John Horton Conway. 26 December 1937—11 April 2020

John Conway was without doubt one of the most celebrated British mathematicians of the last half century. He first gained international recognition in 1968 when he constructed the automorphism group of the then recently-discovered Leech lattice, and in so doing discovered three new sporadic simple groups. At around the same time he invented The Game of Life, which brought him to the attention of a much wider audience and led to a cult following of Lifers. He also combined the methods of Cantor and Dedekind for extending number systems to construct what Donald Knuth (ForMemRS 2003) called ‘surreal numbers’, the achievement of which Conway was probably most proud. Throughout his life he continued to make significant contributions to many branches of mathematics, including number theory, logic, algebra, combinatorics and geometry, and in his later years he teamed up with Simon Kochen to produce the Free Will theorem, which asserts that if humans have free will then, in a certain sense, so do elementary particles. In this biographical memoir I attempt to give some idea of the depth and breadth of Conway's contribution to mathematics.

A Bracing Nonlinear Walk in Applied Mechanics: Memoirs and Reflections

This article is an informal auto-biographical memoir by Mike Thompson, reflecting in retirement on his scientific researches in nonlinear phenomena, wandering pictorially from shell buckling, through bifurcations and chaos to climate tipping points. Some ideas and advice to young researchers are offered whenever it seems appropriate. Two research groups at University College London, and their two IUTAM Symposia are given some prominence, as are the ten years editing the Philosophical Transactions of the Royal Society.

Lawrence Ernest Lyons 1922–2010

Lawrie Lyons was a person of vision with a will to initiate and follow-through. This characteristic was evident in his scientific agenda, in his academic and Christian actions and in the care that he had for his family. These strands are inextricably woven in the texture of his life, some of which I have known since I met him as tutor before entering Sydney University in 1954—but afterwards as his research student and as a friend and collaborator. It is from these perspectives that I write this biographical memoir.