Answer 1:
The answer is yes, color matters, but only for
a specific definition of "color" which you might
not expect. Visible light is just a particular
spectrum of wavelengths in the electromagnetic
spectrum that our eyes have evolved to be able
to see. "Color" describes which of these visible
wavelengths are absorbed or reflected.
When we talk about "heat" that can be reflected
or absorbed we are usually referring to
electromagnetic radiation in the infrared
spectrum, because hot object give off
electromagnetic radiation mostly in the infrared
spectrum*. So the "color" of an object will
affect how much infrared light is absorbed, but
the color that matters isn't the color that we can
see, but the "color" in the infrared spectrum.
Some objects will appear white if viewed under
infrared light with an infrared camera, because
they reflect most heat. Other objects will appear
black because they absorb most of the heat and
don't reflect it to the camera.
The short answer is that color matters, but
it's the color in the infrared spectrum which
controls how much heat will be reflected by an
object.
*The radiation given off depends on the
temperature. Objects up to around 500 degrees
Fahrenheit, like the hot walls on the inside of
an oven, or a pan on a stove, will not give off
any visible light, but they will give off a lot of
infrared radiation. Around 900 degrees F you will
start to see a red glow. Extremely hot objects
like the sun, around 10,000 degrees F will give
off most of their radiation as visible light. The
physics and math describing this are known as
"black body radiation".
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