After 20 years, math couple solves major group theory problem

1 day ago (quantamagazine.org)

"There was a risk that such a single-minded pursuit of so difficult a problem could hurt her academic career, but Späth dedicated all her time to it anyway."

I feel like this sentence is in every article for a reason. Thank goodness there are such obsessive people and here's a toast to those counter-factuals that never get mentioned.

  •   > I feel like this sentence is in every article for a reason.
    

    Breakthroughs, BY DEFINITION, come from people going against the grain. Breakthroughs are paradigm shifts. You don't shift the paradigm by following the paradigm.

    I think we do a lot of disservice by dismissing the role of the dark horses. They are necessary. Like you suggest, there are many that fail, probably most do. But considering the impact, even just a small percentage succeeding warrants significant encouragement. Yet we often act in reverse, we discourage going against the grain. Often with reasons about fear of failure. In research, most things fail. But the only real failure is the ones you don't learn from (currently it is very hard to publish negative results. Resulting it not even being attempted. The system encourages "safe" research, which by its nature, can only be incremental. Fine, we want this, but it's ironic considering how many works get rejected due to "lack of novelty")

    • > Breakthroughs, BY DEFINITION, come from people going against the grain. Breakthroughs are paradigm shifts.

      This is wrong. It's not inherent in the meaning of the word "breakthrough" that a breakthrough can occur only when someone has gone against the grain, and there are countless breakthroughs that have not gone against the grain. See: the four-minute mile; the Manhattan Project; the sequencing of the human genome; the decipherment of Linear B; research into protein folding. These breakthroughs have largely been the result of being first to find the solution to the problem or cross the theshold. That's it. That doesn't mean the people who managed to do that were working against the grain.

      > Yet we often act in reverse, we discourage going against the grain. Often with reasons about fear of failure.

      I don't know which "we" you're referring to, but just about everybody would agree with the statement that it's good to think creatively, experiment, and pursue either new lines of inquiry or old lines in new ways, so, again, your claim seems clearly wrong.

      If you're discussing just scientific research, though, sure, there are plenty of incentives that encourage labs and PIs to make the safe choice rather than the bold or innovative choice.

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    • > Often with reasons about fear of failure.

      If that were it, I would agree.

      But I don't agree. I think people who discourage going against the grain are more fearful of the loss of economic input. It's unproductive to do something you know will fail; it's very expensive to encourage that failure.

    • Paradigm shifts require an accumulation of mundane experiments that present contradictions in a model. The renegade hacker isn't enough.

    • > Breakthroughs, BY DEFINITION, come from people going against the grain.

      They are what Gladwell calls, in "David and Goliath", being unreasonable in the face of so-called "prevailing wisdom".

  • I want financial independence for the sole reason that I can work on interesting problems like this without any outside nagging or funding issues from anyone else (there might still be some judgment, but I can ignore that).

    Personally I think governments should fund more moonshot solo or small team efforts because high risk / high reward pays off when you reduce the variance by spreading it out over so many people. But it looks like we’re going headstrong the other direction in terms of funding in the U.S. right now, so I’m not optimistic.

    •   > I want financial independence for the sole reason that I can work on interesting problems like this without any outside nagging or funding issues from anyone else
      

      Ditto. This is literally the only desire I have to be wealthy. It is not about having nice things, a nice house, or any of that. It is about letting me do my own research.

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    • I'm a Swedish game developer and I feel exactly the same way. I have my dream games I work on every now and then making very little slow progress. My wildest dream would be just being able to dedicate myself to it full time. But, there are bills to pay.

    • Given what universities charge, they should more than be able to cover comfortable salaries for all researchers so they never need to worry about going broke. Tenure is a very useful tool!

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  • I worked at a pro audio company where one guy spent 5 years on a power supply. It succeeded, and I always appreciated the management for supporting him.

    • Do recall the specific problem he was trying to solve?

      It's amazing to me how much thought and work has gone into the seemingly trivial things we encounter on a daily basis.

      I think of this every time I see a blue LED. Or a rice cooker!! So easy to take for granted.

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  • There are tens of millions of people doing a repetitive work every day, instead of being entrepreneurs. Just let them be, not everybody needs to dedicate their existence to maximizing their career opportunities, at any level.

    •   > Just let them be
      

      As someone who's research goes against the grain, I just request the same. I have no problem with people maintaining the course and doing the same thing. In fact /most/ people should probably be doing this. BUT the system discourages going of course, exploring "out of bounds." The requests of these people have always been "let me do my thing."

      Just make sure "let them be" applies in both directions

  • Unfortunately the average persons hatred of autistic or nerdy people implies that many believe the world would be a better place if “obsessive types” didn’t exist.

    Hans Asperger could only save his Austic children from nazi death camps by convincing the nazis that they had value to produce rockets and bombs.

    It’s quite remarkable that the USA is so advanced given how deep and ruthless our anti-intellectualism goes.

