Comment on Blue could have been a warmest color
unknownuserunknownlocation@kbin.earth 4 days ago
Not quite. "Warmer" colors actually heat things up more. There's a reason why heat lamps produce red or infrared light.
Comment on Blue could have been a warmest color
unknownuserunknownlocation@kbin.earth 4 days ago
Not quite. "Warmer" colors actually heat things up more. There's a reason why heat lamps produce red or infrared light.
TranquilTurbulence@lemmy.zip 4 days ago
Hmm… I didn’t think about black body radiation that much. The filaments in a toaster really are red/orange/yellow when hot. I wonder what it would take to to squeeze blue out of black body radiation. Theoretically, it should be possible. Probably thousands of degrees… I think we’re moving into plasma physics territory at this point. Regular filaments just wouldn’t be able to handle blue light production. Electric arcs are blue though, and that plasma is pretty hot.
unknownuserunknownlocation@kbin.earth 4 days ago
I think you're missing the point a bit. I'm talking about how much heat different wavelengths of light transfer.
There's an interesting experiment you can do if you have the right equipment: take the classic experiment where you produce a rainbow with a prism. Then, take a sensitive thermometer and go along the spectrum. The red end of the spectrum will be the warmest (unless you go even further, the area beyond that will be even warmer from the infrared), the blue end the coldest (although still warmer than the surroundings).
TranquilTurbulence@lemmy.zip 4 days ago
Oh ok. So when the peak of the emission spectrum is in the IR range, the visible color will definitely be closer to red or orange. The amount of blue light emitted in that case will be very low. That’s what the thermometer experiment can definitely demonstrate clearly.
However, if the black body is hot enough that the peak is in the blue wavelength band, then the total IR output should also be pretty high, just like everything else is at that point. I wonder if it’s even higher than in the first example. Would need to calculate that properly… Anyway there will also be a fair bit of UV, so don’t try this at home. Maybe even some x-rays if the arc is hot enough.
As far as traditional carbon-arc lamps are concerned, people at the time wrote that the light was white. Maybe the arc was not hot enough or be perceived as blue. Also, the human eye is not particularly sensitive at those wavelengths, so that could explain some of it too.