The BCS Theory was published one year before Cooper came to Brown, where he was ultimately appointed Henry Ledyard Goddard University Professor in 1966 and Thomas J. Watson Sr. Professor of Science in 1974. At Brown, Cooper continued to research and publish studies about superconductivity, but soon felt drawn to investigate new questions. He turned his attention to another difficult problem: understanding how learning and memory take place in the brain.

With the help of several colleagues, Cooper began investigating ways to model the mechanisms of the brain’s visual cortex. The model was based on the idea that synapses, which carry chemical signals between neurons, were crucial in memory. Along with Brown Ph.D. students Paul Munro and Elie Bienenstock, Cooper published a theory in 1982 that was one of the first mathematical models showing how synaptic modification could lead to some forms of learning and memory. The theory was named BCM Theory after Bienenstock, Cooper and Munro.

The BCM Theory and Cooper’s other endeavors in brain research helped lay some of the groundwork for many of Brown’s programs in neuroscience. For example, the University's Center for Neural Science, which was established in 1973 with Cooper as founding director, helped build an early foundation for what is now the Carney Institute for Brain Science.

Peter Bilderback, who worked closely with Cooper for more than 20 years in Brown’s Department of Physics, said an inexhaustible sense of curiosity was one of Cooper’s hallmarks.

“Leon's intellectual curiosity knew no boundaries,” Bilderback said. “He was comfortable conversing on any subject, including art, which he loved greatly. Where others might see art and science as diametrically opposed, Leon saw deep commonalities between the two. He recognized both as inherently creative enterprises. He often compared the construction of physics to the building of a great cathedral, both beautiful human achievements accomplished by many hands over many years and perhaps never to be fully finished.”

Throughout his career, Cooper was regarded as a dedicated educator with a passion for teaching and mentoring students. Valles, whose office at Brown was located two doors down from Cooper’s, said that he never got over feeling starstruck by his Nobel-winning colleague, and remembers him as an educator who found creative ways to inspire students and was ceaselessly open to new ideas. 

Cooper taught an introductory physics course, and for many years, Valles recalled, he structured the class around the award-winning stage play “Copenhagen” by Michael Frayn, which centers around the 1941 visit of German nuclear physicist Werner Heisenberg to his former colleague, Niels Bohr. The class was team-taught with two other Brown professors: Cooper explained the physics, historian Abbott Gleason put the information in context, and Oskar Eustis, a professor of theatre, speech and dance, advised on the reading of the play. 

“Leon was just this beautiful, intellectual, positive force,” Valles said.

Bienenstock, the BCM Theory collaborator and Brown Ph.D. graduate, first met Cooper in 1977 at the Collège de France in Paris, where Cooper was an invited lecturer. He said the esteemed scientist’s interests not only crossed academic borders, but also international borders.

“Beyond his varied scientific interests, he was passionate about art and culture,” said Bienenstock, now an associate professor of applied mathematics and of neuroscience at Brown. “He spoke French well and was well-read in both English and French. He positively loved French culture and French life.”

Bienenstock noted that Cooper worked intentionally to support all of his graduate students, who came from diverse countries and “sometimes had a bit of a hard time getting used to life on an American campus.”

Cooper’s retirement from teaching — but not from conducting research — at Brown in 2014 inspired stacks of letters from former students, including one from Stephen Fried, a member of the Class of 1964.

“I took Leon Cooper’s brilliant course on quantum mechanics, a subject that had always fascinated me,” Fried wrote in a letter to the Brown Alumni Magazine. “I aced both semesters and then went to work on atomic and laser physics. Cooper taught the course right out of Dirac! Every day he would enter the room and write the Schrödinger equation on the upper left-hand side of the blackboard, and we would then analyze the Hamiltonian for a particular system… One of the projects I worked on, the basic research in HF vibrational energy transfer, eventually made the Star Wars laser possible, something that helped end the Cold War. Thanks for the vote of confidence, Professor Cooper. Your course was an example of how physics ought to be taught!”

Along with the Nobel, Cooper won a number of awards and recognitions for his work, including the Comstock Prize from the National Academy of Sciences and the Descartes Medal from the Academie de Paris. He was named a fellow or member of many prestigious organizations, including the John Simon Guggenheim Memorial Foundation, the National Academy of Sciences, and the American Academy of Arts and Sciences. 

The New York Times noted that it has frequently been reported that the character Sheldon Cooper, a math and science genius and protagonist in the television sitcom “The Big Bang Theory,” is named in part after Cooper.

Despite all the accolades, Cooper remained a steadfast learner throughout his career at Brown and always took on new challenges.

“That’s one of the things that has always made me very happy at Brown,” Cooper said in a 2013 interview. “I can do what I want to, and for me that’s everything… People ask me: What did you do after your Nobel Prize? Did you go to work every day trying to win another one? Absolutely not. You just go to work.”

Cooper is survived by his wife, Kay; his daughters from his first marriage, Coralie and Kathleen; and four grandchildren, according to the New York Times.