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merrit lim
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why sky is blue in colour??
why sky is blue in colour??
why sky is blue in colour??
Ken G said:It seems to ignore how atoms and small molecules (like nitrogen) Rayleigh scatter.
merrit lim said:why sky is blue in colour??
Ken G said:Now you might think if red and blue light were creating the same amplitude of electron oscillation, they would scatter equally, but that's not the case-- the amount of light emitted by the electron depends on the square of its acceleration, so if you have oscillation at some frequency f, the square of the acceleration scales with f4. That means light at a factor of 2 higher frequency (like very blue light compared to very red light) will actually be emitted 16 times more. This is called "Rayleigh scattering."
klimatos said:Ken G,
I "think" I understand most of what you are saying, although the needle on my "jargon meter" is pinned. However, I am still waiting for a citation.
Ken G said:I don't understand, why would I cite something in support of something I did not say and is not true? What you taught your students is correct-- the blue sky is scattered light, just as I said above. What I said would be confirmed by any basic physics textbook that endeavors to actually explain the root cause of the microphysics of Rayleigh scattering, and not just cite a formula involving indices of refraction (which are derived from the microphysics anyway). Also, the only jargon I invoked is the Larmor formula, which seems pretty essential to the issue.
Ken G said:The term "emission" does get used in different ways, so you are right to want to make it very clear exactly how that term is being used. "Absorb" is even worse-- some people think of scattering as an "absorption-and-emission" process, but others reserve "absorb" for when the photon is destroyed and any new emission is a new process.
The sky appears blue because of a process called Rayleigh scattering. The Earth's atmosphere is composed of gases and particles, which scatter sunlight as it passes through. Blue light has a shorter wavelength and is scattered more easily, making it the most prominent color in the sky.
Yes, the color of the sky can vary depending on different factors such as time of day, location, and weather conditions. For example, the sky may appear more orange or red during sunrise and sunset due to the angle of the sun's rays passing through the atmosphere.
When the sky is overcast with clouds, the sunlight is scattered in all directions, resulting in all colors being mixed together and appearing as a white or gray color. This is known as Mie scattering, which occurs when there are larger particles in the atmosphere, such as water droplets in clouds.
At night, the Earth's atmosphere scatters much less sunlight, making the sky appear darker. Additionally, when the sun is below the horizon, there is no direct sunlight to scatter, resulting in a darker sky.
While the sky is typically blue during the day, it can appear different colors in certain weather conditions. For example, during a thunderstorm, the sky may appear green or yellow due to sunlight reflecting off of large hail or raindrops. And in areas with high pollution levels, the sky may appear a hazy gray or brown color.