From: H Veeder * Other examples of light emitting bodies which do not follow the incandescent temperature rule are phosphorescent and fluorescent bodies.
Yup. And as far back as 1886 it was noticed that alumina, in one form, was phosphorescent. A paper by Crookes (the one of radiometer fame): "On the Crimson Line of Phosphorescent Alumina." 1886. Today with the benefit of 130 years we realize that the alumina tested back then had slight chromium content – think ruby - and today the message is that an aluminum paste– such as applied to Inconel wires embedded in a alumina tube housing – containing trace chromium - can provide overwhelming phosphorescent red coloration… and thus the tube is not in keeping with an incandescent temperature determination. In short –this Levi report is miles away from being a scientific paper. The details of fabrication of the tube are hidden, and the reddish glow does not necessarily mean lower temperature if there is ruby phosphorescence in a paste or coating.
