If you shine an IR laser pointer on a tooth, the tooth lights up, revealing cavities and fillings, perhaps as nonradioactive imaging. The IR laser pointer also lights up cavities in various nonliving materials, perhaps revealing their depths. I recently bought a flashlight with UV & IR LEDs (search shopping.google.com for ). because I was interested in a cheap way to image building problems (UV shows moisture, IR shows heat leaks, but in this case it lights them up.). Certainly it is no replacement for a thermal imager worth thousands of dollars or a tooth x-ray, but might it, in some cases, be "appropriate technology"?
- = - Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus, BioStrategist