My ‘no-fly’ moment came when I decided that I should be living according to the scientific arguments that I accept to be valid.

What I don’t miss: duty free nihilism, passing all my hard disks and laptop through security, the smell of airplane interiors, all that plastic for a small tasteless snack and bad coffee, days that started before dawn and ended after midnight so that I could get there and back in a day.

What’s hard: my elderly parents and sister live in Australia.

What’s surprisingly easy: work meetings via multiparty teleconferences (e.g. Zoom/StarLeaf/Hangouts), telling colleagues “I’m sorry but I don’t fly anymore”, more time with my family and in my garden, getting there on-time by train (SNCF has never let me down, touch wood).

What drives me crazy: scientists who argue that we shouldn’t be trying to change our institutional practices because ‘nothing should stop excellent science’, astrophysicists who think that there are urgent cosmological problems, holiday junkets thinly veiled as science conferences.