The Intersection of Physics and Philosophy

“So originally, there was this idea of, oh, well, maybe the physical world behaves strangely; that things that are distant from each other can still have kind of a special connection.” – Gregg Jaeger

CGS Associate Professor Gregg Jaeger has a unique connection to the 2022 Nobel Prize winners in physics. Photo by Chelsea Feinstein

This idea, which has its roots in work done at Boston University, was recognized on an international scale last year when the 2022 Nobel Prize for Physics was awarded to Alain Aspect, John Clauser, and Anton Zeilinger for their revolutionary research in quantum physics.

Their experiments showed that even after separating, two particles will remain connected in a surprising way, paving a new path for quantum technology.

For College of General Studies Associate Professor Gregg Jaeger, the recognition of the trio’s work held a special meaning, for both himself and Boston University.

“There’s something special about BU’s relationship to this Nobel Prize,” Jaeger said. “The book I edited [in 2021], one of the contributors is John Clauser.”

Jaeger’s book, titled Quantum Arrangements, was also co-edited by Nobel recipient Anton Zeilinger and Alexander Sergienko, professor of Electrical and Computer Engineering at BU’s College of Engineering. Clauser cited the chapter he contributed to Jaeger’s book during his official Nobel recipient lecture in Stockholm.

The book showcases another connection between BU and the Nobel Prize recipients, according to Jaeger.

“The book was in honor of Michael Horne, a BU Physics PhD graduate with whom I published and who collaborated with both Clauser and Zeilinger on the papers for which they got the prize,” Jaeger said.

Jaeger said he and Horne, who died in 2019, shared the same PhD advisor, Abner Shimony, the late professor of Philosophy and Physics Emeritus at Boston University.

Shimony’s work was directly related to the Nobel Prize, Jaeger said; he was a co-author of the central theoretical result behind the Nobel, called the “CHSH inequality,” along with Horne, Clauser and Richard A. Holt.

Jaeger credits Shimony’s work as the magnet that pulled him to the East Coast, and said Shimony’s work focusing on the intersection of philosophy and physics, now referred to as experimental metaphysics, was “uniquely a BU thing.”

Jaeger shared that he was incredibly happy to hear the news of the Nobel, and said that “giving the Nobel in this subject is extremely important because [Shimony] was ahead of his time in the area of fundamental foundations of physics.”

Jaeger’s love of science began to develop in his high school chemistry class. He remembers thinking, “Well this quantum business is weird and interesting, so this is probably what I am going to do.”

His newfound passion pushed him to pursue a triple major in mathematics, physics and philosophy at the University of Wisconsin and, eventually, graduate studies at Boston University.

When Jaeger joined Shimony, he said, Boston University was far ahead of the curve in the foundations of physics. Most of the initial mathematics, lab testing, and trials had already been completed by the time Jaeger and Shimony began working together, so Jaeger saw this as an opportunity to focus on the niche fields of quantum information and quantum metaphysics.

As Jaeger dove deeper into his research, two overarching questions paved the future of his doctorate studies and his current work at BU.

“For me it was the question of … are these [particles] always connected so that, in a certain way, they’re just one thing? How else can you explain this connection between two things? They must be one thing, right? And so that’s what my work is about,” he said.

With Shimony, and prompted by Zeilinger, he proposed another quantum equation, an equality going beyond the CHSH inequality, that trades off an interference effect in a single particle with one in the pair it belongs to, something which should happen if the two particles of a pair are really a single object. It was shown experimentally to be correct by a group of Boston University professors in the time between when his PhD was granted and when he returned to BU to work with Sergienko, with whom he then went on to demonstrate its use for practical quantum cryptography.

Eventually, Jaeger obtained two patents in quantum computing, had his own lab in Cambridge that used them, and built the lab and was head of research for a start-up company in 1999 that produced 5-qubit quantum computers – a type of computer that uses subatomic particles to perform functions more efficiently.

After returning to BU as a professor, Jaeger helped explain the significance for quantum information processing of the Nobel work, while remaining in communication with the Nobel winners about its deeper, philosophical implications, and held an international conference on the topic at BU in 2006 together with philosophy professor Alisa Bokulich.

Jaeger receives the Dr. Ismail Sensel Award from CGS Dean Natalie McKnight in September 2023. He previously won the award in 2007. Photo by Ziyu (Julian) Zhu.

In his current role as associate professor of natural sciences and mathematics at CGS, Jaeger was awarded this fall for the second time with the The Dr. Ismail Sensel Award, which recognizes and honors outstanding CGS professors.

While his course curriculum does not focus on his specific field of research, Jaeger is still carrying on the legacy of Shimony and his work in experimental and quantum physics.

Jaeger opted to teach in CGS because of the interdisciplinary curriculum and so that he could pursue physics, philosophy, and the history of science at the same time.

During his time as a professor, Jaeger has been able to share his research with a diverse group of students, faculty, and administrators who may or may not have a background in physics, which he says is an uncommon privilege.

“Intellectually, this is the most interdisciplinary part of the university,” he said. “That’s why I’m at CGS and that’s why I think many people are flourishing [here,] because of its interdisciplinary nature.”