Home made spectrometer tells you what rainbows mean

Don't tell the Double-Rainbow guy, but all those beautiful colors really can have a deeper meaning. That's because different chemicals reflect and absorb different wavelengths of light, leaving tell-tale patterns in the rainbow. If you know what colors specific chemicals absorb, you can look at the light reflected off a sample and use the rainbow to figure out what you've got. That's basically what a spectrometer does. And blogger Charles Soeder made his own.

Home made spectrometer tells you what rainbows mean

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