Percy Bridgeman high-pressure materials research

Harvard physicist, Nobel laureate, tetrahedral anvil press at gigapascal pressures, foundation for synthetic diamond manufacture. Used to anchor the "parameter" usage dispute with Hallock Campbell.

You have to understand the psychology of this. The guy who wrote most of the AWS definitions was Hallock Campbell, who's passed away now. Hallock was a Harvard grad, and he was a real stickler for words. Back in 1985, I was on sabbatical in Japan, and I had written a paper in the Welding Journal where I used the word "parameter" in the title. I get this letter in Japan from Hallock telling me I'd used the word "parameter" incorrectly. I read his thing, and I went to the office I was in, which had an unabridged Merriam-Webster dictionary about this thick. I looked up "parameter," and there it had four or five meanings, and it gave examples, including one from Percy Bridgman. Anybody know who Percy Bridgman was? A professor at Harvard who won the Nobel Prize. He used the tetrahedral anvil press to develop huge pressures for geological studies of minerals and phase transformations. He won the Nobel Prize for his studies at ultra-high pressure — gigapascals, millions of PSI. That's how people make artificial diamonds now, using Bridgman's tetrahedral anvil press. Bridgman was a professor at Harvard in the '30s and maybe into the '40s, and Hallock Campbell probably was one of his students. I wrote back to Hallock with a copy of the definition from the book, and said, this is how I used it and this is how P.W. Bridgman used it. He handwrote on the back and sent it back: "Percy, how could you?"

Extended sketch — Harvard physics professor, Nobel laureate, suicide in Randolph NH 1961. Invented the tetrahedral anvil press, opened up high-pressure materials science (artificial diamond synthesis). Used as the lead-in to the central teaching point: hydrostatic stress suppresses brittle fracture, and at sufficient pressure even steel necks like plasticine. Tom anchors the rock-creep / deep-mine point in Bridgman's framework.

Now, anybody know who Percy Bridgman was? Everybody heard of P.W. Bridgman? Well, this is Percy. He won the Nobel Prize. He was a professor at a school just north of us here — little school called Harvard. He was born 1882 in Cambridge, Massachusetts. He died in 1961 in Randolph, New Hampshire. He committed suicide, by the way. His field was physics and he won the Nobel Prize.