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p3t3r1
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Sorry, kind of stupid question, but just wondering. Thanks.
It depends on which distribution you are considering: if you consider the distribution in wavelenght, the maximum corresponds to ~ 502 nm (green), but if you consider the distribution in frequency, the maximum corresponds to ~ 884 nm which is in the infrared.NoTime said:The sun closely resembles a blackbody in its emission spectrum with the peak emission in the yellow green area.
Oh my. It's been forever that I've looked at something like that.lightarrow said:It depends on which distribution you are considering: if you consider the distribution in wavelenght, the maximum corresponds to ~ 502 nm (green), but if you consider the distribution in frequency, the maximum corresponds to ~ 884 nm which is in the infrared.
I took 5778 K as sun's surface temperature (wikipedia).
The topic was also discussed here:
https://www.physicsforums.com/showthread.php?t=132258
So what are you saying? It just heats up our insides? Obviously not much gets through us or our shadow would be kind of hard to see. I would think how well our skin reflects light would be more important then how well it transmits light in terms of how hot it makes us feel. Moreover, if the skin was really good at transmitting light then wouldn't we be able to see through it?Jakell said:Similarly, our skin is fairly transparent to visible light, and it takes a good deal of it to heat up our skin.
Integrating in dv (first case) or dl (second case) you have total energy density in both ways; this only is the meaningful physical concept.NoTime said:Oh my. It's been forever that I've looked at something like that.
However, since wavelength is just 1/f then at a crude level this is just wrong.
The distinction is that peak in your formulas represent two different things.
Someone will have to correct me if I'm wrong, but in one case I think you end up with max photon count while the other is total momentum.
Edit: the latter being the normal way of looking at this (green).
russ_watters said:Though hopefully you can figure it out from the responses, no one directly addressed the question asked in the OP. The question is wrong: infrared doesn't feel hotter than an equivalent amount (# of photons) of visible radiation.
lightarrow said:Integrating in dv (first case) or dl (second case) you have total energy density in both ways; this only is the meaningful physical concept.
russ_watters said:Though hopefully you can figure it out from the responses, no one directly addressed the question asked in the OP. The question is wrong: infrared doesn't feel hotter than an equivalent amount (# of photons) of visible radiation.
This isn't about any specific way a ray of light happens to come to be. All I said is that if the number of photons is equal, the one with the higher frequency has more energy. These photons can come from a radio tower, lasers, reflection, filtration, or, yes, black body radiation. But this is not just about black body radiation.uart said:Actually it dedends on how close to "black" your body is at different wavelengths.
russ_watters said:This isn't about any specific way a ray of light happens to come to be. All I said is that if the number of photons is equal, the one with the higher frequency has more energy. These photons can come from a radio tower, lasers, reflection, filtration, or, yes, black body radiation. But this is not just about black body radiation.
.Actually it dedends on how close to "black" your body is at different wavelengths. My skin looks fairly pale at visible light so presumably it relects some part of the visible light falling upon it.
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