Is the Speed of Light Affected by Atmospheric Conditions?

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Photons travel at the speed of light (c) in a vacuum, but their effective speed in the Earth's atmosphere is influenced by the index of refraction. The average speed of light in air, at standard temperature and pressure, is approximately c/1.00029, which is lower than c due to interactions with atmospheric molecules. While photons are constantly emitted and reabsorbed, the concept of friction does not apply to light transmission. Higher altitudes see an index of refraction closer to 1, resulting in speeds approaching c. Understanding these factors is crucial for accurately measuring light's behavior in the atmosphere.
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Do photons travel at the speed of light (c) inside the Earth's atomphere? Or is friction a factor of their velocity.

Ty
 
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Photons are constantly being emitted and reabsorbed by interactions with the molecules in the Earth's atmosphere. Do you want the speed of the photons themselves (which is always c, but because of quantum effects is problematical to measure), or the average speed at which energy is transferred through the Earth's atmosphere (which is easy to measure, and directly related to effects such as diffraction, but is lower than 'c')?
 
Ty, I would like to know the average speed at which energy is transferred through the Earth's atmosphere thnx
 
At standard temperature and pressure, the index of refraction of air is 1.00029 for light in the middle of the visible spectrum. That means that its speed is c/1.00029. Higher in the atmosphere the index of refraction will be even closer to 1. Friction is not a word associated with the transmission of light, as far as I know.
 

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