Born on 28 February 1901 in Portland, Oregon, Linus Pauling was a physical chemist who won an unprecedented two unshared Nobel Prizes. He received a bachelor’s degree from Oregon Agricultural College (now Oregon State University) and a PhD in chemistry and mathematical physics from Caltech. Pauling set himself up for success by learning x-ray and electron diffraction to determine molecular structure and by studying quantum mechanics in Europe. Throughout the 1930s Pauling made major advances in understanding the bonding of molecules; he introduced the concepts of bond-orbital hybridization and bond resonance and came up with a scale for electronegativity. His 1939 book The Nature of the Chemical Bond, and the Structure of Molecules and Crystals encapsulates his early work. Pauling also took an interest in biology, as he analyzed the magnetic properties of hemoglobin and studied the structure of proteins. In 1949 Pauling and colleagues identified the structural defect in hemoglobin that caused sickle-cell anemia. Pauling was awarded the 1954 Nobel Prize in Chemistry “for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances.”
In the post-World War II period, Pauling became more known for his activism than his science. He and his wife, Ava Helen Pauling, advocated strongly for banning atmospheric testing of nuclear weapons, and they circulated a petition that garnered thousands of signatures. For his efforts Pauling was awarded the Nobel Peace Prize on 10 October 1963, the day the Limited Nuclear Test Ban Treaty went into effect. He also became known for his promotion of vitamins, particularly vitamin C, for their health benefits. Pauling died of prostate cancer in 1994. (Photo credit: AIP Emilio Segrè Visual Archives, W. F. Meggers Gallery of Nobel Laureates)
