Olympic Ice is Different in a 'Frozen Light'
Scientists and spectators at the Winter Olympics are all seeing the same ice and snow, but one scientist can see exactly how different it can be for each sport, by using light.
Snow and ice can look like long tubes or tiny ping-pong balls. NASA scientist Peter Wasilewski is using "polarized" light to see if snow and ice is the right texture for different Olympic sports, and also creating beautiful colored pictures of the snow and ice. It's important to see the shapes of the snow and ice because in Olympic sports, they have to be different for each sport, whether skiing or snowboarding, figure skating or hockey. The shape of snow for example, can be tiny snow flakes or snow balls. Typically, snow flakes are not good for skiers, and can slow them down. By looking at the snow with polarized light, Wasilewski can see what type of snow is on the ground and if its right for skiing.
Images above: The image on the left shows mostly natural snow crystals with some man-made snow underneath. The image on the right shows the snow-ball shaped man-made snow that comes from snow guns. Credit: Eric Erbe/USDA
Wasilewski, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md. said that light is like a wave, and one kind of wave is vibration. Ordinary white light vibrates in many directions, but a polarizing filter (like in sunglasses) blocks all light except that which is vibrating or moving in one direction. For example, when light reflects off a surface like glass, water, or the surface of a road, the light is "polarized," or just vibrating in one direction. Un-polarized light is like the light emitted by the sun, or by a lamp in the classroom, and goes in all directions.
The colors and patterns in images produced using polarized light define the type of ice and snow being studied. A core from an ice rink that had been recently skated on would show multi-colored granules, like snow dust, created from the sharp blades of the skates cutting into the ice. Below that would be what appear to be vertical, cylindrical ice crystals. Those crystals extend down to the next layer on which lines and circles (used for hockey) are painted directly on the surface of the ice. Underneath that layer is another vertical layer of multi-colored crystals extending down to the painted white surface we all associate with ice rinks. If the surface of that quarter inch of ice were not painted white, the ice would appear dark to the viewing audience. Finally, below that is the thin layer of ice created from water sprays that seal the concrete slab.
Image above: Cross-section core taken from the Lake Placid ice arena shows the layers of ice and how the crystals differ from layer to layer. Click image to enlarge. Credit: Dr. Peter Wasilewski
"Ice is different for each Olympic sport," Wasilewski said. "The ice is softer for figure skaters than it is for hockey players. Figure skaters need to dig in with their toe picks for jumps. Ice hockey players want the hard ice that makes the ice fast and easier to skate on. With a microscopic look at the ice using the spectrum, I'm able to see how the ice differs."
Wasilewski realized that color and shape of ice and snow changes depending on the thickness and direction of the ice. He got started by just playing around, making ice crystals in his refrigerator and photographing them. From there, the colorful art of snow and ice he calls "Frizion" was born.
Images above: This collage shows four of Dr. Wasilewski's art compositions. Credit: Dr. Peter Wasilewski
Goddard Space Flight Center