Percy Williams Bridgman was a pioneering American physicist whose groundbreaking work in high-pressure physics established him as a leading figure in twentieth-century physical science. Born in Cambridge, Massachusetts on April 21, 1882, he received his entire formal education at Harvard University, earning his A.B. in 1904, A.M. in 1905, and Ph.D. in Physics in 1908. He joined the Harvard faculty in 1910 and rose steadily through academic ranks, becoming a full professor in 1919, Hollis Professor of Mathematics and Natural Philosophy in 1926, and Higgins University Professor in 1950. His academic career spanned over five decades until his death on August 20, 1961 in Randolph, New Hampshire, marking him as one of Harvard's most distinguished and enduring faculty members.
Bridgman's most significant contribution was his development of apparatus capable of producing extremely high pressures up to 100,000 atmospheres, for which he was awarded the Nobel Prize in Physics in 1946. He conducted extensive investigations on the properties of matter under high pressure, studying compressibility, electrical and thermal conductivity, tensile strength, and viscosity across more than 100 different compounds. His innovative sealing methods solved critical leakage problems in high-pressure vessels, enabling sustained experimentation at previously unattainable pressure levels. Among his notable discoveries were high-pressure forms of ice and phase changes in solids, which provided crucial insights into material behavior under extreme conditions. His development of the Bridgman-Stockbarger technique for crystal growth further expanded the applications of his high-pressure research across multiple scientific disciplines.
Bridgman's influence extended far beyond his experimental work, as he made significant contributions to the philosophy of physics through his operational approach to scientific concepts. His seminal book The Logic of Modern Physics (1927) introduced operationalism and coined the term operational definition, profoundly influencing how physicists conceptualize and measure physical phenomena. He was also one of the 11 signatories to the Russell-Einstein Manifesto, demonstrating his engagement with broader societal issues. His high-pressure techniques laid the foundation for later achievements including the synthesis of diamonds and advances in geophysics for understanding Earth's interior. Bridgman's rigorous methodology and philosophical insights continue to shape experimental physics and scientific thinking, cementing his legacy as both an ingenious experimentalist and a profound scientific thinker.
