May 11, 2011

Photon Sciences Daughters, Sons Learn About Light

More than 40 children of Photon Sciences employees learned on April 28 about a subject near and dear to their parents' hearts: light. As part of "Take Our Daughters and Sons to Work Day" the kids got a first-hand look at the NSLS as they journeyed across the experimental floor to explore the properties and usefulness of light at different wavelengths.

The activities, led by NSLS graduate student Alvin Acerbo (Stony Brook University) and supported by the User Administration Office and numerous Photon Sciences volunteers, started with an introduction by biophysical chemist Lisa Miller and a brief safety note from Andrew Ackerman. After learning about how light works in everything from remote controls to microwaves, the children set off in groups for a series of hands-on experiments.

To explore visible light, the children used glow sticks to watch chemiluminescence in action. Once the stick is cracked and its internal chemicals are allowed to mix, it glows brightly. It shines even brighter when dipped in a glass of hot water, the children discovered, and becomes duller when placed in cold water. The reason: the speed of the reaction process depends on the temperature. The children got to take their glow sticks home, where, if the lesson was learned, they quickly put them in the freezer.

With a set of special beads that change color in the presence of ultraviolet light, the kids learned about the importance of sunscreen. When blocked by sunscreen slathered on a clear sandwich bag, the beads remain white. When exposed, they change color - much like unprotected skin would on a summer day.

At NSLS beamlines U2B and U10B, the children used a different type of light - infrared - to study the chemical composition of four types of milk: half & half, whole, 2 percent, and skim. After preparing a slide with a drop of each type, Fourier transform infrared microscopy was used to determine each sample's fat, protein, and sugar levels. The children used this data to match the types of milk with the samples.

As a special treat, two of those milks - half & half and whole - were mixed with sugar, vanilla, and liquid nitrogen to make a super cold and foggy batch of ice cream for everyone to eat.