    • "the average persons hatred of autistic or nerdy people"

      This is a wildly inaccurate picture of the average person. I don't even think this is true of 10% of people.

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    • US intellectualism is patchy. Sure a lot of people are not into it but on the other hand you probably have more well paid academic posts than any other country.

    • Probably the most powerful man in the world right now openly self-identifies as autistic. Obviously there are very many autistic people who get treated very badly, but I don't think it's reasonable to say that the average person "hates" autistic people.

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    • If anything autistic/nerdy people are lionized these days with tons of people larping as them online, claiming they are autistic because they sometimes feel awkward at a social event.

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    • What are you talking about, why do you think that autistics are treated better in Europe, Africa, Asia? Also, people do not "hate" them, people in general hate everybody, don't play the victim

    • Isn't it basically the same? Nazi Germany in 1934 was relatively advanced, too.

      I think the difference is^W was that USA celebrated it in a Homer Simpson kind of "Ha ha! NERDS!" way, while meth-Hitler was like "let's sterilize them but try to extract math from them to... (whatever batshit goal)"

      Anti-intellectualism seems to be a thing when the intellectual/moderately-competent people have already brought success. (Until then it's more like anti-witchcraft, or whatever...)

> When the couple announced their result, their colleagues were in awe. “I wanted there to be parades,” said Persi Diaconis (opens a new tab) of Stanford University. “Years of hard, hard, hard work, and she did it, they did it.”

That sort of positive support was one of the elements I really liked in working on combinatorial problems. People like Persi Diaconis and D.J.A. Welsh were so nice it makes the whole field seem more inviting.

  • All our acts are butterfly wing beats that influence those with whom we interact, for either good or ill. And those waves resonate back within our being as happiness or its opposite, depending on our intentions and actions.

    "Positive vibration, yeah." --Bob Marley

So what the McKay conjecture is saying is this.

Suppose I'm interested in representing a Group as matrices over the complex numbers. There are usually many ways of doing this. Each one of them has a so-called character, which is like fingerprint of such a representation.

Along another line, it has been known that all groups contain large subgroup having an order which is a power of a prime--call it P. This group in turn has a normalizer in which P is normal--call it N(P).

The surprising thing is that the number of characters of G and of N(P)--which is is only a small part of G--is equal.

*technical note in both cases we exclude representation the degree of which is a multiple of p.

It’s interesting that the conjecture was proven via case by case analysis, with each case demanding different techniques. It’s almost a coincidence that all finite groups have this property, since each group has the property because of a different “reason”.

But the article says that mathematicians are now searching for a deeper “structural reason” why the conjecture holds. Now that the result is known to be true, it’s giving more mathematicians the permission to attack it seriously.

  • I don't think that is that unusual in group theory proofs to be honest. You often break things down into related things and then prove for each collection of related things. And some of those proofs might be straightforward and some might be open problems for years requiring much more advanced techniques.

Hah, serendipity: I was reading the Groups part of the Infinite Napkin after it was posted on HN recently. I understand the definitions, etc. but still haven’t grasped the central importance of groups.

For example, article says there are 50 groups of order 72 (chatGPT says there are 50 non-Abelian, 5 Abelian), this seems to be an important insight but into what?

  • Don't listen to ChatGPT. There are 44 non-abelian and 6 abelian groups of order 72. I wouldn't say these particular numbers are terribly important, but they are correct.

    • Definitely don't use ChatGPT to try to learn about something you have no knowledge of. It's impossible to separate the bullshit from the truth if you don't already have some foundation in the field, and chatbots often try to sneak some bullshit in there.

    • Don't listen to ChatGPT.

      As someone "junior programmer" , I think I should just keep this information . Many times I have tried to not use chatgpt. but its just so lucrative.

      I really need better control of myself. Going to block chatgpt at a dns level.

  • Groups are important because they are the algebraic way to describe symmetry: if you have some operation that leaves a thing invariant (e.g. rotating an equilateral triangle so that a vertex lands on where another started), then the operation is invertible and the inverse leaves the thing invariant. You can compose such operations and the composition will still be invariant. The identity function always leaves everything invariant. So your symmetry operations form a group.

    Slightly trickier is that every group is a set of symmetry operations for something. So groups exactly capture the idea of symmetry. To a mathematician, "group" and "symmetries" are synonymous.

    Finite groups can be interesting as the symmetries of e.g. molecules (e.g. rotating atoms around onto each other), which can tell you something about molecular structure, energy levels, spectra, bonding potential, etc. Infinite groups appear in physics (e.g. the laws of physics are the same when you rotate or translate your coordinates by arbitrary amounts). Symmetry also comes up as a way to study other mathematical objects, and mathematicians might just want to know what all possible groups look like.

  • I've only taken three (undergrad) classes involving groups so I'm far from an expert but my feeling is that their underlying structure is a bit like prime numbers.

    Nobody bothers explaining why the primes are spaced like they are, rather people explain other phenomena by pointing out that certain things about it are prime or not.

