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-- (talk) 23:23, 20 January 2015 (UTC)

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Current definition: "a general term for the emission of electromagnetic radiation at a different wavelength than that at which it is absorbed" is taken (slightly changed) from: , but I think it's wrong. I've checked in a few other sources (eg., Britannica), and lumincescence is only light emission (not any EM radiation) and nothing has to be absorbed (eg. in bioluminescence). Wojdyr 20:12, 29 July 2005 (UTC)

- This article should really mention that the mechanism of luminescence requires the release of a photon, which balances the energy of an electron jumping to a lower energy state (as in not a photon released in a nuclear reaction.)

- Get rid of subatomic motions as a source of luminescence, or get rid of everything other than that.

- The article contradicts itself when is contrasts luminescence with incandescence, and yet describes thermoluminescence.

- "Luminescence is light that usually occurs" is like a terrible phrase. —Preceding unsigned comment added by (talk) 23:07, 4 May 2010 (UTC)

I know a bunch of phosphors which are excellent still at temperatures far above 1000°C. Of course temperature quenches optical transitions, but in fact it is also able to enhance luminescence (for example if at lower tempreature a certain barrier can not be passed, see e.g. the charge-transfer excitation in YVO_4:RE, where RE is Eu^3+, Dy^3+ or other trivalent rare earth ions).
Therefore i propose a different definition. Let's for example take Blasse and Grabmayer (Luminescent Materials, Springer 1994):
"A luminescent material ... is a solid which converts certain types of energy into electromagnetic radiation over and above thermal radiation". This simply means it is a conversion of energy into EM radiation by matter, excluding incandescence.-- (talk) 13:24, 7 July 2010 (UTC)

I disagree with poster when he states that the "The article contradicts itself when is contrasts luminescence with incandescence, and yet describes thermoluminescence." This is patently wrong. When one reads the article on thermoluminscence, it clearly explains that the phenomenon is characterized by release of photons in wavelengths not attributable to black body radiation.

I disagree with the proposed definition by poster First, the material doesn't have to be a solid. "Over and above" is not good phrasing, IMO it should be "as distinct from." The statement is confusing as thermal radiation includes those wavelengths in which luminescence is observed, the difference is they are not caused by heat, but by other, distinct mechanisms. The current definition is much better than the to which this poster objects, but I wanted to get my criticisms to his points on record to avoid any future confusion. Brownwn (talk) 22:23, 10 October 2014 (UTC)maddie was here