Seventy-four-year-old Ken Holdeman is attending the University of Minnesota for one purpose — to immerse himself in quantum entanglement, a physics concept that has intrigued him for years.

In 2009, Holdeman encountered a Scientific American article that included comments on quantum entanglement, and he said to himself, “There has to be a better way.”

Three years later after retirement, Holdeman signed up to audit his first quantum mechanics class on the Twin Cities campus to go further on this complicated physics issue. Eight years later, he is still trying to solve it, the Minnesota Daily reported.

As of fall 2019, Holdeman is one of over 500 senior citizen students ages 62 or older who are taking classes on campus under the Senior Citizen Education Program. Students in this program pay $10 per credit and audit classes for free on the Twin Cities campus.

Like Holdeman, many come back with different purposes — some want to continue their interests outside of their professional career and others hope to refresh themselves. For Holdeman, that interest was quantum entanglement.

Quantum entanglement is credited to a 1935 paper co-authored by Albert Einstein and colleagues that is popularly referred to as the Einstein–Podolsky–Rosen paradox. The thought experiment involves particles interacting physically and when the properties of one, such as its polarization, are measured, the other’s properties can be predicted.

Different scholars and groups find this experiment intriguing, but few people understand the math behind it in enough detail to ask questions. Holdeman said he has insights of how the math works, so he has worked with University professors to pursue further developments.

Holdeman finds that classes outside of the physics department help him understand quantum entanglement. He once took a class called Philosophy of Quantum Mechanics.

“When I took it, I found my people,” Holdeman said, adding that he had many “wonderful discussions” with several classmates.

University philosophy professors Samuel Fletcher and Jos Uffink have helped with Holdeman’s research. One of them volunteered to help him and introduced him to several articles, where Holdeman said he furthered his understanding and improved the depth of his ideas.

Holdeman said he is not sure his ideas to better understand quantum entanglement are correct, but there is a chance they may be “revolutionary.”

Holdeman was a computer science master student at the University back in the early 1970s and worked at Seagate Technology, a data storage company, for 28 years before retirement.

“My lifelong experiences have helped me understand nuances in why professors approach subjects the way they do,” Holdeman said. “I’ve found it fascinating to compare how classes were taught years ago and how students are responding in today’s classes.”

In addition to pursuing quantum entanglement, Holdeman took psychology professor Daniel Kersten’s fall 2018 class Intro to Neural Networks, which discussed connections between artificial intelligence and psychology. He now helps with Kersten’s presentations to better align the material with cutting-edge neural network software development using his coding experience in Python.

“Lifelong learning is a wonderful ambition to have,” Kersten said.

It is rare to find a student like Holdeman who maintains an interest in the content of the course after the course is over, Kersten said.

“Ken is pretty special,” Kersten said.

Holdeman plans to share what he has discovered about quantum entanglement so far with arXiv, an open-access archive.