Why is the sky blue using avogardo's number?

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Discussion Overview

The discussion revolves around the question of why the sky appears blue, specifically in relation to Avogadro's number. Participants explore historical perspectives, scientific explanations, and the role of molecular scattering in this phenomenon.

Discussion Character

  • Exploratory
  • Technical explanation
  • Historical

Main Points Raised

  • One participant requests a detailed explanation involving Avogadro's number and the equations related to the blue color of the sky.
  • Another participant humorously suggests that the sky's color could reflect personal traits, indicating a light-hearted approach to the question.
  • A third participant references historical figures Tyndall and Rayleigh, noting their initial theories about the sky's color being due to dust and water vapor, which were later challenged.
  • It is mentioned that later scientists concluded that the scattering of light by molecules of oxygen and nitrogen is sufficient to explain the blue sky, rather than larger particles.
  • One participant claims that Einstein settled the question in 1911 by calculating the scattering of light from molecules, which aligned with experimental observations and provided a verification of Avogadro's number.
  • The role of electromagnetic fields inducing electric dipole moments in molecules is noted as a mechanism for light scattering.

Areas of Agreement / Disagreement

Participants express varying levels of certainty about the historical context and scientific explanations, with some agreeing on the role of molecular scattering while others provide differing perspectives on initial theories. The discussion remains unresolved regarding the specific connection to Avogadro's number.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about the historical theories and the dependence on definitions of scattering. The connection between Avogadro's number and the scattering phenomenon is not fully explored.

kealakamu
[SOLVED] Why is the sky blue using avogardo's number?

This question was brought up in a physics class, and was never answered for me.

I was wondering if anyone here can tell me, given avogadro's number, why is the sky blue? (including all the messy equations if possible).

I believe Einstein was the first person to figure this one out.

Thanks
from
kealakamu
 
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To reflect the color of your pretty eyes

Nah, honestly, I have no clue.
 
haha that's sweet, but then that'd make the sky brown
 
Tyndall and Rayleigh thought that the blue colour of the sky must be due to small particles of dust and droplets of water vapour in the atmosphere. Even today, people sometimes incorrectly say that this is the case. Later scientists realized that if this were true, there would be more variation of sky colour with humidity or haze conditions than was actually observed, so they supposed correctly that the molecules of oxygen and nitrogen in the air are sufficient to account for the scattering. The case was finally settled by Einstein in 1911, who calculated the detailed formula for the scattering of light from molecules; and this was found to be in agreement with experiment. He was even able to use the calculation as a further verification of Avogadro's number when compared with observation. The molecules are able to scatter light because the electromagnetic field of the light waves induces electric dipole moments in the molecules.
 

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