    For instance, there's this thing about having a nice neat formula for factoring second degree polynomials (the quadratic formula). One also exists for cubics and quartics (though they don't usually have you memorize these) but none exists for quintics. It took mathematicians a while to prove that such a thing doesn't exist (how to prove a negative?) but they managed it by arguing that all such things have an underlying finite group smaller than a certain size and look, we've listed them here, and there's no such group corresponding to a quintic formula, therefore there is no quintic formula.

    So they're useful as a sort of primordial complexity that can be referenced without extensive explanation since properties about the small ones can be checked by hand. And as it turns out, quite a lot of things form groups if you bother you look at them that way.

    • > Nobody bothers explaining why the primes are spaced like they are

      I take it that means you also haven't taken (m)any number theory classes then ;-). Because people wildly care about that.

      This is in a sense the background of another well-known conjecture, the Riemann conjecture...

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  • Many mathematical structures are groups so understanding them helps you get insight into the concrete situation you are trying to solve. For example is the problem I am seeing abelian? If so then it must look like X or Y.

Damn. That's some dedication. I really like the personal story, therein. You don't always see that, in STEM stuff.

I hope that their relationship deals well with the new reality, now that their principal goal has been achieved.

  • I think experts in all kinds of fields should write more about their thinking process. Just showing final result often feels like it was easy for them and discourages other from even attempting to understand and contribute. Especially in mathematics, the ideas are simple (they have to be because no one would be summing infinite series in their head like Ramanujan) but they are hidden behind lot of symbolic jargons.

I started "Prime Target" on Apple TV last night and I knew the premise of this story sounded familiar! The protagonist is obsessed over a prime number problem.

Unrelatedly, I'd be curious what this couple thinks about using AI tools in formal math problems. Did they use any AI tools in the past 2 years while working on this problem?

This is a terrific article. It led me to a couple of hours tracking articles about related efforts, not the least of which was John Conway's work.

Mind you, my math is enough for BSEE. I do have a copy of one of my university professor's go-to work books: The Algebraic Eigenvalue Problem and consult it occasionally and briefly.

How do these kinds of advancements in math happen? Is it a momentary spark of insight after thinking deeply about the problem for 20 years? Or is it more like brute forcing your way to a solution by trying everything?

  • My experience from proving a moderately complicated result in my PhD was that it's neither. There wasn't enough time to brute force by trying many complete solutions, but it also wasn't a single flash of insight. It was more a case of following a path towards the solution based on intuition and then trying a few different approaches when getting stuck to keep making progress. Sometimes that involves backtracking when you realize you took a wrong path.

    • Yeah agreed - there are actually many, smaller flashes of insight, but most of them don't lead to anything. I once joked that you could probably compress all the time I was actually going in the right direction in my PhD down to about a month or two. That's a bit glib, often seeing why an approach fails gives you a much better idea of what a proof 'has to look like' or 'has to be able to overcome'. But many months of my PhD were working on complete dead-ends, and I certainly had a few very dark days because of that. Research math takes a lot of perseverance.

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  • In this case, a ton of progress had already been made. The conjecture had been proved in some cases, reduced to a simpler problem in others. This couple went the last mile of solving the simpler problem in some particularly thorny cases.

    You're really standing on the shoulders of giants when you rely on the classification of finite simple groups.

    • You're really standing on the shoulders of giants when you rely on the classification of finite simple groups.

      Giants whose work has (dirty little secret) never truly been verified. The proof totals about 10,000 pages. At the end of the effort to prove it there were lots of very long papers, with a shrinking pool of experts reviewing them. There have been efforts to reprove it with a more easily verified proof, but they've gone nowhere.

      Hopefully, the growing ease of formalization will lead to a verification some day. But even optimistically that is still a few years out.

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  • The structure of DNA was seen in a vision in James Watson's dream. Some say it's subconscious problem solving and I think most down to earth people agree with that, but some less down to earth people will absolutely attribute it to god (I'm in the latter). If we were to entertain a silly proposition, something in the universe could just move our story along, all of a sudden. These paradigm shifts just seem to appear.

    • > The structure of DNA was seen in a vision in James Watson's dream

      I believe this is apocryphal. Watson likely said this because he stole Rosalind Franklin's research.

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    • Subconscious problem solving is definitely a thing as far as I'm concerned.

      It's happened several times that I struggled with a bug for hours, then suddenly came up with a key insight during the commute home (or while taking a shower or whatnot), while not actively thinking about the problem. I can't explain this any other way than some kind of subconscious "brainstorming" taking place.

      As a side note, this doesn't mean the hours of conciously struggling with the problem were a waste. I bet that this period of focus on the problem is what allows for the later insights to happen. Whether it's data gathering that alows the insights to happen, or even just giving importance to the problem by focusing on it. Most likely it's both.

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With the right photo, this could be an Onion headline poking fun at lonely math nerds.