The Majorana mystery

Strangely, another of Fermi’s assistants also disappeared. Italian physicist Ettore Majorana contributed to particle physics the proposition that spin-½ particles could be their own anti-particles, but the end of his life remains shrouded in mystery.

Whilst studying at university, Majorana had shown up at Fermi’s lab and asked if he could switch his focus from engineering to physics. Fermi explained his current research and allowed Majorana to briefly look over some data. Majorana spent the night recalculating Fermi’s results and returned the next day to explain to the surprised Fermi that his results were indeed correct. After being accepted into Fermi’s institute, Majorana would scribble calculations on cigarette packets on his way to work on the tram but throw the packet away when he had finished smoking. Fermi later commented: “There are several categories of scientists in the world; those of second or third rank do their best but never get very far. Then there is the first rank, those who make important discoveries, fundamental to scientific progress. But then there are the geniuses, like Galilei and Newton. Majorana was one of these.”

In 1932, Irène Joliot-Curie and Frédéric Joliot-Curie observed that beryllium atoms that had been bombarded with alpha particles emitted a kind of radiation that led to the emission of protons from a wax target. They assumed that they had observed gamma radiation, but their calculations seemed to imply a violation of conservation of energy. Hearing of the result, Majorana rudely commented: “Oh, look at the idiots; they have discovered the neutral proton, and they don’t even recognise it.”

Always a shy man, he became increasingly withdrawn over time and stopped cutting his hair. In 1938, he disappeared, most probably on or after taking the Naples-Palermo ferry, and his fate remains a mystery.