Sir Joseph John Thomson, British physicist, 1900.
© Science Museum / Science & Society Picture Library
Sir Joseph J Thomson (1856-1940) studied sciences at Trinity College, Cambridge. After graduating, he continued to work at Cambridge University and in 1896 began experiments on cathode rays, demonstrating that they were in fact particles with a negative charge and were much smaller than an atom. These particles were later renamed electrons. In 1906, he was awarded the Nobel Prize for Physics.