An interesting question, and the answer might
surprise you! Colors themselves do not reflect
or absorb heat. Rather, color is a consequence
of a much more general phenomenon involving
reflection or absorption. To see what I
mean, there are two main ideas I'd like to convey:
1) thinking more generally about electromagnetic
radiation and separating that from the notion of
heat, and 2) the electronic structure of atoms.
The Electromagnetic Spectrum:
Your description of materials interacting with
heat is part of a larger type of interactions
involving light and matter. Light, also known
as electromagnetic radiation, exists as a
whole spectrum of energies, known as the
electromagnetic spectrum .
You might be familiar with a types of
electromagnetic spectrum, such as microwaves or
x-rays. These are in fact all light that differ by
how energetic it is. A tiny sliver of the
electromagnetic spectrum is the visible spectrum,
which is the range of energies (equivalent to
thinking in terms of wavelength or frequency) that
humans are able to see (i.e., as color). Just
below the visible range is the infrared range. If
you were hit by infrared waves, you would feel
that as heat. However, heat itself is not a
form of light but a form of energy. The
infrared waves would excite molecules in your body
that would dissipate that electromagnetic energy
into thermal energy (i.e., heat).
In learning about the electromagnetic spectrum,
we can say that colors and heat are two different
things along the same electromagnetic spectrum, so
one doesn't lead the other. The question is how
is the electromagnetic spectrum related to
absorption and reflection?
Interactions between light and matter:
This questions now delves into how light can
interact with matter. Matter is composed of
tiny components called atoms. Atoms are
composed of even smaller components called
electrons, protons, and neutrons. If you ever
study particle physics, it turns out you can
decompose those further into other subatomic
particles. You'll learn (if you haven't already)
that the nucleus is composed of protons and
neutrons, and the number of protons is linked with
the elemental identity of that atom (e.g., if it
is phosphorus versus hydrogen). Around this
nucleus is a cloud of electrons; something like
(not exactly, but it gets the point).
Figuring out that the structure of the atom was
no small task, and has an interesting
if you're interested. We're going to be mostly
worried about the electrons: Reflection and
absorption are a consequence of light interacting
with the electrons of a material.
We've already mentioned one interaction of
light with matter- heat dissipation through the
vibrations of atoms (specifically, the nuclei) in
matter- but delves into a different story for
It turns out that electrons occupy specific
energies around the nucleus; this is a consequence
of quantum mechanics. Because of this fact,
only certain energies can excite the electron from
a lower energy level to a higher energy level.
That is, only certain energies (i.e., frequencies,
wavelengths) of light can lead to the electron
absorbing that energy. Other energies will pass
through, i.e., be transmitted. The combination of
frequencies of light that is absorbed or
transmitted results in color if the wavelengths of
light lay within the visible range of the
electromagnetic spectrum. Reflection is slightly
different but still involves electrons.
Hope this helps!
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