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Comment by sfifs | Hacker News Reader

Very interestingly, this seems similar to the strategy used by plants to absorb energy from sunlight in the red and blue parts of the spectrum with pervoskite absorbing the blue and silicon the green. However there is no indication this is intentional bio mimicry. Do we not have materials which can absorb the middle green part of the spectrum?

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It's not really very interesting. Those parts of the spectrum are where the energy is concentrated. There's quite a bit in infrared, but it's spread out over a wide range of wavelengths, so difficult to use (except as heat).

Assuming this[0] is accurate, it looks like solar irradiance reaching the surface is pretty flat from mid-blue up to red, including green. I would guess either there are other evolutionary reasons for reflecting green, or no reason at all and chlorophyll happened to be the first/easiest substance to evolve for photosynthesis.

[0] https://en.wikipedia.org/wiki/Sunlight#/media/File:Solar_spe...

The most successful aquatic phototrophs, e.g. brown algae and diatoms, absorb a much larger fraction of the solar light, by having complementary pigments that transfer the energy to chlorophyll.

On the other hand, the terrestrial space is dominated by the green plants because here the problem is not absorbing more of the abundant light, but avoiding overheating from absorbing too much light (because the efficiency of photosynthesis is low, so most of the absorbed energy becomes heat, and not only there is much more light in air, but also the cooling is more difficult than in water).

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