- September 21, 2026
- By Karen Shih ’09
The bottle of olive oil on Charles Clark’s desk isn’t for drizzling on his lunchtime salad, nor is the club soda on his windowsill for sipping between experiments.
Instead, these pantry staples can illustrate some basics of quantum mechanics.
Shining different-colored laser pointers into clear coconut oil and green olive oil, the University of Maryland physicist shows how these lights operate at different energy levels; red is the lowest and violet is the highest that a human eye can see. While the red laser looks the same whether shone on a plain white surface, into each pool of oil or through the bubbly water, the violet beam behaves differently. The chemicals in the liquids absorb the invisible wavelengths—chlorophyll in olive oil and quinine in tonic water—causing them to fluoresce and turn bright orange or blue.
“This was one of the outstanding mysteries of physics” in the early 1900s, said Clark. “Why does the color change here, but not there?”
This kid-friendly experiment is a long way from the complex quantum science and technology that Clark has spent his career examining, from its applications in computing and communications to explorations of ultracold matter and light-wave interferometry. For 40 years, he’s served across U.S. civilian and military agencies, and is now an emeritus fellow at the Joint Quantum Institute (JQI), a partnership between the National Institute of Standards and Technology (NIST) and UMD that he previously co-directed.
At its heart, quantum science is about understanding light and matter and their interactions at the tiniest scales. Its applications range from super-secure cryptography to speedier drug discovery via molecular simulation, made possible by powerful quantum computers that governments and firms around the world are racing to be the first to deploy. And this week, the Quantum World Congress convenes at UMD, bringing together leaders from academia, government and industry.
But take a look around Clark’s Atlantic Building office and you’ll see his less serious side, and perhaps learn why he has a cartoon poster with his face on it, why he sneaked a couple pairs of 3D glasses from the movie theater and how he adapted to life aboard a massive aircraft carrier.
A tiny superhero
Look a little closer at this 1960s-era comic book poster, and you’ll see Clark’s face incorporated into the art—in this case, as the bad guy holding Atom, a superhero and physics professor himself. “One of the subjects I was involved in as a research scientist at NIST was the optical cooling and trapping of light,” said Clark. Inspired by this work, former JQI colleague Philip Schewe found the perfect edition of “Atom” and created the poster as a gift.
Einstein’s manuscript
A bound copy of Albert Einstein’s 1912 paper on the special theory of relativity shows the physicist’s handwritten text alongside typewritten words. It was a gift from Clark’s brother; while his father was an electrical engineering professor at the University of Washington, Clark was the only one of his four brothers to become a scientist.
It’s actually an earlier Einstein paper that relates most directly to Clark’s work today: “Einstein’s insight was that this color is correlated with the energy of the photon of light. His 1905 paper contains the first usage of the word ‘quanta’ as we use it now.”
3D glasses
Holding a pair up to his computer screen, Clark turns the glasses in a circle, showing how first one lens goes dark, then the other, demonstrating polarization, another property of light. Because the lenses are polarized differently, when movie theaters project different views of the same image, the glasses only allow one view in each eye to create the 3D effect.
Lab Snacks
The bright-red box decorated with the image of a mutant-green dog is from Thorlabs, the company that manufactures the main equipment needed to do atom cooling and trapping for quantum science, said Clark. “They had the genius to ship boxes of snacks with every expensive piece of optics that’s ordered by the graduate students and postdocs.”
Theodolite
Before lasers were invented, scientists used these telescope-like instruments to align two pieces of equipment for optics experiments (out in the field, theodolites were used for land surveying). Clark inherited this one from an old lab that was being taken apart. “These days, if you do work around your house, you can get a laser version of this,” he said.
“Honorary Lincoln Navigator” certificate
In the early 2010s, Clark served as a program manager at the Office of Naval Research, which allowed him to spend a week aboard the USS Abraham Lincoln, an aircraft carrier. “It’s for research managers to familiarize oneself with actual life in the Navy, and then, if there are technology needs, maybe you pick up on some of those. Know your customers,” he said. The nuclear-powered vessels are remarkable because they don’t need to stop for refueling or to desalinate water for the 5,000 people on board—but admittedly, “the quarters are cramped.”