Seeing in the dark
Tuesday, October 29, 2013 - 14:01
in Physics & Chemistry
Thermal infrared (IR) energy is emitted from all things that have a temperature greater than absolute zero. Human eyes, primarily sensitive to shorter wavelength visible light, are unable to detect or differentiate between the longer-wavelength thermal IR "signatures" given off both by living beings and inanimate objects. While mechanical detection of IR radiation has been possible since Samuel Pierpont Langley invented the bolometer in 1880, devices that also can recognize and identify an IR source after detection have been more challenging to develop.