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As light travels through the atmosphere, hitting those molecules along the way, more and more of the shorter wavelengths are scattered. By the time the light reaches your eye, all the blue and violet has been scattered out, leaving only the longer wavelengths in the sky for you to see. That's why a setting sun turns the sky red, orange, yellow and all shades in between. All of that scattered blue and violet is busy creating a blue daytime sky somewhere else in a different time zone.

This is all happening in a clear sky, with mostly nitrogen and oxygen doing the scattering. If you add other molecules into the mix -- molecules in smog, for instance -- the picture starts to change.

Smog, technically speaking, is not the demon it's made out to be. Smog is simply a combination of the words "smoke" and "fog," and it comes from lots of different sources, some totally natural. It's composed mostly of aerosols, solid or liquid particles suspended in the sky. Volcanic eruptions produce heavy smog when they send tons of volcanic ash into the sky. Forest fires do the same when all of that burning matter billows upward, turning the sky nearly opaque.

These natural causes of smog are negligible in big cities, though. Factory and coal-power exhaust, car exhaust and leaking gas, as well as the byproducts of burning plastics and aerosol spray cans send far more particles into the atmosphere than any natural events do. This smog is a mixture of chlorofluorocarbons (greenhouse gases), hydrocarbons, sulfuric acid and lots of other unpleasant pollutants [source: Health and Energy]. In major cities, smog is this human-made mixture of chemicals.

Here's where the confusion comes in. Whereas volcanic smog and forest-fire smog are composed of fairly uniform aerosols, man-made smog is composed of countless different molecules and different types of matter, and all of these aerosol particles vary in size. Size is the deciding factor in whether aerosols enhance a sunset's colors or hinder them.

When something like a volcanic eruption sends particles into the air, it produces smog that blocks only certain wavelength of light. As sunlight moves through this atmosphere, it encounters nitrogen and oxygen, which scatter the blue end of the spectrum, and volcanic ash, which is larger and scatters a good amount of the longer yellow wavelengths, too. What results is an incredibly red sunset until the ash clears.

But smog from a smoke stack or ­car is composed of particles of so many different sizes, the scattering is nearly indiscriminant. Rayleigh scattering is no longer in effect, since instead of the atmosphere scattering only certain wavelength as sunlight passes through it, it scatters everything. The aerosols in smog are varied, and relatively large, to the point that they can scatter every wavelength of light. The result is a sunset with no colors at all. The sky is simply a hazy, grayish white, with all of the yellow, orange and red having been scattered out before they could reach the eye.

Chances are, if you're seeing an especially colorful sunset in L.A., it's because the smog is low that day, not because it's heavy.

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Why is the sky blue in a funny way?

The sky appears blue because of a phenomenon called Rayleigh scattering, where shorter blue wavelengths of light are scattered by the gases in the atmosphere. This scattering causes blue light to be more prevalent in our field of vision, giving the sky its blue color. It's not a funny process, but rather a scientific explanation for why the sky looks blue to us.


What part of the atmosphere causes daylight to occur?

Daylight occurs due to the scattering of sunlight by gases and particles in Earth's atmosphere. This scattering causes the sky to appear blue and allows sunlight to reach the surface even when the sun is not directly overhead.


What happens when particles and gas molecules in the atmosphere reflect and bend solar rays?

The process of scattering occurs when small particles and gas molecules diffuse part of the incoming solar radiation in random directions without any alteration to the wavelength of the electromagnetic energy. This factor also causes our sky to look blue because this color corresponds to those wavelengths that are best diffused. If scattering did not occur in our atmosphere the daylight sky would be black.


When dust particles and gases in the atmosphere reflect light in all directions this is a process called?

Omnidirectional Radiation. OR Scattering


Why does the sun look red today?

The sun looks red today because of particles in the Earth's atmosphere scattering sunlight, causing shorter blue and green wavelengths to be filtered out and leaving longer red wavelengths to dominate the sky.

Related Questions

What is an example of light scattering?

