>From the wikipedia page on Negative Luminescence *((My thoughts are in double brackets))*
http://en.wikipedia.org/wiki/Negative_luminescence Negative luminescence is a physical phenomenon by which an electronic device emits less thermal radiation when an electric current is passed through it than it does in thermal equilibrium (current off). When viewed by a thermal camera, an operating negative luminescent device looks colder than its environment. *((Rossi's Hotcat is also an electronic device, but instead of appearing cool to an infrared camera as described above, maybe it has the capacity to appear cool to the eye but hot to an infrared camera.))* Negative luminescence is most readily observed in semiconductors. Incoming infrared radiation is absorbed in the material by the creation of an electron–hole pair. An electric field is used to remove the electrons and holes from the region before they have a chance to recombine and re-emit thermal radiation. This effect occurs most efficiently in regions of low charge carrier density. Negative luminescence has also been observed in semiconductors in orthogonal electric and magnetic fields. In this case, the junction of a diode is not necessary and the effect can be observed in bulk material. A term that has been applied to this type of negative luminescence is galvanomagnetic luminescence. Negative luminescence might appear to be a violation of Kirchhoff's law of thermal radiation. This is not true, as the law only applies in thermal equilibrium. Another term that has been used to describe negative luminescent devices is "Emissivity switch", as an electric current changes the effective emissivity. Harry
