Strange quark
The first strange particle (a particle containing a strange quark) was discovered in 1947 (kaons), but the existence of the strange quark itself (and that of the up and down quarks) was only postulated in 1964 by Murray Gell-Mann and George Zweig to explain the Eightfold Way classification scheme of hadrons. The first evidence for the existence of quarks came in 1968, in deep inelastic scattering experiments at the Stanford Linear Accelerator Center. These experiments confirmed the existence of up and down quarks, and by extension, strange quarks, as they were required to explain the Eightfold Way.
Paris in the Belle Époque
The physicist Henri Becquerel (1852-1908), while studying the fluorescence of uranium salts, discovered radioactivity in 1896, and in 1903 was awarded the Nobel Prize in physics for his discovery. Pierre Curie (1859-1906) and Marie Curie (1867-1934) jointly carried on Becquerel's work, discovering radium and polonium (1898). They jointly received the Nobel Prize for physics in 1903. Marie Curie became the first female professor at the University of Paris and won the Nobel Prize for chemistry in 1911. She was the first woman to be buried in the Panthéon.