Alabama A&M University welcomed Nobel Laureate Dr. Arthur B. McDonald to campus Friday as the distinguished speaker for the 25th Putcha Venkateswarlu Memorial Lecture, where he shared insights into the origins of the universe, the elusive nature of neutrinos, and his journey from the depths of an underground laboratory to encounters with renowned figures such as Stephen Hawking and the cast of “The Big Bang Theory.”

McDonald, Gray Chair Emeritus Professor in Particle Astrophysics at Queen’s University in Kingston, Canada, was awarded the 2015 Nobel Prize in Physics, which he shared with Dr. Takaaki Kajita “for the discovery of neutrino oscillations, which shows that neutrinos have mass.” His pioneering work as Director of the Sudbury Neutrino Observatory (SNO) in Ontario fundamentally changed how scientists understand the composition of the universe.

A Return to Huntsville

McDonald opened his lecture in Dawson Auditorium by telling the audience this was not his first visit to Huntsville. He first came to the Rocket City 62 years ago – during what he described as a turbulent time in the American South.

“It was the summer of 1963, just three weeks before the March on Washington, months before President Kennedy’s assassination, and a year before the Civil Rights Act,” McDonald recalled. “I came with a friend from Nova Scotia who was helping set up NASA, and we were confronted by several local people who accused us of being Yankees. Things escalated until the police were called. It was a tense time.”

Reflecting on his return, McDonald said he was moved by the progress both the region and Alabama A&M have made.

“To come back now and see this thriving university providing world-class education and research opportunities – it’s truly inspiring,” he said. “The progress that has been made here is remarkable.”

Exploring the Universe from Underground

McDonald described his years of work at SNO, a working nickel mine two kilometers underground and one of the world’s deepest and cleanest scientific facilities. Its 10-story spherical detector, filled with about 1,000 metric tons of heavy water and surrounded by 9,500 light sensors, was built to detect solar neutrinos – subatomic particles that rarely interact with matter. Researchers must shower and change into clean uniforms before entering – complete with hair and shoe covers – to avoid contaminating the sensitive experiment.

When theoretical physicist Stephen Hawking visited the lab in 2012, special precautions had to be taken.

“Stephen couldn’t go through the usual process,” McDonald explained. “So, we vacuumed his wheelchair thoroughly and covered him carefully before taking him down. He was very good-humored about it. He was truly a remarkable man” he added. He did all his most important work after becoming disabled.” He was an inspiration to us all.”

Unlocking the Secrets of Neutrinos

“Neutrinos are extremely elusive,” McDonald explained. “They only interact through the weak nuclear force, making them incredibly hard to detect. We had to build a massive detector underground just to observe one per hour from the sun.”

The SNO team’s findings changed the scientific paradigm: instead of all solar neutrinos being one flavor, they found they oscillate (or change type), which implies neutrinos have mass.

 “We now have a general understanding of the evolution of the universe since the Big Bang,” McDonald said. We now know the universe’s makeup – roughly 70 is percent dark energy, 26 percent dark matter, and only 4 percent ordinary matter. “But there are still substantial questions to be answered. Some can be explored in low-radioactivity labs like SNO, while others require the expertise and satellite technology that NASA and Huntsville can provide.”

Speaking of the “Big Bang Theory,” McDonald was able to visit the set of the popular show because Professor David Salzberg at UCLA and technical advisor to the show, was his former student at Princeton. “I was invited to be “Geek of the Week,” said McDonald. “I truly had a great time meeting the cast.”

Inspiring the Next Generation

During his visit to AAMU, McDonald toured the physics facilities and spoke with students about their research and the University’s integration of artificial intelligence in the curriculum.

“I was very impressed by Alabama A&M’s physics program,” he said. “You’re preparing students to make real contributions to the next generation of science.”

Students described the lecture as both inspiring and surreal.

“Having the chance to hear from a Nobel Prize winner was incredible,” said Bria Watkions, a sophomore biology major at Oakwood University from Bermuda. “His lecture about how much we still don’t know about the universe was fascinating. You don’t get this opportunity every day.”

Marcus Williams, a two-time Alabama A&M alumnus and Ph.D. student in physics, said McDonald’s lecture offered valuable perspective.

“Hearing Dr. McDonald talk about dark matter and the unknown parts of the universe reminded me how much there still is to discover,” Williams said. “He emphasized that we only understand a small fraction of what’s out there, and that was inspiring. It motivates me to keep pursuing research and innovation.”

As he concluded, McDonald praised Alabama A&M’s legacy and vision for the future.

“Progress in science and society doesn’t happen overnight,” he said. “But when I look around this university and see what’s being accomplished here, I know the future of discovery is in good hands.”