R. A. Fisher and the science of hatred: https://www.newstatesman.com/international/science-tech/2020/07/ra-fisher-and-science-hatred

If you've been wondering why noted academics of yesteryear like R. A. Fisher (a major figure in statistics; see https://en.wikipedia.org/wiki/Ronald_Fisher) and David Starr Jordan (founding president of Stanford University; see https://en.wikipedia.org/wiki/David_Starr_Jordan) 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 https://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.

Attenborough: Saying Boo to a Sloth!

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

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

One of many interesting visualizations on "the little grasshopper", https://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: https://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 https://natlib.govt.nz/photos?text=kowhaiwhai and there's a brief guide to their interpretation at http://www.maori.org.nz/whakairo/default.php?pid=sp55&parent=52

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.

https://cornelllabofornithology.github.io/auk/

I found this helpful for putting math on my Jekyll site:

I grew up in Alabama in the US, am Eastern Orthodox, and study computational 3-manifold topology.

Joined Jun 2020