Tagged Questions
2
votes
2answers
28 views
Penetration of light in the atmosphere
While I was considering an answer to this question, I wondered how much light that enters the atmosphere reaches the ground without colliding with air molecules—if any. I've taken a good bit of ...
4
votes
2answers
55 views
Attenuation mass-thickness for sunset light
We are able to look directly at the sun near sunset and sunrise, which clearly demonstrates the fact that our atmosphere attenuates visible light. Let's imagine it follows the typical attenuation ...
5
votes
1answer
263 views
Why does the sun “shine brighter” some days?
Today, the sun seems extremely bright; more dazzling than usual, and even the roads seem to be brighter so it's not just when you look up in the sky. Is more light actually getting through (perhaps ...
20
votes
2answers
2k views
Why is the sky not purple?
I realise the question of why this sky is blue is considered reasonably often here, one way or another. You can take that knowledge as given. What I'm wondering is, given that the spectrum of ...
2
votes
2answers
945 views
If blue light has a higher energy than red light, why does it scatter more?
As $E=hf=\frac{hc}{\lambda}$, blue light - with a smaller wavelength - should have a higher energy. However, it is the case that blue light scatters the most. Why is it that higher energy rays scatter ...
7
votes
2answers
472 views
What determines the apparent radius of the rainbow?
Let's say I know how to compute the apparent radius of a rainbow from the viewpoint of the observer: take a photo of the scene, measure the distance to a known reference object, and its dimensions. ...
6
votes
1answer
30 views
Refraction and scattered light for NLCs
For helping with judging NLC candidates (are they NLC or not) I have a set of formulas to calculate the minimum altitude (in km) of the candidate given an observed altitude (in degrees) of the ...
