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doubleunplussed | 7 months ago

I thought it was mostly that those are the wavelengths output out by the sun.

But I guess it could be both.

discuss

order

davrosthedalek|7 months ago

The sun is very close to a black body radiator, so all wavelength. The atmosphere and water filters a lot.

It is actually quite strange that plants are green -- that's the wavelength the atmosphere lets through particularly well, so would be particular good to be absorbed instead of reflected, for energy production. It seems nature hasn't come up with a good, cheap way to move the absorption into that wavelength.

doubleunplussed|7 months ago

Well, black-body radiation is still peaked around a certain range of wavelengths depending on the temperature, it's not just equal power at all wavelengths.

Light visible to humans is at the peakiest bit of the sun's black body spectrum, see here image here: https://i.sstatic.net/kRUju.png

Green isn't just the wavelength the atmosphere lets through the best, or the wavelength humans are most sensitive to, it's also the peak of the sun's black body spectrum.