Cécile DeWitt-Morette, mathematical physicist who made foundational contributions to the study of Feynman functional integrals, organized the first American conference on general relativity, and founded the Les Houches Summer School, was born #OTD in 1922.
Images: UT-Austin

Cécile Morette grew up in Normandy, studying math and physics at the University of Caen. Her graduate work, on quantum mechanics, took place at the University of Paris. Much of her education took place during the German occupation of WWII.

While in Paris, she worked with Irène and Frédéric Joliot-Curie. After finishing her doctorate in 1947, she moved to Copenhagen to work with Neils Bohr. Her next stop was the Institute for Advanced Study, where she worked with Robert Oppenheimer.

It was at the IAS that Cécile met Bryce DeWitt, who proposed to her in 1951. She liked him pretty well, but turned him down because he wasn’t French.

She eventually reconsidered. The war had taken a great toll on French science. Cécile decided that she would accept Bryce's proposal, on the condition that he help her found a school for theoretical physics in France.

The Les Houches Summer School was established in April of 1951, and Cécile and Bryce were married later that month. https://www.houches-school-physics.com 

In 1956, Bryce and Cécile moved to North Carolina, where they co-founded UNC's Institute of Field Physics. They organized the first US conference on general relativity, which was held there in 1957.

Cécile invited Richard Feynman to the conference, where he gave a famous talk on gravitational waves. His “sticky bead” argument convinced the other participants that gravitational waves carried energy, and therefore could be detected. His remarks:
http://www.edition-open-sources.org/sources/5/34/index.html

Cécile's conference, as much as any other event, set physicists on the path that would eventually lead to @LIGO and the detection of gravitational waves in 2015.

The conference report is online and open access:
http://www.edition-open-sources.org/sources/5/index.html

Cécile and Bryce were both appointed “research professor” when they arrived at UNC. After a few years, Bryce was promoted to full professor. But Cécille, who had brought in the same grants and made comparable contributions, was demoted to lecturer.

The University claimed that the demotion was because of nepotism rules, but when pressed they were unable to point to any actual regulations. Cécile and Bryce noped right out of there and headed for Texas.

UT-Austin had its own nepotism rules, which they circumvented by making Cécile a professor in Astronomy instead of Physics. About ten years later, in 1983, they ditched the rules and made Cécile a professor in the Physics department.

While at UT, Cécile worked on methods of functional integration underlying Feynman's path integral approach to quantum mechanics, and a host of other topics.

It was there that Cécile wrote her book "Analysis, Manifolds, and Physics" with Yvonne Choquet-Brouhat and Margaret Dillard-Bleick. The first edition came out in 1977, followed by a revised version in 1982. You'll find a copy on the shelves of most mathematical physicists.

Cécile worked on whatever she found interesting, and she was famous for having a seemingly inexhaustible supply of thesis-level problems for curious students.

She had a "problem drawer" in one of her file cabinets — it may very well have been one of the drawers visible in the picture in the first tweet. When Cécile met with a new student, she'd pull something from the drawer for them to work on.

Many of my grad school friends (my PhD is from UT-Austin) worked with Cécile and wrote papers on problems pulled from her drawer:
https://arxiv.org/abs/math-ph/0012006

Cécile DeWitt-Morette, a towering figure of mathematical physics, was generous, approachable, and brilliant. She passed away in 2017 at the age of 94.

Of all Cécile’s contributions, the Les Houches schools may be the most enduring. Generations of physicists have learned about cutting-edge research there; the list of attendees and lecturers is a who’s-who of prominent physicists and mathematicians. https://www.houches-school-physics.com/the-school/nobel-prizes-and-fields-medalists/

UT-Austin put together this extensive online memorial about her life and scientific contributions:
https://web2.ph.utexas.edu/utphysicshistory/CecileDeWittMorette.html