Solar Energy and Color
Date: Around 1993
Why is it that dark colors absorb more solar energy than light
colors? That means that dark areas of the earth are warmer in sunny weather.
Is this because less light is reflected? Would dark blue be a cooler color
than dark purple or red?
Basically, darker colors are dark because they absorb more of the
light that hits them. In general, light striking a non-shiny object is either
scattered diffusely, transmitted through the material, or absorbed. When we
look at the object we are seeing the diffusely scattered light, and (assuming
the object is opaque enough so that not much gets transmitted) the colors we
see are all those in the original light source that did not get absorbed. A
dark object absorbs most of the light that hits it, so almost no light is
scattered back to give it color.
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Update: June 2012