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  • samimsamim@mastodon.social
    Jul 22, 2025, 10:36 AM

    '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". '

    Image attached toot
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  • Licholicho@kolektiva.social
    Jul 22, 2025, 6:01 PM

    @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.

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  • Mark Dominusmjd@mathstodon.xyz
    Jul 22, 2025, 7:30 PM

    @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.

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  • Licholicho@kolektiva.social
    Jul 22, 2025, 10:00 PM

    @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.

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  • 🆘Bill Cole 🇺🇦grumpybozo@toad.social
    Oct 2, 2026, 7:55 PM

    @mjd @licho @samim “God” must have sloppy aim.

    The Sun is much more powerful in UV than would be safe for Earth-style life if life itself had not stumbled upon the creation of excess oxygen and hence ozone as a way to shield it.

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  • Lord Caramac the Clueless, KSCLordCaramac@discordian.social
    Oct 2, 2026, 11:26 PM

    @grumpybozo @mjd @licho @samim Aquatic life was thriving before that since UV can't penetrate water very deeply. In the beginning, the production of oxygen by those nasty photosynthetic cyanobacteria was a huge global ecological catastrophe, since oxygen is a deadly poison to many bacteria. But then, life evolved to take advantage of all the oxygen, and soon organisms began to multiply that couldn't even live without.

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  • Peter 🌈🦈33dBm@lazysocial.de
    Jul 22, 2025, 7:06 PM

    @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.

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  • PHASEONE[NeussWave414]NeussWave@neuss.social
    Oct 10, 2026, 9:59 PM

    @33dBm @samim well, akshully... current narrative is that first DNA molecules evolved in water, fused by lightning.
    human eyes can just see visible light up - uh - down to 200m deep, sensors can measure some light down to 1000 m under water.

    but keep in mind there are creatures way deeper than that and even on land there are organisms which prefer the night, UV or don't need light, like some mosses are already happy with a single photon every now and then and shrooms don't need any light at all

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  • Zuthalzuthal@floofy.tech
    Jul 22, 2025, 7:34 PM

    @samim and by sheer coincidence, water's transmission gap also coincides with the peak spectral radiance of our sun

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  • AndyG33KatWork@infosec.exchange
    Jul 22, 2025, 11:02 PM

    @zuthal @samim Serious question: Has this something to do with the fact that hydrogen (aka the stuff water consists of) is fused into helium in the sun?

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  • Veronica Olsenveronica@mastodon.online
    Jul 23, 2025, 4:18 PM

    @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.

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  • kosurekosure@mas.to
    Oct 2, 2026, 6:29 PM

    @samim AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH this is so cool!

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  • Inspiredinspired@hachyderm.io
    Oct 2, 2026, 8:38 PM

    @donburi @kosure @samim It is an interesting direction but I doubt that we would consider sensitivity to these spectra to be "vision". The wavelength is so long (around 1m or more) that I think you would only perceive an intensity and a direction, no resolving power. Also, does the sun emit much VHF? I think solar radiation at relatively high intensities plus transmission through water are both required to make the visible spectrum useful. It would be a cool sense to have and I wonder if some animals do have it.

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