Linus Pauling (1901 - 1994) was an American chemist, biochemist, and peace activist widely regarded as one of the most influential scientists of the 20th century. He pioneered the application of quantum mechanics to chemistry, transforming the understanding of the chemical bond and molecular structure, and later became a prominent campaigner against nuclear weapons testing. Pauling remains the only person to have won two unshared Nobel Prizes: the Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize for 1962. [1]
Early life and education
Linus Carl Pauling was born on February 28, 1901, in Portland, Oregon. He studied chemical engineering at Oregon Agricultural College (now Oregon State University) before undertaking graduate work at the California Institute of Technology, where he earned his PhD in 1925. [4] A Guggenheim Fellowship then allowed him to study in Europe, where he encountered the emerging field of quantum mechanics that would shape his career.
The nature of the chemical bond
Returning to Caltech, Pauling applied quantum theory to explain how atoms combine to form molecules. His work on orbital hybridization, electronegativity, and resonance provided a unified framework for understanding molecular structure. These ideas were synthesized in his landmark 1939 book The Nature of the Chemical Bond, among the most cited scientific texts of the century, and led to his receiving the 1954 Nobel Prize in Chemistry. [2]
Molecular biology and medicine
Pauling extended his methods to biological molecules, using X-ray crystallography and model building to study the structure of proteins. In the early 1950s he proposed the alpha helix as a fundamental structural element of proteins. In 1949 he and his colleagues described sickle-cell anemia as a "molecular disease" caused by an abnormal form of hemoglobin, helping to establish the field of molecular medicine. [4]
Peace activism
After the Second World War, Pauling became an outspoken opponent of nuclear weapons and atmospheric testing, warning of the genetic and health risks of radioactive fallout. A petition against nuclear testing that he organized was signed by thousands of scientists and helped build support for the 1963 Partial Nuclear Test Ban Treaty. For these efforts he was awarded the Nobel Peace Prize for 1962. [3]
Later years and legacy
In his later career Pauling advocated orthomolecular medicine and the therapeutic use of large doses of vitamin C, claims that drew significant criticism from much of the medical community. He founded the research center now known as the Linus Pauling Institute and continued his work until his death on August 19, 1994, in Big Sur, California. Recognized with the National Medal of Science and many other honors, he is remembered as a founder of quantum chemistry and molecular biology and as a leading voice for nuclear disarmament.
