Ancient Stalagmite Circle and Neanderthal Impression

A secret society of French mathematicians has been revolutionising the field of mathematics under a pseudonym for nearly a century. Columnist Jacob Aron finds that this mythic collective provided maths a rigorous and useful foundation, and did some real harm along the way

An impression made in clay around 175,000 years ago could be a kneeprint left by one of the builders of a strange stalagmite circle found deep inside Bruniquel cave in south-west France