Francis Aston
DOI: 10.1063/PT.5.031041
It’s the birthday of Francis Aston, who was born in 1877 in Birmingham, England. After studying physics at the University of Birmingham, Aston was recruited by J J Thomson to join Cambridge University’s Cavendish lab. There, he investigated the chemical and physical properties of nuclei with his invention, the mass spectrometer (shown in the photo). It was Aston who discovered that an element’s isotopes differ from one another by whole numbers. He also measured the mass of the helium-4 nucleus and determined that it’s lower than the combined mass of its constituents. Aston’s discovery led to the realization that nuclear fusion could be a potent source of energy.
Date in History: 1 September 1877
