Today is World Blood Donor Day. It’s celebrated every year on the birthday of Karl Landsteiner, the Austrian biologist and physician who developed the modern system of blood group classification in 1901. He was awarded a Nobel Prize in 1930 and died 13 years later, aged 75, while still working in his laboratory.

A related fact: in Japan, it’s widely believed that your blood type influences your personality, in the same way that people assign character traits to different star signs here.