How we first discovered infrared (and how you can discover it all over…

Infrared is a whole spectrum of light that we can only see in Predator movies, and special episodes of Cops. How did people first discover this stealthy light? It all started with a bunch of thermometers in the hands of an astronomy genius — and it's an experiment you can reproduce at home. » 7/27/12 7:00am 7/27/12 7:00am