I don't know who needs to hear this, but sharpen your kitchen knives. It makes cutting stuff easier.

@neauoire I’m still waiting for “Falsehoods programmers believe about peoples’ accessibility to technology.”

Turns out it’s pretty hard to do two-factor authentication when you’re trying to pay a utility bill from a public library computer.

Procaffinating: To delay or postpone action; put off doing something until you've had coffee.


What's the strangest thing you've ever found in a book?

Here's my story...

About 20 years ago or so, I was at a Salvation Army auction one morning. They were selling of tons (literally) of junk they'd had donated to them over the last few years or so; stuff that wasn't easily sold in their actual stores. A lot of it was good stuff, too.

One thing that immediately caught my eye was a pallet (6' high, 4' wide X 4' wide) of nothing but boxed up hardcover books. I looked through some of the books in the top boxes and realized that there were some very old, and often valuable, books in this boxes. I decided I'd bid on it a bit and see where it goes.

The auctioneer kept bringing up lot after lot, but not the pallet of books. I was getting impatient by the time the morning wore on. Finally, when he'd pretty much sold everything that was in the yard back there that morning, he brought up the pallet of books. There was only a small crowd of folks left by then (about 20 or so). He described the contents of the pallet briefly by saying, "Here you go, folks... a bunch of books".

He looked around at the faces in the crowd and said, "I'm opening the bidding at one dollar." I about shit myself. I bid the $1 immediately to get things rolling. Well, after I bid, he looked around and said, "Once, twice, sold that man there for $1." I just laughed... and wondered how the Hell I was going to get this pallet home and what I was going to do with all those books.

When I asked the auctioneer afterwards why he'd let it go so cheaply, he said, "Did you see anyone trampling you to get in a bid?" I said no, I didn't. His reply, with a smirk on his face, was, "Gotta' know your audience in this job."

Well, needless to say, I got the books home and spent a few years going through them and selling some, giving some away, etc. However, that's not the point of this story. The point was finding things in books. So, with that in mind...

There were quite a few books in this collection that had the name of a fellow in them. His name was Charles Lounsbury. He was evidently a well-educated man; many of his books were text books from Cornell University. Anyway, whilst thumbing through one of them one day, a small business card fell out into my lap. It was a dentist's appointment card for Mr. Lounsbury. It also had his address and phone number on it.

Just for grins and giggles, I called the number on the card. An older-sounding man answered on the first ring. I said "Hello" and gave my name. I then asked the fellow if he was Charles Lounsbury. He said he was indeed. I told him about all the books I'd bought and how I had found this dentist appointment card in one of them. He was BLOWN AWAY immediately upon hearing about the books.

He told me that his sister had possession of his personal library at the time of her death, but he had not spoken with her in many years. When she died, it seems that someone cleaning out her house had donated all her possessions, including Charles' books, to the Salvation Army. Mr Lounsbury was very interested in possibly seeing his books again. He was wanting to leave some of them to his grandchildren upon his demise.

I made a date for him to drive from Sarasota, FL up to my home in Tampa and take whichever of his books he wanted back. The following Saturday he showed up. He was absolutely amazed to find all his books in the middle of my living room (huge stack of books, here's a sampling):

Anyway, he picked out 10 of 15 of his prized books and asked if he could take them. I, of course, said yes... for sure. After that we sat and had some coffee and he told me his life story. It was a wonderful afternoon! Charles and I became pretty good friends after that for about 10 or so years, until his death at age 88.

It's amazing, sometimes, the things you find in books. :)

*This posting previously published on my blog:

Nocturnal Slacker v2.0 | Letters to the void…

Bit of a weird question. Has anyone compiled a list of the requirements different websites have for passwords? It's for a thing.

Boosts appreciated!

What dullard called it 'remote exam invigilation' and not Proctors Without Borders?

R. A. Fisher and the science of hatred: newstatesman.com/international

If you've been wondering why noted academics of yesteryear like R. A. Fisher (a major figure in statistics; see en.wikipedia.org/wiki/Ronald_F) and David Starr Jordan (founding president of Stanford University; see en.wikipedia.org/wiki/David_St) have been having their names taken off things lately, the link looks like a good explainer of their views on eugenics, and why those views are now regarded as deeply racist, even for their times.

Our big writeup, "Cohomology fractals, Cannon-Thurston maps, and the geodesic flow", is now up on the arXiv at arxiv.org/abs/2010.05840. With David Bachman, Matthias Goerner, and Saul Schleimer. We describe the relationship between cohomology fractals and Cannon-Thurston maps, we give implementation details for our software, and we investigate the limiting behaviour of cohomology fractals, as the "visual radius" increases.

A collection of cohomology fractals for closed manifolds. The four manifolds (in reading order) are m280(1,4), s227(6,1), s400(1,3), and s861(3,1) from the SnapPy census. With David Bachman, Matthias Goerner, and Saul Schleimer.

Concerning "Mariam" Al-Asturlabiya (rayawolfsun.com/2015/02/06/the): A warning about how romanticizing past figures (in this case the only woman astrolabist known from the medieval Islamic world; see also en.wikipedia.org/wiki/Mariam_a) can result in creating biographical details for them out of thin air.

Interactive 3d knot table: prideout.net/knotgl/

One of many interesting visualizations on "the little grasshopper", prideout.net/, by Philip Rideout (author of the svg3d Python library that I linked earlier)

Going to start my Mastodon account with a result I put quite a bit of work into: Sorting 11 inputs using a sorting network requires 35 comparisons and sorting 12 inputs requires 39 comparisons. I still haven't finished writing the paper (and should be working on that instead), but all the code including a formal proof in Isabelle/HOL is on github: github.com/jix/sortnetopt

Kowhaiwhai are repeating decorative patterns used in New Zealand on Maori buildings. The National Library of NZ has a number of good examples at natlib.govt.nz/photos?text=kow and there's a brief guide to their interpretation at maori.org.nz/whakairo/default.

I can't find much analysis of their structure, though, beyond pointing to frieze groups for their symmetries. The part that interests me more is their fractal-like swooping structure, reminiscent of (and in some cases directly modeled on) fern fronds.

I have a user interface problem that I hope isn't only solved by adding yet another option for authors to understand.

Student types a mathematical expression. We allow implicit multiplication, so `xy` is interpreted as `x*y`.
What to do about `pi`? Is it `p*i` or `π`?

I guess most of the time, you'd expect it to be interpreted as π. But you might be doing something with complex numbers, and `p*i` is really what you meant.
I suppose rendering π would at least give you a hint to add the * symbol

I have made a version of Minesweeper where if you're forced to guess you'll always be safe — but if you guess when you didn't have to you'll always hit a mine.


mathstodon.xyz now has a live preview and completion of LaTeX!
This has been on my to-do list for a long time. You no longer need to worry if LaTeX will display properly or not.

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