ask them: what word should I use when a paper comes out that solves not one, not two, but three of the open problems I’ve cared about most for literally half of my life, since I was 17 years […]

97% environmentalist

I decided to add my name to a petition by, as of this writing, 81 MIT faculty, calling on MIT to divest its endowment from fossil fuel companies.  (My co-signatories include Noam Chomsky, so I guess there’s something we agree about!)...Show More Summary

Can blog posts nourish the soul? Scott A. (alas, not me) as existence proof

Reading the essays and speculative fiction of Scott Alexander, as they’ve grown in awesomeness even just within the past half-year, has for me been like witnessing the birth of a new Asimov.  (For more Alexandery goodness, check out Universal Love, Said the Cactus Person.)  That this nerd-bard, this spinner of stupid Internet memes into reflections on eternity, […]

The End of Suffering?

A computer science undergrad who reads this blog recently emailed me about an anxiety he’s been feeling connected to the Singularity—not that it will destroy all human life, but rather that it will make life suffering-free and therefore no longer worth living (more Brave New World than Terminator, one might say). As he puts it: This […]

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