An example is the short wavelengths of sunlight which are blue are scattered by particles in the atmosphere, making the sky blue.


Why is the atmosphere blue?

The atmosphere appears blue because of a phenomenon called Rayleigh scattering. This occurs when sunlight interacts with the gases and particles in the atmosphere, causing shorter blue wavelengths to scatter more than other colors, making the sky appear blue to our eyes.


True or false scattering explains why the daytime sky looks blue?

True. The scattering of sunlight by particles in the atmosphere, known as Rayleigh scattering, is the main reason why the sky appears blue during the day. Blue light is scattered more than other colors because it travels in shorter, smaller waves.


Does scattering make the sky blue?

Yes, the scattering of sunlight by the gases and particles in the atmosphere is what causes the sky to appear blue. Shorter blue wavelengths are scattered more than other colors, making the sky predominantly blue during the day.


Why is the color it the color the earth is?

The color of the Earth, predominantly seen as blue from space, is due to the reflection of sunlight off the oceans and the scattering of light in the atmosphere. The blue color is a result of the absorption and scattering of sunlight by particles in the Earth's atmosphere.


What are the differences between Rayleigh and Mie scattering in the context of light interaction with particles in the atmosphere?

Rayleigh scattering occurs when light interacts with particles that are much smaller than the wavelength of the light, such as molecules in the atmosphere. This type of scattering is more effective for shorter wavelengths, like blue light, which is why the sky appears blue. Mie scattering, on the other hand, occurs when light interacts with particles that are similar in size to the wavelength of the light, such as dust or water droplets in the atmosphere. Mie scattering is more effective for longer wavelengths, like red light, which is why sunsets appear red. In summary, Rayleigh scattering is more prominent for smaller particles and shorter wavelengths, while Mie scattering is more prominent for larger particles and longer wavelengths.


What is rayleigh scattering?

Rayleigh scattering is the scattering of light by particles in the atmosphere that are much smaller than the wavelength of the light. This scattering is responsible for the blue color of the sky during the day and the red and orange hues of sunrise and sunset. The shorter wavelengths of light, such as blue and violet, are scattered more easily by the particles in the atmosphere, leading to the sky's blue appearance.


Why is the sky blue, and is it because of the ocean?

The sky appears blue because of a phenomenon called Rayleigh scattering, where sunlight is scattered by the gases and particles in the Earth's atmosphere. This scattering causes shorter blue wavelengths of light to be more dominant in the sky. The color of the sky is not directly related to the ocean, although the ocean can reflect the blue color of the sky, giving it a bluish hue.


Why are there colors in blue sky?

The blue color of the sky is due to Rayleigh scattering, where shorter blue wavelengths of sunlight are scattered more than other colors by particles in the Earth's atmosphere, causing the blue light to be more visible. This scattering effect is why the sky appears blue during the day.


What are the differences between Mie scattering and Rayleigh scattering in terms of their effects on light propagation in the atmosphere?

Mie scattering occurs when particles are larger than the wavelength of light, causing light to scatter in all directions equally. This type of scattering is responsible for creating white light and is more prevalent in the lower atmosphere. Rayleigh scattering, on the other hand, occurs when particles are smaller than the wavelength of light, causing shorter wavelengths (blue and violet) to scatter more than longer wavelengths (red and orange). This type of scattering is responsible for the blue color of the sky and is more prevalent in the upper atmosphere.


Why are sunsets red purple blue color's wavelengths?

Sunsets appear red, purple, and blue due to scattering of sunlight by particles and molecules in the atmosphere. When the sun is low on the horizon, its light has to pass through a greater thickness of the atmosphere, scattering shorter wavelengths like blue and green, leaving behind the longer wavelengths like red and purple to dominate the sky.


Why is skey blue?

The blue light is scattered by the air molecules in the atmosphere (referred to as Rayleigh scattering). The blue wavelength is scattered more, because the scattering effect increases with the inverse of the fourth power of the incident wavelength.