Last year, Sigurdur Thoroddsen, professor of mechanical engineering at KAUST, and his former postdoctoral fellow Meng Shi captured an image that turned a simple fluid experiment into something almost alive. What they saw looked eerily like a cluster of spider eyes staring back at them.
The effect came from a Marangoni-driven flow — a phenomenon where tiny differences in surface tension make a liquid move and organize itself into mesmerizing patterns. It’s the same physics behind the way oils spread or how droplets interact on a surface.
“It came as a total surprise,” said Prof. Thoroddsen. “We were studying a flower-like pattern that appears when a water drop impacts glycerin. As we slowly varied the surface tension between the two liquids, these multiple ‘eye-like’ structures emerged. You can actually see them forming gradually in the high-speed video — it’s a little spooky!”
The image was selected for the American Physical Society’s Gallery of Fluid Motion, one of the world’s most prestigious showcases celebrating the beauty of fluid dynamics. Later, the APS featured it in its “Thirteen Images That Reveal the Spooky Side of Physics” collection for Halloween — proof that physics can be as haunting as it is precise.
So, a word of warning to all students:
If you gaze long enough into fluid dynamics, fluid dynamics might just gaze back at you.
A happy and spooky Halloween from the PSE Division!