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.


The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!