James Dreben Apr 30, 2023

#ELI5 Why is water see through?

I'd never thought about it like this. Wow.

Show threadVictor GijsbersApr 30, 2023

@Jdreben "This must be wrong," I thought, "surely other parts of the spectrum also pass through water." But no, it's exactly right.

(Well, you could nitpick and point out that not all substances would have allowed eyes to evolve that could see through it as well as we can see through water. But that's nitpicking.)

Show threadJasper 🍉

@victorgijsbers @Jdreben i think it's an deceptively easily answer. Not noticing that many substances are basically opaque to everything biological eyes could see, points that direction.

It also ignores that we evolved on land too, over 300 million years, air has a much wider range of transparant frequences, it does not explain why the frequences we see did not drift since leaving the water.

Also there is a question of why these absorption spectra are what they are in the first place.

May 3, 2023 at 8:41pmWeb
Show threadVictor GijsbersMay 4, 2023
@jasper @Jdreben Sure, it's a partial explanation, not a full one. But we hardly ever give full explanations of anything, especially in an everyday context, and the explanation given here highlights a surprising aspect of the situation. So I don't want to be too harsh. 🙂
Show threadAccordionBruceMay 20, 2023
@jasper @victorgijsbers @Jdreben
No worries, there is no answer that won’t inspire a four year old to ask a follow-up