Gummy Bears, laser pointers demonstrate concepts at celebration of light

Grandparents, parents and children crowd around the fluorescence table Saturday at Adventure Science Center. (Heidi Hall/Vanderbilt University)

Children and their parents crowded against the table at Adventure Science Center, eyes glued to biomedical engineering grad student John Nguyen and the green laser pointer pressed to his index finger.

“Can you see the light come through my finger?” he asked.

“No!” came the chorus of voices back — and it’s true, the green light was absorbed.

Nguyen picked up a different laser and did the same thing, his finger emitting a red glow. “Does anyone know what’s inside my finger that’s red and allowing the laser to pass through?” he asked.

Brief seconds of silence passed before one brave boy spoke up. “Blood?”

That was right, and Nguyen explained how the demonstration carried over into more complex science, specifically, the way a pulse oximeter works to let patients know the oxygenation levels in their blood.

That was the point of Saturday’s International Year of Light celebration, said Anita Mahadevan-Jansen, Orrin H. Ingram Professor of Biomedical Engineering, professor of neurological surgery and founding director of The Biophotonics Center at Vanderbilt. Engineers engaged visitors with simple demonstrations using flashlights, glow sticks and Gummy Bears, then taught them higher-level concepts.

“It forces the students to describe engineering concepts to everyone from a 3- or 4-year-old to the moms, dads and grandparents — who ask the most interesting questions,” she said.

The event was sponsored by The Biophotonics Center, Vanderbilt University and the student chapter of SPIE, the international society for optics and photonics, to mark UNESCO’s declaration of 2015 as the International Year of Light and Light-Based Technologies. The tables, staffed by undergraduates, graduate students and an alumna, covered absorption, scattering, diffraction, florescence and fiber optics.

A nearby constellation display worked well to demonstration diffraction. (Heidi Hall/Vanderbilt University)

At the fiber optics table, Amy Shah, a graduate student in biomedical engineering, watched as children ran their hands along tiny, colorful bits of cable.

“The internet works using fiber optics, so it transmits information as light,” she said. “This is much faster than using electrical energy because it moves at the speed of light.”

Organizer Jeremy Ford, a graduate student in biomedical engineering, said he hoped parents would take some of the experiments home to keep their children interested in engineering.

“When you can turn everyday items into something that is scientifically relevant, it’s so cool,” he said.


Heidi Hall, (615) 322-6614
On Twitter @VUEngineering