Light bulbs are described by the color of the light that they produce. In that regard, a temperature of 1200C would correspond to a red orange. <http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Flowel.tiffen.com%2Fedu%2Fcolor_temperature_and_rendering_demystified.html&ei=Ef5DVKD0MNj_yQT8toGIDg&bvm=bv.77648437,d.aWw&psig=AFQjCNH71xFUDo2GXIveYEduRGMTWwWicA&ust=1413828256200317> <http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fwww.robaid.com%2Fgadgets%2Fdefinite-guide-for-declaration-found-on-light-bulb-packages.htm&ei=lf1DVLSCAsK0yASz-4DwBg&bvm=bv.77648437,d.aWw&psig=AFQjCNH71xFUDo2GXIveYEduRGMTWwWicA&ust=1413828256200317>
On Sun, Oct 19, 2014 at 12:37 PM, Eric Walker <[email protected]> wrote: > On Sun, Oct 19, 2014 at 7:05 AM, Craig Haynie <[email protected]> > wrote: > > "The temperature of a Pāhoehoe <http://en.wikipedia.org/wiki/ >> Lava#P.C4.81hoehoe> lava flow can be estimated by observing its color. >> The result agrees well with measured temperatures of lava flows at about >> 1,000 to 1,200 °C (1,830 to 2,190 °F)." >> >> http://en.wikipedia.org/wiki/File:Pahoehoe_toe.jpg > > > I assume the temperature should be estimated from the light patches in the > lava flow, since the darker patches are areas of the surface that are > starting to harden. The lighter portions match the color in the image Jed > has been pointing to, making an estimate of 1000 to 1200 C seem reasonable > [1]. > > The challenge with lava is that it is essentially a blackbody, as can be > seen by the areas of the lava flow that have already cooled down. People > are debating elsewhere in this thread whether the same heuristic for > deriving temperature from color can be applied to something that isn't a > blackbody (e.g., glass, or an alumina cylinder). I wonder if there is > someone who can speak from professional experience on this question. > > Eric > > > [1] > http://en.wikipedia.org/wiki/Incandescence#mediaviewer/File:Incandescence_Color.jpg >
