Julian Perry Robinson (1941–2020)

Leader of the campaign against chemical weapons in the UK. A chemist, he spent the first half of his career doing forensic analysis on alleged chemical agents, including a Soviet "toxin" which proved to be bee shit instead. The second half was reports, briefings, committees, meetings. Most of his work is hard to evaluate, either because it was subsumed by committees, was sub rosa, or is just part of that great majority of good work which doesn't document itself and disappears from history. I can't find a full copy of his influential anonymous 1970 WHO report which helped birth the Biological Weapons Committee. He was apparently instrumental in the UK's strong 1996 law on chemical weapons. He was the UK arm, where Matthew Meselson was the US fist. "Of the two, Meselson is seen as the ‘lightning-speed thinker’ and Perry-Robinson‘the careful, studious one’ with exhaustive files. Yet their views often echo each other, and their collaboration has held firm for almost two decades." Together they maintained (and maintain) a complete database of all chemical weapon events since 1987. His father-in-law was the great economist Nicholas Kaldor, of Kaldor-Hicks improvement fame (far more common and important than Pareto improvements). He continued to work throughout his 70s, producing an influential timeline of chemical weapon use by Assad and an analysis of the notorious novichok family of nerve agents.

An unfinished proposal, which he started pushing in the 70s, is that natural-pandemic preparedness is the best way to counter biological weapons: to make them ineffective, and so to remove all incentive to use them, and so to remove all incentive to make them.

Arianna Rosenbluth (1927–2020)

Physicist and computer scientist. During her work at Los Alamos on the H bomb, she wrote the first full implementation of a Markov chain Monte Carlo method, one of the most important algorithms of all time and the key to the recent ascendence of Bayesian statistics. During her PhD, which she got aged 21, Thomas Kuhn was a labmate. She was a world-class fencer, winning the Texas women's championship and a municipal men's championship. She qualified for the 1944 Olympics, which were cancelled owing to a war, and for the 1948s, which she didn't attend because no one would pay for her travel. Her favourite charity was the American Society for the...

Obituary