Effects of Light Shielding and Wavelength on Light Pollution

The objective of this experiment was to reduce the amount of light pollution in the sky. The data from this experiment may allow astronomers to study the stars to study them in closer, more convenient locations rather than travel to remote areas.

This experiment was conducted by projecting stars on the ceiling of a dark room. The stars were then obstructed by a second light that emitted either long or short wavelengths, and the number of unobstructed stars were recorded. Afterwards, a two factor DOE was used to analyze the data from the two populations (light shielding and light wavelength) to find if light pollution could be significantly reduced by using full, downward shielding and long wavelength lights, shielding being the amount of outer covering the light is surrounding by. No shielding, a plate-shaped shield, and a bowl-shaped shield were used along with compact flourescent, incandescent, and high-pressure sodium light bulbs. Although the data did show more visible stars with longer wavelength lights (high pressure sodium), the difference between the populations of high and low wavelength lights was not significant enough to conclude that long light wavelength could reduce light pollution. However, after analyzing the data, light shielding was found to significantly reduce light pollution. Overall, it may be said that if light shielding was used more frequently in urban areas the amount of light pollution could be reduced.

Research Conducted By:

Nathan Bewsick
Fitzgerald High School

Andrew Borders
Cousino High School