A random collection of things that may be of interest:
- September 17 and 18 I’ll be at the How the Light Gets In Festival in London, participating in discussions of the relation of math and physics, and theories of everything. I’m looking forward to the festival, which sounds like fun, and to spending some time in London. A week or so later, I’ll be in Oxford, attending the Clay Research Conference as well as a Physics from the Point of View of Geometry workshop in honor of Graeme Segal’s 80th birthday.
- I’ve been spending the summer trying to write up some details of the ideas I’ve been working on, specifically the claim that the geometry of spinors in four dimensions allows one to think of one of the SU(2)s in the Euclidean Spin(4) symmetry as an internal symmetry. Still learning more about how this works, hope to have something ready to publicize within the next month or so.
- For rest and relaxation I’ve been learning a bit more about various Langlands-related topics. The talks from the IHES summer school are mostly well-worth watching. Also very highly recommended are David Ben-Zvi’s lectures on The Langlands Program as Electric-Magnetic Duality given a couple weeks ago at a workshop in Cambridge.
- Still trying to finish reading Récoltes et Semailles and decide whether to write something here about this bizarre and fascinating document. If you want to read this yourself, Mateo Carmona has a freely available transcription here.
- There an interesting conversation about Ricci flow between my Columbia colleagues John Morgan and Richard Hamilton available here.
- Sometimes it takes great self-control to avoid responding to things I see on Twitter. In the case of a recent exchange between Noah Smith and various people defending string theory. I couldn’t help myself and started writing something, then soon hit the character limit. This returned me to sanity as I realized that trying to have an intelligible discussion in the twitter format about anything complicated is just absurd.
The gist of a lot of the discussion was that even string theory defenders now admit it was an overhyped failure as a “theory of everything”, but they then come up with new, improved hype. One argument seems to be that string theory has led to new developments in hype about black holes (for these, Scientific American has you covered here).
- Today on Twitter Sabine Hossenfelder explains her current academic employment situation (no permanent position, latest grant application denied.) She’s a very unusual case, and has a successful new book and other ventures that to some degree can replace a standard academic income. For everyone though, the way academic jobs in theoretical physics work, if you decide you want to pursue topics other than very conventional ones that a group is already working on, you’re going to have a very hard time. Getting older and having a life also tends to be inconsistent with pursuing the very few opportunities that might come up.
I’m tired of seeing string theorists hijacking other fields and pretending their failed methods and ideas are revolutionizing those fields. It’s remarkable, these people are not going to stop, it seems. And they get a lot of press! When is this nightmare going to stop?!
Meanwhile, in actual black hole news, people like Klainerman have been working on the really, really hard problems, like Kerr stability, and recently they finally proved an amazing result, with actual relevance to our physical picture about the final state of real black holes at late times.
At least Quanta covered the news: https://www.quantamagazine.org/black-holes-finally-proven-mathematically-stable-20220804/
There are some great talks by him in youtube on these topics as well.
This isn’t the first time Noah Smith has tweeted a horrendously ignorant opinion, then mocked those pointing out his ignorance as being sensitive and butt-hurt, and then deleting the tweet to hide evidence of his ignorance.
Something that struck me as bizarre in that thread was that string theory was being defended as a “simple toy model” for describing condensed matter systems, while simultaneously also being admitted as far removed from the actual realistic physics of said systems. String theory was considered a “good starting point” because it’s “easy to work with,” not because it’s actually relevant to the physics under consideration. String theorists and condensed matter physicists certainly have different standards for what constitutes a “simple toy model”.
FYI, it’s perfectly acceptable twitter etiquette to comment with a multi-tweet thread. You need not limit your entire reply to a single tweet.
I don’t think his original tweet was “horrendously ignorant”. It’s hard to overemphasize the damage of all sorts that decades of outrageous hype, failure, and refusal to acknowledge failure have done (and continue to do) to important parts of physics. Yes, the case for linking this to less progress in “applied quantum mechanics” wasn’t very good, and I think it’s to his credit that he realized this and deleted the original tweet.
On the other hand, all the people who piled on with ridiculous hype about string theory’s supposed successes are the sorts who never will admit that their claims are wrong. That’s just one reason why it would have been a waste of time to engage with them.
I’m well aware one can chain together tweets, but that’s awkward. Twitter’s design seems intended to make thoughtful discussion and engagement with other people’s arguments difficult, while encouraging randoms short bursts of stupidity.
I’d be interested in what you got from a reading of R&S. I’ve myself tried to find time to read the 2-volume, but it’s been very difficult, and reading it is not the easiest of things, because it seems like a lot of what he wrote came from some deep thinking, which requires the reader to pause and meditate on some points.
Writing something about this is a daunting prospect, it’s huge unedited mix of the wonderful and deep with the paranoid and tedious.
Probably a good idea to keep in mind that to some extent Grothendieck’s intended audience was mathematicians in his field (algebraic geometry). The more you know about that field and what was going on in it during the years from the mid-50s to the mid-80s, the more you’re likely to make sense of parts of it. At some points this gets very frustrating: after he goes on for dozens of pages about how terrible it was that people other than Deligne didn’t understand and appreciate his (unpublished) ideas about weights and the “yoga” of motives, you really wish he instead had spent the time writing out an explanation of those ideas.
More multiverse mania:
The Guardian: Cosmologist Laura Mersini-Houghton: ‘Our universe is one tiny grain of dust in a beautiful cosmos’.
Very sad to know about Sabine Hossenfelder. There is no value to popular fame, which is much more important writing another stupid paper, in mainstream academia.
PS: I am a string theorist.