James Lovelock died last week on his 103rd birthday. He was a Fellow of the Royal Society of London (FRS) mainly for his brilliant work on technology for analysing gases. His small device was the ‘breakthrough’ for spotting freons. It was a thousand times more powerful than anything else available in the 1950s. He travelled to Antarctica and was able to detect chlorofluorocarbon gases there. They were causing a hole to form in the protective ozone layer in the south. Lovelock is also famous for his Gaia Hypothesis – that the Earth tends to balance its systems, almost like the homeostasis of the human body, keeping temperatures and other variables within limits favourable for life. His idea, and the very name, taken from Greek mythology with holistic connotations outraged orthodoxies, despite evidence supporting it. Our Science Show today features these debates and the man himself.