Today's chemistry tie celebrates the birthday of Linus Pauling (1901-1994), often regarded as "the Father of the Chemical Bond." In the 1920s and 1930s his research led to understandings of molecular bonding that continue to the present. For his scientific work, Pauling was awarded the Nobel Prize in Chemistry in 1954. In 1962, for his peace activism, he was awarded the Nobel Peace Prize. This makes him the only person to be awarded two unshared Nobel Prizes.