Well, how did I get here?

There’s a whole universe in there

Raoul Kopelman and Panos Argyrakis stand together outside on the U-M campus.

In Fall 2022, Kopelman and his former PhD student Panos Argyrakis, PhD ’79, visited campus. Argyrakis is the first doctoral candidate at U-M to write and print his thesis on a computer. (Image: D. Holdship.)

When Michigan Ross professor Shirli Kopelman invited me to her Arb-adjacent deck last fall to meet her father, I could not believe my good fortune. While I have no intellectual understanding of physics, applied or otherwise, I am fascinated by the workings of the universe and would never pass up the opportunity to meet Raoul Kopelman (1933-2023). I knew then what a rare gift it was to share his time; imagine if I could actually speak his “language.”

The world-renowned scientist, who joined the U-M faculty in 1966, was 89 years old when he passed away July 20. He was still teaching in recent months and held the Richard Smalley Distinguished University Professor of Chemistry, Applied Physics, Biophysics, Biomedical Engineering, and Chemical Biology at U-M.

I won’t pretend to understand what this means, but Kopelman was an expert on photonics, laser and bioanalytical chemistry, chemical physics, catalysis, nano-materials, and nano-devices. In plain English, he was interested not only in the teeny, tiny, sub-micro particles that comprise our universe. It was the space between the teeny, tiny, sub-micro particles he really cared about.

In a word: Kopelman was nano before nano was cool.

Play time

On the cool evening when I met him, the professor was anxiously awaiting the arrival of his one-time student and longtime friend Panos Argyrakis, PhD ’79. Argyrakis was visiting Ann Arbor from Greece’s University of Thessaloniki where he is a professor of computational physics. Kopelman was sure his friend would come with an agenda: the need to solve some conundrum involving molecular crystals, nanoparticles, complex systems, or some other puzzle incomprehensible to the less-evolved brain.

“His eyes are twinkling,” said his daughter, an expert in negotiations. As she filled his water glass, she said, “It’s like he’s getting ready to play and thinking, ‘What will we do when Panos gets here?’”

What do you see?

A group of people stands outside on the Michigan campus.

Kopelman chats with students in 2022. (Image D. Holdship.)

It’s mind-boggling to consider the dramatic progress in computing since Kopelman first plugged in. He arrived at U-M when the University’s sole computer consumed the entire floor of a building. He pioneered the use of computing in the chemistry department, despite detractors who dubbed the effort “anti-educational.”

Kopelman is perhaps best known for developing the Hoshen-Kopelman algorithm, a simple and efficient algorithm for labeling clusters on a grid, where the grid is a regular network of cells, with the cells being either occupied or unoccupied. The algorithm’s practical application is so widespread in modern technology that scholarly citations of Kopelman’s work still pop up every day on Google Alerts. His 1976 paper “Percolation and Cluster Distribution. I. Cluster Multiple Labeling Technique and Critical Concentration Algorithm” has been cited thousands of times since publication.

Alumni, friends, and colleagues who worked with Kopelman throughout his career represent key advances in computer science: His former students include the Nobel laureates Richard Smalley (for whom his U-M professorship is named), Eric Betzig, Roald Hoffman, and Arieh Warshel.

Still working

As he stared down his 90s, Kopelman continued to force scientific breakthroughs in the burgeoning field of nanomedicine, covering novel diagnostic and therapeutic techniques for cancer and heart disease. Implanting nanoparticles that precisely and specifically target and kill dangerous cells, the technology uses noninvasive and otherwise harmless red light, instead of high-energy lasers, X-rays, or gamma rays. With collaborators in the Medical School, he recently applied this technology to treat cancer, as well as heart arrhythmia, in rodents and sheep.

Kopelman and a group of people outside on campus.

Michigan Ross professor Shirli Kopelman, (left) with her father and Argyrakis. (Image: D. Holdship.)

Throughout my encounter with this genius, I marveled at the circumstances that placed me here in casual conversation with one of modern technology’s most brilliant minds. Imagine the scientists who would froth at the chance.

And as I pressed him about his early trailblazing days, I realized Kopelman was more interested in talking about his future. (How inspiring!) He did tell me his family had fled Vienna during World War II to escape the Nazis. They settled in Tel Aviv when Kopelman was five years old.

“I would stare at the night sky and could see galaxies beyond the Milky Way,” he said. But he was always more interested in what he couldn’t see. And when he read The Fantastic Voyage by Isaac Asimov, Kopelman set his sights on the undiscovered and as-yet-unnamed world of nano. The book is about a research crew reduced to a microscopic fraction of their original size, boarding a miniaturized atomic submarine and being injected into a dying man’s carotid artery.

As Kopelman described the latest modern-day breakthrough he helped produce — in which nanoparticles can travel with precision through a patient’s body to directly seek, target, and address a problem – that playful twinkle in his eye returned.

“I just wanted to make a tiny submarine,” he said.
(Lead image: The author never expected to discuss the universe with Raoul Kopelman. And she never expected to stand at midfield in Michigan Stadium either. It’s all in a day’s work for this Spartan working at the University of Michigan. Image: S. Busch.)


  1. Diane Kaplan Vinokur - MSW, 1972, PhD,1975

    Thanks for capturing the breadth, heights, and depth of of Professor Kopelman’s professional life. At his recent burial, the attendees further reflected the many kinds of people on whom he had a strong, positive and lasting impact—his family, friends, neighbors, colleagues, and students from around the world whom he mentored during their dissertations and careers. A memorial will be held in the future at The University of Michigan.


  2. Rachela Popovtzer - post doc 2008

    I am deeply saddened to hear about the passing of Prof. Kopelman, a truly exceptional man whose loss is felt profoundly by all who had the privilege of knowing him. He was not only a brilliant professor, but also a charming, kind-hearted man with a big soul, who touched the lives of countless students through his guidance and mentorship. His impact as a mentor was immeasurable, and his dedication to promoting the growth of his students was evident to all who crossed his path. Prof. Kopelman was like a lighthouse, firmly rooted on the ground, providing unwavering support and guidance to those around him while his vision reached the sky, inspiring us to dream big and achieve greatness. We will always remember his legacy of wisdom, kindness, and inspiration, and find solace in the memories of the profound influence he had on all of us. His memory will forever live on in our hearts.


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