Why is the Sky Blue? Understanding Rayleigh Scattering Explained

  • Context: High School 
  • Thread starter Thread starter kambez
  • Start date Start date
  • Tags Tags
    Sky
Click For Summary

Discussion Overview

The discussion centers around the question of why the sky appears blue, focusing on the phenomenon of Rayleigh scattering. It explores the underlying physics and atmospheric interactions that contribute to this visual effect.

Discussion Character

  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant states that the atmosphere scatters blue light more effectively than light of other colors.
  • Another participant references Rayleigh scattering and notes that the scattered blue light is polarized.
  • A different contribution explains that scattering is inversely proportional to the fourth power of wavelength, indicating that blue light is scattered much more than red light due to this relationship.
  • This participant also mentions that Rayleigh scattering serves as a good approximation for light scattering in media with small scattering particles.

Areas of Agreement / Disagreement

Participants generally agree on the role of Rayleigh scattering in explaining why the sky is blue, but there are variations in the details and emphasis of their explanations.

Contextual Notes

The discussion does not resolve the complexities of light scattering or the specific conditions under which Rayleigh scattering applies, leaving some assumptions and dependencies on definitions unaddressed.

kambez
Messages
2
Reaction score
0
Hello everyone!

Can anyone explain why sky is blue?

Thanks.
 
Astronomy news on Phys.org
Because the atmosphere is better at scattering blue light than light of other colors.

- Warren
 
Welcome to PF!

Hello kambez! Welcome to PF! :smile:

It's because scattering is inversely prooprotional to the fourth power of wavelength … see http://en.wikipedia.org/wiki/Rayleigh_scattering#Rayleigh_scattering_from_molecules" …
The strong wavelength dependence of the scattering (~λ−4) means that blue light is scattered much more readily than red light. In the atmosphere, this results in blue wavelengths being scattered to a greater extent than longer (red) wavelengths, and so one sees blue light coming from all regions of the sky. Direct radiation (by definition) is coming directly from the Sun. Rayleigh scattering is a good approximation to the manner in which light scattering occurs within various media for which scattering particles have a small size parameter.
 
Last edited by a moderator:

Similar threads

Undergrad Density fluctuations and the color of the sky
  • · Replies 0 ·
Replies
0
Views
2K
Undergrad Rayleigh scattering -- What is the true reason for the color of the sky?
  • · Replies 57 ·
2
Replies
57
Views
6K
High School Star like object travels in a zigzagging pattern relative to other stars
  • · Replies 49 ·
2
Replies
49
Views
12K
Undergrad Red-orange skies and wildfires
  • · Replies 1 ·
Replies
1
Views
2K
High School Mars Water: The Truth Behind Its Blue Color and Recent Discovery Revealed
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Spectrometer Shows More Blue light on cloudy Day....why?
  • · Replies 4 ·
Replies
4
Views
2K
High School Why certain stars seem to move very little in the sky
  • · Replies 56 ·
2
Replies
56
Views
7K
Undergrad A busy and interesting night sky in Mackinaw City
  • · Replies 1 ·
Replies
1
Views
2K
High School Understanding Rayleigh Scattering and Changing Sky Colors
  • · Replies 3 ·
Replies
3
Views
8K
Undergrad Scattering of Light in Different Media
  • · Replies 15 ·
Replies
15
Views
3K