Particles, Skateboards and Ellipsoids, Oh My!

Evan Variano

Evan Variano

Abby Blair, Maroon-News Staff

Currently in the Physics and Astronomy department, candidates are competing for a sought-after position to become a professor on the hill. Evan Variano, the second of the three candidates vying for a position in the Physics and Astronomy department, made a positive impression on the audience with his Tuesday, February 5 presentation on fluid dynamics, complete with 3D animations and a plethora of colorful graphs and images. The title of his presentation was “Kinematics of Non-Spherical Particles Suspended in Turbulence at Inertial and Dissipation Scales.” Variano came to Colgate from University of California Berkeley, and his research focuses on how particles move in a fluid: how the push and pull of water currents and turbulence effect particles of different shapes and forms.

While the title of the presentation makes the subject matter seem quite inaccessible, Variano explained his work in terms that could be understood by both students and professors in the audience. Variano started the presentation by acknowledging the work of the graduate students who worked with him on his research, and then got right into the motivations for pursuing this topic.

Variano described how these particles move by comparing them to a skateboarder; when someone on a skateboard hits a rock, they wobble a bit and can either straighten out or crash. The wobble of a skateboarder is comparable to a fluid instability, and the crash is analogous to fluid turbulence. The difference between uniform movements in fluids and chaotic movements.

The key factor in his research is the shape of the particles in the water. He focuses mainly on ellipsoids, 3D ovals, of different sizes. “Inertial scales” are objects that are relatively small, and “dissipation scales” are objects that are relatively large compared to the fluid currents that are affecting them. The motion of these particles is very chaotic and seems fairly arbitrary at first, but Variano showed how you can actually calculate the forces acting on the particle and how they affect the particle’s motion. He demonstrated this through a series of animations to help the viewers visualize the forces that he explained.

Senior Jas Schuldt was impressed by Variano’s ability to make a challenging topic accessible to the audience.

“I thought he explained a very complicated subject really, really well. I found him humorous and engaging,” Schuldt said.

While it could be easy to lose an audience when attempting to explain such complicated subject matter, Variano’s sense of humor kept the audience engaged. He had the audience laughing throughout his entire lecture without distracting from the content he presented. His casual comments and jokes resonated with the crowd and kept everyone engaged. Sophomore Daniel Dougherty noted that the candidate’s humor was what stuck out to him.

“The first thing that struck me was how funny he is in a very distinctive way, which the students and professors in the physics department can really appreciate uniquely,” Dougherty said.

While Variano was very thorough in explaining his research in the beginning of his presentation, toward the end he glossed over a lot of information as he ran out of time to present it. However, most of the audience walked away with the feeling that they had a decent grasp on the concepts he presented and his research overall. The final candidate presented on Tuesday, February 12 to the Colgate community.

Contact Abby Blair at [email protected].