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Why is the sky blue?

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Re: Why is the sky blue?

#71

Post by SAI_Peregrinus »

staplung wrote: post #18

In The Cuckoo's Egg Cliff Stoll recounts an episode from the oral defense of his astrophysics PhD thesis. A bunch of people ask questions but one prof holds back until... """ “I’ve got just one question, Cliff,” he says, carving his way through the Eberhard-Faber. “Why is the sky blue?” My mind is absolutely, profoundly blank. I have no idea. I look out the window at the sky with the primitive, uncomprehending wonder…

It also needs a bit of biology. Our eyes don't have a flat response over frequency, they're more sensitive to blue than violet. Violet gets scattered even more than blue, and the violet light does shift our perception of the color. But it does so less than it would if we had photoreceptors more sensitive to violet, so the resulting perceptual color depends not just on the intensity of the light at different frequencies but also on our particular biology. People with tritanopia (blue-yellow color blindness) don't have blue-sensitive cones (S cones) and thus to them there is no perceived blue. Not to mention the linguistic history of the word "blue" and why English uses "blue" instead of "青" or some other word, the questions around qualia & what it means to perceive color, etc.

Re: Why is the sky blue?

#72

Post by onestay42 »

srean wrote: post #65
munificent wrote: post #41

Really cool article! Tangential: > “Scattering” is the scientific term of art for molecules deflecting photons. Linguistically, it’s used somewhat inconsistently. You’ll hear both “blue light scatters more” (the subject is the light) and “atmospheric molecules scatter blue light more” (the subject is the molecule). In any case, they means the same thing There's nothing ambiguous or inconsistent about this. In English…

I have always wondered about this. The verb for the first person is to 'see'. To a third person you 'show' For the first person there is 'listen' (or 'hear'). Does English not have a corresponding word for the third person ? What about Germanaic or Nordic languages ? Do they have a third person analogue of 'listen' ?

AFAIK listen used to be used therefor[sic] but it has fallen out of use nowadays. From wiktionary:

> Listen the watchman’s cry upon the wall.

Edit: formatting

Re: Why is the sky blue?

#73

Post by srean »

smlavine wrote: post #70
srean wrote: post #65

Earlier quoted context omitted.

I have always wondered about this. The verb for the first person is to 'see'. To a third person you 'show' For the first person there is 'listen' (or 'hear'). Does English not have a corresponding word for the third person ? What about Germanaic or Nordic languages ? Do they have a third person analogue of 'listen' ?

"tell"?

Ah! That's not bad but it's not the same thing. Good nevertheless.

I can 'show' (or point someone to a) a sight that I am not myself creating in anyway. The word I am looking for would mean to 'make you hear' in the same may to show is to make you see.

I showed him the distant tower.

I ??? him the faint sound.

Re: Why is the sky blue?

#74

Post by jstummbillig »

staplung wrote: post #18

In The Cuckoo's Egg Cliff Stoll recounts an episode from the oral defense of his astrophysics PhD thesis. A bunch of people ask questions but one prof holds back until... """ “I’ve got just one question, Cliff,” he says, carving his way through the Eberhard-Faber. “Why is the sky blue?” My mind is absolutely, profoundly blank. I have no idea. I look out the window at the sky with the primitive, uncomprehending wonder…

I am positively excited about the upcoming first generation of humans who will have all their questions answered, correctly and in the way they can best understand, and as often and many of them as they want – and what that is going to enable.

Re: Why is the sky blue?

#75

Post by srean »

onestay42 wrote: post #72
srean wrote: post #65

Earlier quoted context omitted.

I have always wondered about this. The verb for the first person is to 'see'. To a third person you 'show' For the first person there is 'listen' (or 'hear'). Does English not have a corresponding word for the third person ? What about Germanaic or Nordic languages ? Do they have a third person analogue of 'listen' ?

AFAIK listen used to be used therefor[sic] but it has fallen out of use nowadays. From wiktionary: > Listen the watchman’s cry upon the wall. Edit: formatting

'Hear the watchman’s cry upon the wall' works the same way, no ?

I have clarified what I am looking for in a cousin comment.

Re: Why is the sky blue?

#76

Post by brabel »

jstummbillig wrote: post #74
staplung wrote: post #18

In The Cuckoo's Egg Cliff Stoll recounts an episode from the oral defense of his astrophysics PhD thesis. A bunch of people ask questions but one prof holds back until... """ “I’ve got just one question, Cliff,” he says, carving his way through the Eberhard-Faber. “Why is the sky blue?” My mind is absolutely, profoundly blank. I have no idea. I look out the window at the sky with the primitive, uncomprehending wonder…

I am positively excited about the upcoming first generation of humans who will have all their questions answered, correctly and in the way they can best understand, and as often and many of them as they want – and what that is going to enable.

The same anticipation of great things happening preceded the arrival of widely available internet, but all we really got was cat videos initially, and doomscrolling more recently. I don’t have much hope for great things anymore.

Re: Why is the sky blue?

#77

Post by yawpitch »

The sky isn’t blue. It’s transparent. That’s why you can see stars that aren’t blue at night. When struck by sunlight at the right angles it appears blue, but saying it is blue is like saying the ocean is green when a bucket of it clearly isn’t.

Re: Why is the sky blue?

#78

Post by SAI_Peregrinus »

leeoniya wrote: post #64
ecshafer wrote: post #49

Earlier quoted context omitted.

"Could you be more specific" is a great question to find out more what the person knows and how they thing. You give an answer that, just due to the nature of knowledge and the limitation of language, has some black boxes. And "could you be more specific" is basically asking to go through the black boxes. Its like asking how does Java work or something like that? You can go from "The JVM interprets java byte code" to…

i used something like this in unstructured technical interviews all the time. "you type a phrase into google search, you press enter, get some results. tell me, in technical detail, what happened in that chain of actions" the diversity of replies is fascinating, you learn a lot about a "full stack" candidate this way. Feynman's classic "Why?" chain: https://www.youtube.com/watch?v=36GT2zI8lVA

I'd probably spend at least 20 minutes just to get through how the keyboard works, much more if it's a USB-HID device.

Re: Why is the sky blue?

#79

Post by awesomelybad »

Implementing an atmospheric shader in three.js is a fun way get an understanding of the interaction of the different scattering components, light, and observer’s position. Plus you get a pretty cool effect to play around with after you’re done.
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