Today is the birthday of Eugene Demarcay, born in 1852, he became an expert on spectra after an explosion destroyed his eye, in1898 he helped Madame Curie show the presence of radium in a sample she isolated the new element from. In 1896 he began research that led to the discovery of europium.
Today is also the birthday of Lev Landau, born in 1935 he pioneered the idea of magnetic domains, worked on magnetism and low temperature research on isotopes. A serious car accident ended his career. He died in 1968 at age 60.