Juan Pedro Ochoa-Ricoux, UC Irvine professor of physics and astronomy, and James Owen Weatherall, Chancellor’s Professor and department chair of logic and philosophy of science, have been elected as fellows by the American Physical Society, a recognition granted to physicists who have made exceptional contributions to the field of physics.

Ochoa-Ricoux was recommended by the APS’s Division of Particles and Fields for his leadership in precision neutrino oscillation measurements and key contributions in the Daya Bay, JUNO and DUNE experiments to advance next-generation neutrino physics.

As a postdoctoral scholar at Lawrence Berkeley National Laboratory, Ochoa-Ricoux worked on the Daya Bay experiment, which consisted of eight detectors to observe neutrino emissions from six nuclear reactors in China. The project demonstrated that the value one of the parameters governing neutrino oscillations known as theta-13 was not zero, “a discovery with big implications for our field,” said Ochoa-Ricoux.

In 2014, Ochoa-Ricoux joined the JUNO project which also detects neutrinos from nuclear reactors in China, although with a much larger detector. JUNO scientists have provided the world’s most precise measurements of three neutrino oscillation parameters and an indication of how neutrino masses are ordered. Ochoa-Ricoux was one of the two people responsible for coordinating the production of these results.

Ochoa-Ricoux’s work on the JUNO project continues, and he has also joined DUNE, the flagship, next-generation, U.S.-based particle physics experiment. In this project, the world’s most powerful neutrino beam will be sent underground from Fermilab near Chicago to a former mine in South Dakota. DUNE’s detector will produce detailed, three-dimensional images of neutrino interactions.

“It feels wonderful to have been named a fellow by the American Physical Society,” Ochoa-Ricoux said. “I am humbled to think that I have been able to contribute my own little grain of sand to the great edifice of physics, helping to push the frontiers of our knowledge a little bit farther.”

Weatherall was chosen as an APS fellow by his peers in the society’s Forum on History & Philosophy of Physics. He was recognized for his “substantial contributions to the foundations of classical field theories and the philosophy of physics; distinguished mentorship, leadership, and service to the discipline; and conveying physics to broad public audiences through acclaimed books,” according to the society.

A philosopher of physics, science and mathematics, Weatherall’s work focuses on gravitation, cosmology and the concepts underlying scientific theory development. He has contributed important analyses to clarify the structure of space-time theories and resolve conceptual puzzles in general relativity, Yang-Mills theory and the philosophy of modern physics.

He’s the author or coauthor of three books: The Physics of Wall Street: A Brief History of Predicting the Unpredictable (Houghton Mifflin Harcourt), Void: The Strange Physics of Nothing (Yale University Press), and The Misinformation Age: How False Beliefs Spread (with Cailin O’Connor, Yale University Press). He has published more than 70 research articles and book chapters in journals spanning the philosophy of science, physics and mathematics.

Weatherall’s current research projects address foundational questions in classical and quantum field theories, the philosophy of cosmology and in emerging philosophical issues related to AI in science and society. He is also writing a scientific biography on John von Neumann, a leading 20^th century mathematician. This past year, Weatherall was elected to the American Academy of Arts and Sciences.

“I am so pleased and grateful to be honored by the American Physical Society,” he said. “Philosophy of physics has at times had an awkward relationship with the discipline of physics. I think it is significant that in the past few years, the APS Forum on History of Physics has changed its name to include philosophy and has begun to elect fellows in recognition of their work in philosophy. I am proud to be among the first to be selected since that change.”

Ochoa-Ricoux and Weatherall are among 153 scientists from around the country to be inducted into this year’s cohort of American Physical Society fellows.