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From the Nightspeech Bulletin Board

Keran Parizek

Apr 11 13 12:38 AM

Hail. I hope you and yours are well.

New Scientist: Infrared Chlorophyll Could Boost Solar Cells 

The forest in X's and Naani's journey still probably wouldn't have trees that look like ours. The ground will be considerably warmer than the air; infrared phototropism should pull branches down in most places, or toward fireholes and the like. I'd guess they'd mostly resemble oddly-shaped bushes.

This makes the Night Land's ecology more comprehensible, to my mind, though we still have to assume it has numerous herbivores Hodgson didn't mention.

Stromatolites (where the infrared chlorophyll was discovered) seem as if they'd work well in the Night Land, if we assume they can adapt to land. If X and Naani didn't look closely at them, they'd likely assume they were boulders.


The Master Monstruwacan

Apr 14 13 5:36 AM

:boggle:

I would have said this was impossible. Really.

Thanks for the good wishes. Keep in touch.


Vultur10

Apr 14 13 5:36 AM
"Stromatolites (where the infrared chlorophyll was discovered) seem as if they'd work well in the Night Land, if we assume they can adapt to land. If X and Naani didn't look closely at them, they'd likely assume they were boulders."

Cool.

They would also probably be found in hot springs, the Giant's Sea, etc.

--

On reading the article, it says "the 700 to 800 nanometers region". That's very near infrared, just beyond the red-infrared boundary. So I doubt the volcanoes of the Land of Seas and Volcanoes would put out all that much radiation in this range (some, certainly, since they're emitting visible light too: not sure how much).

Assuming lava radiates as a blackbody (an approximation, not sure how inaccurate) this blackbody radiation calculator gives about 2000 nanometers as the peak emission at hot lava temperatures of about 1200 C.

But this isn't something that can use regular thermal infrared.

On the other hand, I don't see why a chlorophyll or other photosynthetic pigment couldn't evolve to use much longer-wave IR during the Darkening. It would be much lower-energy, and might be limited to cyanobacteria, algae or other microorganisms - either by the energy limitations or because I'm not sure trees and other longer-generation-time plants could evolve it that fast, while microbes have super-short generation times.


Vultur10

May 29 13 7:50 PM

I just realized that conventional (visible light) photosynthesis is going to become useless much earlier in the timeline than I had been assuming.

According to the timeline, the Sun ceased to be visible about 16 million AD, 4 million years after the Redoubt's founding. So I was imagining a fairly 'conventional' ecosystem, if energy-starved, still existing, and the "exotic" life (fire-hole "black smoker" communities, farther IR photosynthesis plants) only beginning to make inroads.

But it occurs to me that, given the way the eye responds to light, the Sun will be perilously weak for photosynthesis even before it really appears dim. According to this (http://en.wikipedia.org/wiki/Daylight) bright sunlight is as much as 300x stronger than the illumination at sunrise/sunset. Yet it certainly doesn't "look" 300 times brighter.

So long before the time the Sun has dropped to, say, the brightness of the full Moon (hundreds of thousands of times dimmer than the Sun) photosynthesis in the visible will be useless. Even though the Sun at this stage will probably be putting out far more infrared than visible, I'm skeptical that even IR photosynthesis from the Sun (as opposed to volcanic sources) will do much.

Of course, this depends how the Sun actually dwindles and dies, given that we can't really base this on real world stellar lifecycles. I tend to assume the Sun is just dimming and cooling/reddening, fairly linearly, but maybe not. "Red Giant's Race" suggests the sun has gotten bigger, though dim and red.