Ramanath Cowsik, PhD, was installed as the James S. McDonnell Professor of Space Sciences in Arts & Sciences at Washington University in St. Louis at an Oct. 7 ceremony in Holmes Lounge, Ridgley Hall.
Cowsik’s contributions to neutrino physics and to understanding dark matter in the universe have earned him international recognition, said Chancellor Mark S. Wrighton in his opening remarks.
“This special professorship was established in 1963 by the McDonnell Aircraft Foundation to honor its founder, James S. McDonnell, a pioneer in aviation who served as a Washington University trustee and was chairman of the board in the 1960s,” Wrighton said.
John F. McDonnell, James McDonnell’s son, then rose to speak. He remarked that his father, often called Mr. Mac, decided to major in physics when he entered Princeton University in 1917.
“If Mr. Mac were here today, he would want to understand in detail Professor Cowsik’s research and would quiz him about supernovas, pulsars, black holes and dark matter, none of which were generally accepted phenomena during my father’s lifetime,” McDonnell said.
“Ram Cowsik is often called the father of astroparticle physics, a branch of particle physics and a relatively new field of research emerging at the intersection of particle physics, astronomy, astrophysics and cosmology,” said Barbara S. Schaal, PhD, dean of the Faculty of Arts & Sciences, who introduced Cowsik.
In his address, “From Neutrinos to the Cosmos,” Cowsik, of the Department of Physics, in Arts & Sciences, said the tradition of star gazing in his family goes back to 1700. His forefathers came from a small village called Edaiyattumangalam on the banks of the river Cauvery in South India. “They were classical scholars, calendric astronomers and keepers of the almanac and helped the people around them in scheduling dates for rituals, for sowing and for reaping,” he said.
He also took the occasion to remember his grandfather, orphaned at the age of 4, who still managed to graduate in engineering and “whose indomitable courage and dedication to social service and the highest intellectual values” had been his inspiration.
Early in his career, Cowsik said, astronomers were preoccupied by the problem of missing mass. Galaxies were shown to be moving so rapidly that they should have been flung outward from galaxy clusters — unless the gravitational attraction of unseen matter (dark matter) was holding them in place. But what was the dark matter?
Some astronomers nominated brown dwarfs, dim stars not dense enough to ignite nuclear fusion. Cowsik made the bold suggestion that the mass might instead come from neutrinos or other weakly interacting particles.
The standard model of particle physics assumed neutrinos were massless, but Cowsik showed that if neutrinos did have a small mass, there were so many of them that they would dominate the gravitational forces in the universe.
Neutrinos, he explained, are the most penetrating of the fundamental particles, so weakly interacting that they can go through the Earth almost unimpeded.
It turned out he was right: beginning in 1998, a series of experiments showed that neutrinos have mass, although scientists still struggle to measure their masses accurately.
Dark matter, however, is still a mystery, but many astronomers believe the solution may be weakly interacting massive particles, or WIMPs, particles that have many of the properties of neutrinos but are far more massive.
“The basic idea is that the universe is dominated not by the kind of matter that you and I can see,” Cowsik said, “but by a different kind of matter and that there is an intimate interconnection between the smallest scales and the largest, between neutrinos and cosmology.”
We really can see the whole world in a grain of sand, he said in conclusion, quoting the poet William Blake.
Cowsik earned his bachelor’s degree in physics, chemistry and mathematics with minors in Sanskrit and English from Mysore University, India, and a master’s degree in physics under noted spectroscopist N.R. Tawde. He then joined the Tata Institute of Fundamental Research and worked under the guidance of Yash Pal to earn his doctoral degree from Bombay University.
After serving briefly at the Institute for Theoretical Astronomy in Cambridge, England, and the University of Chicago, he became a member of the teaching faculty at the University of California, Berkeley, and eventually returned to the Tata Institute, where he rose to the level of distinguished professor. He joined the WUSTL faculty in 2002 and serves as director of the McDonnell Center for the Space Sciences.