# A year ago – a mathematical giant fell to COVID-19

John Horton Conway died of COVID-19 on April 11, 2020.

This is two and a half weeks late. I have been looking for something profound to say. I will not find it.

I met Conway in the fall of 2013. I was on sabbatical, trying to take interesting math classes at Queens College. I was happy I found a class in Combinatorics. Logic made sense for me (it turned out to be both challenging and rewarding.) And I needed one more. Someone, probably Kirsten, let me know: “There’s still seats in Number Theory – you have to take Conway” – and I did.

Conway had retired, but I think Kent Boklan brought him out of retirement to teach at Queens College. They were part of the same mathematical genealogy, going back to Davenport and Littlewood. That was good fortune for me, for all of us. Conway’s stroke interfered with his mobility, not his mind, and he clearly enjoyed engaging with students.

Conway was the most famous living mathematician. Maybe. Probably. The Number Theory was fun. But the stories were wonderful. He knew. personally, the guys (almost all men) that we read about. He told us about their work. He did not hide who he liked, who he disliked, who he felt was a genius, and who he felt was not. He talked about people skills (and lack thereof) and questionable politics. I was an idiot for taking notes on quadratic reciprocity, but not on who insulted whom at a cocktail party during a conference in which city.

Conway may well have been the most famous living mathematician. But he was certainly keeping an eye on – it seemed – all the others.

He liked attention, but most students ran off after class. At some point I learned to follow him. In that way I got personal lessons in Doomsday and other stuff. But I remember Doomsday. His lessons sounded a lot like these, except they were in an office, not a bar. And they were a few months before the YouTubes were recorded.

When he died I told my students. I shared the Game of Life. I shared the Randall Munroe tribute. I told a senior with mathematical promise about the Conway knot and its recent solution (turned out, she already knew).

This year I encouraged a student to do a brief project on the Game of Life. And instead of my regular elective, I decided to teach an Intro to Number Theory. I taught my students to appreciate mathematical genealogy, and to recognize some royal lineages, including Conway’s. When we looked at Fermat’s Last Theorem, I gave them a video about Andrew Wiles, wherein Conway was one of the talking heads.

And just now, needing a nice application of congruences, we turned to Doomsday, as Conway conceived of it, as Conway himself described it. My students watched the videos that are posted just above. And I shared with them how John showed off his speed, which was well known. When I was in the office he also showed off his intricate knowledge of the dates of adoption of the Gregorian Calendar, which is a bit more than one might think, since in the place of today’s Germany were maybe 50 or 100 individual states – some of which adopted, switched back, and adopted again.

I wish I could have found something profound to say here. But in the almost three weeks I have been stalling, I have shared with my students bits of the playfulness with which John Horton Conway approached mathematics. Maybe that’s a better tribute than the words I could not find.