Weather
On a day when the sky is overcast, the sunlight passes through the turbid layer of the clouds, resulting in scattered, diffuse light on the ground. This does not exhibit Tyndall scattering because the cloud droplets are larger than the wavelength of light and scatter all colors approximately equally. On a day when the sky is cloud-free, the sky's color is blue in consequence of light scattering, but this is not termed Tyndall scattering because the scattering particles are the molecules of the air, which are much smaller than the wavelength of the light. When sunlight has a greater distance to travel through the atmosphere (at sunrise and sunset) this effect is greater. The Rayleigh Effect is in combination with the Tyndall effect as microscopic dust particles at lower levels scatter shorter wavelength (blue) light away and allow longer (red) wavelengths to reach the observer. Thus the degree of red in a sunset varies depending on the weather. On occasion, the term Tyndall effect is incorrectly applied to light scattering by macroscopic dust particles in the air. However, this is more like reflection, not scattering, as the macroscopic particles become clearly visible in the process.
Read more about this topic: Tyndall Effect
Famous quotes containing the word weather:
““Why don’t you finally publish your works?” My friend, in bad weather one had better stay home.”
—Franz Grillparzer (1791–1872)
“The average Kentuckian may appear a bit confused in his knowledge of history, but he is firmly certain about current politics. Kentucky cannot claim first place in political importance, but it tops the list in its keen enjoyment of politics for its own sake. It takes the average Kentuckian only a matter of moments to dispose of the weather and personal helath, but he never tires of a political discussion.”
—For the State of Kentucky, U.S. public relief program (1935-1943)
“What
One believes is what matters. Ecstatic identities
Between one’s self and the weather and the things
Of the weather are the belief in one’s element,
The casual reunions, the long-pondered
Surrenders, the repeated sayings that
There is nothing more and that it is enough....”
—Wallace Stevens (1879–1955)