Future Nobel laureate Wolfgang Pauli was a little over six-and-a-half years old when this photo was taken in December 1906. His biographer Charles Enz notes that that young Wolfi contracted all the usual childhood diseases and, to use the typically Viennese expression, es war ihm immer fad – he always felt bored.

By the age of four he was already adept in the art of contradicting his elders that would later help him to reshape modern physics. On being told during one of his walks through Vienna, ‘Now we are walking over the Danube Canal', he replied firmly, ‘No, Aunt Erna, this is the Wien Canal, which flows into the Danube Canal.’