My final class (probably)

Class photo

Last Thursday I wrapped up Math 583, Introduction (interpreted in a rather generous sense) to K-Theory, which is likely to be the last class I teach at Penn State.  My students presented me with a beautiful and generous card, and also insisted on taking a group photo (see picture).  I was instructed to put a picture of "something K-theoretic" on the board above us, so I chose the irrational slope foliation on the 2-torus, which Michael Atiyah had me read about when I arrived at Oxford as a new graduate student, and which I was teaching my own students about a couple of weeks back.

It has taken me a lot longer than you might expect to realize that my life as a professional mathematician revolves around my delight in teaching - not simply in teaching classes in the usual sense, but in explaining, making stuff clear, a gift that my parents gave me (both of them being teachers, and my father a teacher of mathematics who ignited my delight in geometry from a very early age). Most of my research has arisen from a desire to explain things to myself which I believed, sometimes wrongly, were clear to everyone else.  I don't think that this is everyone's path, or that it has to be, but it was certainly mine.   Writing books is of course a well-known symptom (compare Ecclesiastes 12:12) and I have churned out a few.  We are meeting on Monday with the publisher from Springer for Mathematics for Sustainability, which as regular readers know has been a major dream of mine for many years. It is incredibly exciting to feel that finally coming together.

Of course the temptation for people with this sort of gift is to believe that being able to explain things is enough.  (That might account for my thinking seriously at one point in my youth about becoming a pastor - after all, it's all about explaining the Bible, innit?  Mercifully I was dissuaded from this.)  Explaining is often a necessary step, but for accomplishing meaningful change, it is never a sufficient one.  We also need builders of community, summoners to action, companions in suffering, co-celebrants in joy: and that is true whether I'm talking about the community of faith or about working for a sustainable future.  For those who have been that sort of partners to me and my family, especially in the crucible of the last few years, I am truly grateful.

Onward!