[HN Gopher] Why are plants green? To reduce the noise in photosy...
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Why are plants green? To reduce the noise in photosynthesis
Author : dnetesn
Score : 53 points
Date : 2022-10-01 19:27 UTC (3 hours ago)
(HTM) web link (worldsensorium.com)
(TXT) w3m dump (worldsensorium.com)
| Yaa101 wrote:
| Interesting, apart from more efficient solar panels it could hand
| us a solution to better protect our skins with colored sunblock.
| delecti wrote:
| I'm not sure the same consideration applies to sunblock. The
| article makes the case that plants always "want" to let through
| the same quantity of light, but not necessarily the same
| proportion, while we ideally want to block 100% of UV all the
| time.
| greenthrow wrote:
| Solar panels are already much, much more efficient than
| photosynthesis.
| _alxk wrote:
| That doesn't preclude that further optimisation of solar
| panels could stem from research on photosynthesis.
| akira2501 wrote:
| Perhaps.. but part of the reason plants "lack efficiency"
| compared to our solid state electronics is that they need
| respiration to exchange input and output products with the
| environment and the entire plant needs to be laid out in
| such a way that it can maintain a root structure while
| being advantaged with respect to competing vegetation.
|
| The two problem spaces are similar in that they use light,
| but exceptionally different in almost every other respect.
| dvh wrote:
| Because sun is green.
| VierScar wrote:
| Sun white
| kzrdude wrote:
| After passing through the atmosphere, the sunlight is
| strongest in the green (of the visible spectrum).
| [deleted]
| wyager wrote:
| The sun barely looks different from an artificial blackbody
| of the same temperature. The atmosphere is not a big
| consideration here.
| cdumler wrote:
| The sun is classed as a green star[1]. As a black-body
| object, it emits the most light in the green spectrum. We see
| white because we evolved to distinguish color based on our
| star; however, our ability to detect variance in brightness
| in colors is far more limited.
|
| We, in fact, use this to our advantage. View screens transmit
| exactly brightness in narrow red, green, and blue such to
| fool our eyes into believing we see colors there that are not
| in fact there, such as red and green light to simulate yellow
| light.
|
| [1] https://en.wikipedia.org/wiki/Green_star_(astronomy)
| thehappypm wrote:
| But chlorophyll doesn't absorb green, it absorbs other
| colors !
| leeoniya wrote:
| the explanation is actually quite difficult to google.
|
| "why are plants green?" -> because chlorophyl
|
| "why is chlorophyl green?" -> because it reflects green and
| absorbs everything else
|
| okay, you have to search:
|
| "why did plants/chlorophyl evolve to be green"
| marginalia_nu wrote:
| This is tangentially related: https://youtu.be/36GT2zI8lVA
| Silverback_VII wrote:
| I always thought that it's because that they are descendants of a
| bacterium that was forced to use the less profitable part of the
| light spectrum(blue & red) because the main part was already
| occupied by other bacteria. By reflecting green from the sun,
| they reflect the strongest wavelength.
| kzrdude wrote:
| So, are there multiple competing explanations being offered for
| this in general, and none of them have ever become entirely
| settled?
| kingkawn wrote:
| Welcome to true science
| fluoridation wrote:
| The peak of the solar spectrum seems to be in the blueish zone,
| though.
| acdanger wrote:
| I read - I think here[0] - that green light doesn't penetrate
| water as well as other wavelengths. So there was no advantage to
| evolving to absorb the full spectrum.
|
| [0]
| https://press.uchicago.edu/ucp/books/book/chicago/H/bo164656...
| aaaaaaaaaaab wrote:
| This doesn't explain why terrestrial plants didn't evolve some
| way to utilize e.g. UV radiation. It should be possible in
| theory, since we know of radiotrophic fungi:
| https://en.wikipedia.org/wiki/Radiotrophic_fungus
| layer8 wrote:
| The UV frequency range has much less energy in the solar
| spectrum than visible light, see here:
| https://sunwindsolar.com/solar-radiation-spectrum/
| moffkalast wrote:
| > there was no advantage
|
| Well there is one disadvantage even: overheating.
| leobg wrote:
| I still don't understand. How does specializing on blue and red
| remove the noise from flickering sunlight? After all, when it
| flickers (say, because of shades or clouds), doesn't that affect
| all wavelengths equally? Why should green light be more unstable
| in that regard than blue and red?
| layer8 wrote:
| I didn't quite get that either. It seems to be based on the
| fact that the intensity of sunlight varies with frequency:
| https://sunwindsolar.com/wp-
| content/uploads/2013/09/insolati.... Green in the middle of the
| visible spectrum is the most intense, whereas blue and red fall
| of towards the edges of the visible spectrum, so are less
| intense. Maybe the noise is less for blue and red merely by
| virtue of those frequency ranges having less intensity.
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