Patriotism, at least in its usual sense of love of one’s country over others, veneration of the virtue of its people over others, and adoration of its flag, is awful, irrational nonsense.

## Limitless as that space too narrow for its inspirations

In which I recall, via neurologist Oliver Sacks, some musings of Sylvester from 1877 on the limitlessness of mathematics.

## The Doors of Crime Perception

Crime is uniquely susceptible to the manipulation of perceptions.

## The beauty of mathematics shows itself to patient followers

In September 2018 I gave a talk on the life and mathematics of Maryam Mirzakhani in the School of Physical and Mathematical Sciences colloquium at NTU in Singapore.

## Talk on Counting Curves on Surfaces, September 2018

On 19 September 2018 I gave a talk at the National University of Singapore (NUS) in the Topology and Geometry seminar. The talk was entitled “Counting Curves on Surfaces”.

## The algebra and geometry of contact categories, Melbourne July 2018

On Monday July 23 2018 I gave a talk in the Geometry and Topology seminar at the University of Melbourne.

## The Brain makes Contact with Contact Geometry

It’s always nice, intellectually, when two apparently unrelated areas collide. I had an experience of this sort recently with an area of mathematics — one very familiar to me — and an ostensibly completely distinct area of science. On the

## “The beauty of mathematics shows itself to patient followers” — The work of Maryam Mirzakhani

The recent passing of Maryam Mirzakhani came as a shock to many of us in the world of mathematics. Together with Norman Do, we attempt to share something about Mirzakhani’s work.

## The disempowerment of positive thinking

I’m quite skeptical of the “positive psychology” movement, as it encourages the individualisation of some problems that are really social.

## A-infinity algebras, strand algebras, and contact categories

In previous work we showed that the contact category algebra of a quadrangulated surface is isomorphic to the homology of a strand algebra from bordered Floer theory. Being isomorphic to the homology of a differential graded algebra, this contact category algebra has an A-infinity structure. In this paper we investigate such A-infinity structures in detail. We give explicit constructions of such A-infinity structures, and establish some of their properties, including conditions for the nonvanishing of A-infinity operations. Along the way we develop several related notions, including a detailed consideration of tensor products of strand diagrams.