Senior citizen 89 year-old Manfred Steiner of East Providence, Rhode Island, recently proved the adage that age is just a number, according to Association of Mature American Citizens [AMAC].

Steiner was already a Doctor of Medicine who also holds a doctorate in biochemistry, thanks to the urging of his family when he was a young man; however, he said, physics was always his passion. And so, after retiring as a hematologist at Brown University at the age of 70, he enrolled at Brown to earn a degree in physics.

“Even though I am old, I would like to continue with physics,” he said. “And even after writing and publishing this paper [his thesis], I want to continue my research. I always tried to keep my brain sharp. Physics certainly helped me do that.”