"Chemists use expensive tools called spectrometers (there are several kinds) to analyze unknown solid or liquid samples. We are working on a cheap version which we hope to use to identify oil contamination in water and soil, as well as a range of other possible toxins. Spectrometers can also be used to identify species of plants or crop diseases, assess plumes from smokestacks, and have many other applications."
"What we perceive as a single color consists of multiple blended colors -- just as green paint can be made from mixing yellow and blue paint. A spectrometer is a device that splits light into the various colors it is composed of, which we otherwise cannot distinguish with the naked eye. By viewing a substance through a spectrometer, one can distinguish the exact mixture of colors, which correspond to specific wavelengths of light, that make up the perceived color of the sample."