A Retiree Discovers an Elusive Math Proof (2017) | Hacker News Reader

A Retiree Discovers an Elusive Math Proof (2017)

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118 pointsForFreedom41 comments

>“He had formulas that enabled him to pull off his magic,” Pitt said. “And I didn’t have the formulas.”

The more I do pure mathematics, the more I realize just how important these kinds of insights are. Very often, solving a theoretical problem involves two key ingredients:

1. Rewriting your problem in a particular way, so that it is amenable to a certain suite of methods/looks like known results.

2. Apply a key bit of knowledge gleaned from intuition. This is unrelated to the formal way the problem was written down.

Sometimes, showing your intuition is true formally actually takes a lot of work. And for some proofs, looking at the problem a particular way makes the solution obvious on its own, with no need for a step 2. And other times, like this, all the technical tools in the world are no match for just knowing the right piece of information.

I think many highly productive mathematicians are very good at organizing formulas and facts in such a way that they can be retrieved easily from memory based on context. Maybe something analogous to a hash function from computer science.

Some mathematicians seem to index facts based on geometric images, others seem to be more inclined to symbolic or algebraic statements. Whatever the representation, when confronted with a new mathematical situation they then scan quickly for matches to various aspects of the problem at hand.

Maybe to some degree my observation here is obvious. But I thought a lot about it while I was in grad school studying a book called Geometric Measure Theory by Herbert Federer. That book is enormous, and full of highly intricate technical proofs that require pulling together a large number of detailed technical facts.

The book is also very highly structured, and that led me to conclude that the text likely mirrored how Federer organized this information in his head. It reads like code for a complex but cleanly architected software system, and that's a big part of what led me from math to software development.

are you under the impression the people write books like that without referring to sources themselves? because they don't. I doubt any one knows all the proofs in a book like by heart or could reconstruct them without references for key facts.

No, I was never under that impression. I once had a discussion about the creation of the book with one of Federer's students who had also helped proofread it. The book was essentially an outgrowth of his personal and course notes, since of course he couldn't keep all this in his head.

What he likely did have in his head was an index into the contents, that's the crux of my observation. If I am very good at organizing my workshop, I can quickly grab the tools and materials needed for a particular task without breaking my flow of thought. Same basic principle applies to mathematicians and other intellectual workers, just as it does with physical trades.

People of that calibre are quite rare but they do exist. I've seen final year undergraduate courses pulled off without the lecturer once having to refer to notes. All proofs were completed in exacting detail on the whiteboard.

Sure, but those math profs have probably taught the same course 20+ times. Going through material that many times will permanently burn it into your brain.

Absolutely. And in mathematics, advanced structures and theorems are built up layers by layer upon more elementary material. A professor who has mastered presentation of undergraduate material on a topic also likely teaches a graduate course on it, and mentors students on it, and does research on it.

They can talk about their chosen topic at many levels to many different audiences, from general audience (who may provide funding to them), high school students (outreach and recruiting), university students, and peers. This flexibility is an important part of being a very successful mathematician, and you have to burn it into your brain to reach that level of fluency.

I took a philosophy class with a professor who had taught it about that many times. Talked to a guy who had taken it before me, he said that the prof has literally word-for-word memorized certain parts of the lectures because he's figured out and internalized the wording he thinks is best. Mathematicians can certainly do the same.

also they review the lecture before hand just like anyone delivering a speech does

A similar realization is that most algorithms/data structures problems posed in software engineering interviews are all about imposing the right mathematical formalisms.

If you correctly infer the _structure_ of the problem, then you're going to have an easy time solving it. If not, you'll use a great lot of time hunting for a fruitful angle of attack.

Oh please let’s not glorify those simple trick questions to be anywhere near as hard or require the degree of intuition that OP or theoretical mathematicians work on.

75% of interview questions can be solved with some form of BFS/DFS and they’re largely a hazing ritual these days. I’m saying this as someone who recently got offers from 4 of the big 5 companies

Something only takes “hard intuition” the first time it comes up. For instance, when these data structures were new, inventing them took hard intuition. The second time the same trick is used, it becomes a ‘clever application of an obscure idea’ to a new problem.

Then once the same intuitive leap has been used to solve many different problems, and gets taught in school, it becomes a “simple trick”, or even just a “standard technique”.

If this same method is useful for solving a wide range of structurally similar problems, it will go through that process, and eventually become thought of as a “simple trick”. If it is only used as a one-off for this particular proof, it will remain one man’s genius idea.

I've worked through various exams and research problems leading to a math PhD, and I see the similarity. I fail to see how someone articulating an observation about that "glorifies" the interview questions.

