samim'water is transparent only within a very narrow band of the electromagnetic spectrum,
so living organisms evolved sensitivity to that band, and that's what we now call "visible light". '
🪬🍄🌈🎮💻🚲🥓🎃💀🏴🛻♓🧿@samim oh word, I always thought it was a weird coincidence that it was clear *and* useful for life. That makes much more sense!
So we could infer that life that evolved on, say, Titan, would be able to see wavelengths that penetrate liquid methane.
gkrnours@samim I wonder the thing that feel our eyes have similar propriety and as such would block other wavelength even if we had receptor able to catch them
Aleš Roubíček
simonf 🦘@samim
?
Photoreception and vision in the ultraviolet
@samim
And apparently infrared too
https://a-z-animals.com/animals/lists/animals-that-can-see-infrared/
Licho@samim "how lucky we were that water is transparent in the narrow band that out eyes can see. Truly it must be the work of god!"
Anthropic principle people
I'm still puzzled why this nonsense was in the official curriculum of my highschool. I called out the teacher and she was embarrassed.
Mark Dominus@licho @samim But there seems to be something else going on: water is transparent in the same range of frequencies that are actually emitted by the sun. If the sun were much hotter, most of its radiation would be in the X-ray spectrum and would be blocked by water, leaving the world dark.
So God's kindness was not in making water transparent to visible light, but by making the sun emit light that can pass through water!
Or maybe in adjusting the Planck constant to enable that.
Also, in perfectly situating our ears so that our hats don't fall down over our eyes.
@mjd @samim okay, I decided to not be lazy and respond as if it was a serious thing.
There's plenty of stars. The life developed on a planet that
1. Has water
2. Orbits a sun that delivers it enough energy despite having all that water that would have blocked majority of that energy if it was not in the right window.
Planets that are able to support life are rare but they happen nevertheless, because there are billions upon billions of attempts. The universe is just so big, that the right conditions happen somewhere.
Although it is incredibly unlikely that you will ever win a lottery, someone somewhere does in fact win a lottery quite often.
@licho Also don't forget that God in his infinite and providential wisdom created the uvula so that people would be able to pronounce French correctly.
Mark Dominus (@[email protected])
I did Google search for "function of the uvula" and it had several plausible answers: "when swallowing, the uvula moves upward to block the nasopharynx", "the uvula can trigger the gag reflex", "the uvula contains immune cells". All plausible and worth looking into for confirmation. But it also said "the uvula helps produce certain sounds, such as the French 'r'", which is like saying that the function of the ears is to hold up your eyeglasses.
RyeNCode 🇨🇦
LR
LeiderNein@samim Well, plus the 'minor' fact, that the intensity maximum of the sun spectrum is near the visible range, too (as your lower graph shows)
Peter 🦈@samim
Wahrscheinlich stammen wir alle von Wasserbewohnern ab. Das würde erklären, warum 'rein zufällig' der sichtbare Bereich des Lichtes genau dort liegt.
We probably all descended from aquatic creatures. This would explain why, *purely by chance*, the visible spectrum of light is exactly there.
Wahrscheinlich stammen wir alle von Wasserbewohnern ab. Das würde erklären, warum 'rein zufällig' der sichtbare Bereich des Lichtes genau dort liegt.
We probably all descended from aquatic creatures. This would explain why, *purely by chance*, the visible spectrum of light is exactly there.
Zuthal@samim and by sheer coincidence, water's transmission gap also coincides with the peak spectral radiance of our sun
Andy
Pete Alex Harris🦡🕸️🌲/∞🪐∫@G33KatWork @zuthal @samim
I think it's only dependent on temperature, not directly coming from the fusion, which is happening way down in the core. It takes a while for energy to make its way out of there to the Sun's surface through a lot of hot, dense plasma.
I think it's only dependent on temperature, not directly coming from the fusion, which is happening way down in the core. It takes a while for energy to make its way out of there to the Sun's surface through a lot of hot, dense plasma.
Veronica Olsen@petealexharris @G33KatWork @zuthal @samim Yeah, that's right. It's also related to the temperature on the surface, not in the core where the fusion happens, which requires *a lot* more heat and pressure.
The light spectrum of the sun has absorption lines for the various elements too. It's how we get the red/blueshift of distant stars to determine their relative radial velocity from our point of view.
clew
noodle@samim
A certain type of physics student is going to hate this.
Why is [thing] transparent?
Because water is transparent.
Why is water transparent?
Because evolution.
Dexter
Richard "RichiH" Hartmann@samim residual water in glass fibers is also where the 850 nm for multi mode and 1310 and 1550 nm for single mode are coming from
Androcat@samim And when I tell people that colors are qualia, something the brain adds to the sensory input for utility, they start yammering about photons :)
Seiðr@samim Chance and Necessity 
josh 
@samim this rules
/mərˈkjʊriəl/@samim wait, so if we could see the colours beyond visible light, would water be opaque/translucent???
Ross Burton@writeblankspace @samim If the visible range was moved instead of extended, yes.