Percy Williams Bridgman

Percy Williams Bridgman (21 April 1882 – 20 August 1961) was an American physicist who won the 1946 Nobel Prize in Physics for his work on the physics of high pressures. He also wrote extensively on the scientific method and on other aspects of the philosophy of science.

Biography
Bridgman entered Harvard University in 1900, and studied physics through to his Ph.D.. From 1910 until his retirement, he taught at Harvard, becoming a professor in 1919. In 1905, he began investigating the properties of matter under high pressure. A machinery malfunction led him to modify his pressure apparatus; the result was a new device enabling him to create pressures eventually exceeding 100,000 kgf/cm² (10 GPa). This was a huge improvement over previous machinery, which could achieve pressures of only 3,000 kgf/cm² (0.3 GPa). This new apparatus led to an abundance of new findings, including on the effect of pressure on electrical resistance, and on the liquid and solid states. Bridgman is also known for his studies of electrical conduction in metals and properties of crystals. He developed the Bridgman seal and is the eponym for Bridgman's thermodynamic equations.

Bridgman made many improvements to his high pressure apparatus over the years, and unsuccessfully attempted the synthesis of diamond many times.

His writings on the philosophy of science advocated operationalism, and he coined the term operational definition. He was also one of the 11 signatories to the Russell-Einstein Manifesto.

Death
Bridgman committed suicide by gunshot after living with metastatic cancer for some time. His suicide note read in part, "It isn't decent for society to make a man do this thing himself. Probably this is the last day I will be able to do it myself." Bridgman's words have been quoted by many on both sides of the assisted suicide debate.

Honors and awards
Bridgman received Doctors, honoris causa from Stevens Institute (1934), Harvard (1939), Brooklyn Polytechnic (1941), Princeton (1950), Paris (1950), and Yale (1951). He received the Bingham Medal (1951) from the Society of Rheology, the Rumford Medal from the American Academy of Arts and Sciences, the Cresson Medal from the Franklin Institute, the Roozeboom Medal from the Royal Academy of Sciences of the Netherlands, and the Comstock Prize of the National Academy of Sciences. He was a member of the American Physical Society and was its President in 1942. He was also a member of the American Association for the Advancement of Science, the American Academy of Arts and Sciences, the American Philosophical Society, and the National Academy of Sciences. He was a Foreign Member of the Royal Society and Honorary Fellow of the Physical Society of London.

The Percy W. Bridgman House, in Massachusetts, is a U.S. National Historic Landmark designated in 1975.