I've heard students complain that graduate qualifying exams are a form of hazing for people hoping to become pure mathematicians, and although I don't entirely agree with that sentiment, they do play a similar role in weeding out people based on preparation rather than ability to generate deep, novel insights.

\tangent does the formal proof make sense to a mathematician (as in, can they see it)?

Or is it more the hex of assembly of to the high level language of the intuition, in the semse that they can verify it, but not necessarily see it?

This is from 2017, previous discussion here: https://news.ycombinator.com/item?id=13977554

It would be nice if the title named the proof. Math is a giant field, and very few HNers are mathematicians or interested in any particular area of mathematics, so it would be helpful to know what the general topic is without clicking on the link and reading a few paragraphs.

"A Retiree Discovers an Elusive Math Proof of the Gaussian Correlation Inequality (2017)"

I'm sorry to be mean, but this title is stupid and condescending. He didn't use Word to solve the problem, he used Word to write the paper about the solution. It really has nothing to do with how the problem was actually solved. Might as well claim he "used Windows" to solve the problem.

"The authors don't use TeX" is #1 of Scott Aaronson's Ten Signs a Claimed Mathematical Breakthrough is Wrong

https://www.scottaaronson.com/blog/?p=304

For context, the submission title was "This 67-year-old retiree solved a math problem–using Microsoft Word". Thankfully, it's been fixed.

Ahh, thank you. I was very confused

It seems like a stretch to call this a big discovery in the math world. Even if it had been published in a top journal etc, it would be unlikely to be heralded as a major achievement.

Is it being characterized as a major discovery somewhere in this article? I see it described as an elusive problem, and it's claimed that the solution is a major paper worthy of publication in Annals of Statistics, but mostly it just comes across as an interesting story about how this proof came to be.

(regarding the current title of this submission, in case it gets changed:)

>This 67-year-old retiree solved a math problem–using Microsoft Word

What does Microsoft Word have to do with this? The fact that the document was typeset in Microsoft Word instead of LaTeX does not really sound remarkable.

It's just blatant clickbait :(

> What does Microsoft Word have to do with this?

It's an indication that the person who solved it is an amateur, that's all.

No, he's not an amateur but a retired statistian. And the fact that LaTeX is the standard for DIY typesetting in academia nowadays has nothing to do with your competence as a mathematician, or the rigour of a proof published as a Word document. Likewise, it doesn't matter if you work with pen and paper or with pencil and paper.

This title is absurd.

Well it got me to click on it. Which in the end I’m pretty happy about; it was a very interesting article. Can clickbait be justifiable if the end product is good?

You're opening a can of worms there.

Which is pretty thin. I wouldn't consider mathematicians of the pre-word-processor era amateurs.

Not just that, but that he did it with rudimentary tools.

'Amateur' would seem to conflict with 'retiree.'

Not really. You can be an expert in one field and an amateur in another.

The word retiree is clickbait too. It hides the fact that he is a (retired) professional statistician.

The article is not about the math problem itself, it's also about MS Word starting to be used and accepted alongside LaTeX.

EDIT: I am wrong, I misunderstood the article

Not sure how you came to that conclusion. The article's actual title doesn't mention Word, and it seems to be a minor point in the article. It even goes on to say:

>> Richards notified a few colleagues and even helped Royen retype his paper in LaTeX to make it appear more professional.

I've re-read the article and you're right. I misunderstood the "Word is getting around" part. Sorry

This is based on experience, i used to teach math. (~4000)

And i found it easier to teach math to people whoes father, grandfather, great grandfather all had masters in math.

So, i wonder if mathematical abilities are in genes and gene function changes when you bring a person with such genes into a math intense environment.

From observation, some of the people I know who were sharpest at learning new technical subjects and solving hard technical problems were way behind as undergraduates compared to folks who were not as good at problem solving but had been steeped in a technical culture from a young age, and as a result the newcomers had to work a lot harder to catch up.

“Easy to teach” comes from understanding your vocabulary and references, having seen similar material before, not being confused by severe misconceptions, coming in with similar mindset, etc., not necessarily from being the best at new research (or whatever other real work task).

Someone who is a 4th generation mathematician is going to be completely comfortable talking about mathematical topics in casual conversation, irrespective of any genetic differences.

Could it just possibly be the fact they've been raised in environment that encourages the thought processes necessary to understand more "abstract" math?

Phrased differently, they've been given somewhat "institutional" tools necessary to accomplish these types of goals?

Not sure why you would even remotely assume genetics over just skills being passed down..? Pre war if you look at careers in census everyone used to do what their parents did. Its because its what they taught you!

> Not sure why you would even remotely assume genetics over just skills being passed down..?

There were also orphans who had never seen their parents or grandparents.

When genes are responsible for being lactose tolerate, why is it hard to hypothesise that only some people benefit from being raised in a math intense environment and not others?

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