|MadSci Network: Physics|
Hello, Eric! There is a lot of information about lightning at the site lightning [Note that this site has a religious component; I believe that the science is sound] In particular, it gives the temperature of lightning as 27,600C - the thermal emission from air (or anything!) heated to that temperature would indeed be a bluish white. You may also get some emission lines from ionized atoms; it would be interesting to look at the spark with a diffraction grating. This would tell you whether you have a continuous spectrum, or emission lines combining to appear continuous to your eye. There is a lightning Webring at more lightning You can find a lot of other information here. Measurements have been done of the spectrum of lightning near the earth; lines coming from vaporized material from the ground are seen. Check out: flash
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