Public
- Public
- Network
- Groups
- Featured
- Popular
- People

Conversation

Notices

Embed this notice
James Dreben :mw: (jdreben@mastodon.world)'s status on Thursday, 04-May-2023 02:21:39 JST James Dreben :mw:

#ELI5 Why is water see through?
I'd never thought about it like this. Wow.
In conversation Thursday, 04-May-2023 02:21:39 JST from mastodon.world permalink
Attachments
1. My 4 year old asked me and I think it's a rather good question that I would like to answer so she understands. Thanks in ExplainLikelmFive by mrmojorisin444 11.1K Q 164 @ 14h Emyrssentry ↑ー/ * 4 13h It's a little bit backwards. Life needed to be able to see through water, so it created eyes that could see the light that water was clear to. That might need some explanation. All things are "clear" to some kinds of light and "opaque" to other light. Like how an X ray can go right through your skin and see your bones. It's that way for all light, including visible light. So there was always some wavelength of light that made water "clear". And some of those wavelengths are the visible light spectrum. So when life evolved in the ocean, and eyes developed, it was very useful to be able to see the light that could pass through the water. And so you get eyes that can see in the ocean. Edit: so the phrase I'd use for the actual 4 y/o is "It's see-through because eyes were specially made to see through water" or if you want it to sound more awesome but less helpful "because your eyes are like x-ray goggles for water."
  https://s3.eu-central-2.wasabisys.com/mastodonworld/media_attachments/files/110/289/658/684/335/881/original/4fc512a763d8ce97.jpeg
- Embed this notice
  Andrew Abdalian (abdalian@lingo.lol)'s status on Thursday, 04-May-2023 13:37:36 JST Andrew Abdalian
  in reply to
  
  @Jdreben It took me a minute to find the original post, so I thought I'd share the link in case anyone needs it.
  https://www.reddit.com/r/explainlikeimfive/comments/133hbvd/comment/ji9zbcc/?utm_source=reddit&utm_medium=web2x&context=3
  
  In conversation Thursday, 04-May-2023 13:37:36 JST permalink
  
  clacke likes this.
- Embed this notice
  Nicholas Sushkin (nsushkin@hachyderm.io)'s status on Tuesday, 23-May-2023 18:27:42 JST Nicholas Sushkin
  in reply to
  
  @Jdreben hmm, none of the animals developed x-ray vision
  
  In conversation Tuesday, 23-May-2023 18:27:42 JST permalink
  
  clacke likes this.
- Embed this notice
  juul (juul@mastodon.xyz)'s status on Tuesday, 23-May-2023 18:28:24 JST juul
  in reply to
  
  @Jdreben Yes though this might lead someone to think that we can see the entire spectrum where water is transparent. Water is transparent in a wider spectrum than humans can see and there are fish that can see infrared and shrimp that can see pretty far into the UV spectrum (mantis shrimp). There is a good reason why animals don't see into the deep UV tough: It's blocked by the ozone layer. https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water#/media/File:Absorption_spectrum_of_liquid_water.png
  In conversation Tuesday, 23-May-2023 18:28:24 JST permalink
  Attachments
  1. Domain not in remote thumbnail source whitelist: upload.wikimedia.org
    
    Electromagnetic absorption by water
    
    The absorption of electromagnetic radiation by water depends on the state of the water. The absorption in the gas phase occurs in three regions of the spectrum. Rotational transitions are responsible for absorption in the microwave and far-infrared, vibrational transitions in the mid-infrared and near-infrared. Vibrational bands have rotational fine structure. Electronic transitions occur in the vacuum ultraviolet regions. Liquid water has no rotational spectrum but does absorb in the microwave region. Its weak absorption in the visible spectrum results in the pale blue color of water. Overview The water molecule, in the gaseous state, has three types of transition that can give rise to absorption of electromagnetic radiation: Rotational transitions, in which the molecule gains a quantum of rotational energy. Atmospheric water vapour at ambient temperature and pressure gives rise to absorption in the far-infrared region of the spectrum, from about 200 cm−1 (50 μm) to longer wavelengths towards the microwave region. Vibrational transitions in which a...
  clacke likes this.
- Embed this notice
  Walter Tross (waltertross@mastodon.online)'s status on Tuesday, 23-May-2023 18:28:57 JST Walter Tross
  in reply to
  
  @Jdreben I wouldn't say that this is the main reason why we see the wavelengths between infrared and ultraviolet. It's not a coincidence that the peak of the sun's emission lies approximately in the middle of that range!
  
  In conversation Tuesday, 23-May-2023 18:28:57 JST permalink
  
  clacke likes this.

Public

Conversation

Notices

Feeds