|Does blue color absorb heat?|
|Question Date: 2014-04-04|
The colors that your eyes detect are the colors
that are reflected (bounced off) a surface. For
instance, if you're wearing a green shirt, it
really means that your shirt absorbs all the
visible light except green. That's the only way
your eye would be able to detect the green light.
If your green shirt absorbed green, then green
light would never make it to your eye!
The same principles apply to heat! Heat can be
transferred in a couple different ways, but one
way is radiation. All objects radiate heat energy,
even our own bodies. You may be able to guess that
hotter object emit more radiation than colder
objects. Radiation is transmitted by waves, and
these waves can be absorbed or reflected just like
If you stand in front of a camp fire, or a
barbecue grill, you have experienced this: when
you hold your hands out and feel the warmth, you
are absorbing the heat waves coming from the fire.
To answer your question more generally, all
colors absorb and reflect heat, however, different
colors do it better or worse than others.
Typically, lighter colors reflect more heat and
darker colors absorb more heat. If you've even
worn a black shirt on a hot day, you'll notice
this. Another example is how the blacktop pavement
gets really hot sometimes: hot enough to see heat
radiating from the surface!
So, yes: blue does absorb heat. However,
as you know, there are many shades of blue. Darker
blues will absorb more heat (royal blue for
example) and lighter blues will absorb less heat
(baby blue). A general rule of thumb is: the
darker the color, the more heat that color will
absorb. So, on a hot day, make sure to wear
light-colored clothing to stay as cool as
possible! Thanks for the great question!
Good question! If an object is not totally
transparent or reflective, then it is capable of
absorbing energy in the form of light or heat. If
something is blue, that means it absorbs all
frequencies of visible light except blue (450
nanometer wavelength) light which is reflected or
transmitted through. Usually objects which absorb
all this light as energy have no way of converting
that energy except by reducing it to heat in the
form of vibrations which increase its temperature.
Some materials can emit light back, and this is
called fluorescence. Other materials can
potentially generate electricity through charge,
and these materials would make good solar cells.
The color blue does absorb heat. In general, the
more light an object absorbs, the more heat
absorbed since light is energy. Black absorbs the
most heat. A black object absorbs all wavelengths
of light and reflects none. Objects that are
white, on the other hand, reflect all wavelengths
of light and therefore absorb the least heat.
Comparing other colors is difficult, as the color
we see is a complicated mixture of the light that
is reflected back to our eyes (not absorbed). But
in general, the darker the color, the more light
and heat absorbed.
This is an answer already stored on our database:
When an object appears a certain color when
illuminated by white light it means that it is
reflecting light of that color and absorbing all
other colors. For example, a red apple is
reflecting red light and absorbing all other
colors of light. The more light the object
absorbs, the more heat absorbed since light is
energy. If you consider it a color, black absorbs
the most heat. A black object absorbs all
wavelengths of light and reflects none. Objects
that are white, on the other hand, reflect all
wavelengths of light and therefore absorb the
When you look at an object and you see that it has
a color, what you are seeing is the light that
gets reflected off the object and gets detected by
your eyes. This means that every other wavelength
of light in the visible spectrum is absorbed. When
light is absorbed, it can get converted into heat.
Therefore, a blue object will absorb visible
light which is not blue, and convert it into heat.
Additionally, even if you had an object which
appeared white (or another color for that matter),
it may still be absorbing ultraviolet or infrared
light which would then also be converted to heat.
All colors absorb heat. Blue things absorb light
that isn't blue.
The fact that a material appears blue means that
the material is absorbing some colours of light
(likely orange). Because energy is conserved, if
the material is absorbing light, it is likely
being converted into heat. For example, if you did
a careful experiment where you had a bright orange
light and shined it on a piece of blue paper and a
piece of white paper, the white paper reflects
more light, so it absorbs less energy from visible
and near-visible light. Because the white paper
absorbs less energy, you would expect it wouldn't
get as hot as the blue piece of paper.
White light, from the sun or a light bulb, is made
up of electromagnetic waves of every color at
once, including "colors" of light that we can't
see. Objects that appear blue do so because they
reflect blue light but absorb all other colors, so
our eyes only see the blue light remaining. When
a blue object absorbs the energy from non-blue
light, it heats up.
Oftentimes when people talk about heat they are
referring to infrared radiation. Infrared
radiation is just like light of a color that we
can't see, it's a form of electromagnetic
radiation. If we could see infrared light, it
would be the color that comes before red in a
rainbow: infrared, red, orange, yellow, green,
blue, purple. People think of infrared radiation
as heat because hot objects give off more infrared
radiation than visible light. An object needs to
reach several thousand degrees (like the sun) in
order to give off more visible light than
infrared. That's probably why we evolved to see
the colors that we do - because the sun puts out
most of its energy in that part of the
A blue object could absorb or reflect infrared
radiation - it looks blue only in the visible
color spectrum and that doesn't tell us anything
for sure about what it does with infrared light.
But most objects except for shiny metals will
absorb at least some of the infrared radiation
that hits them.
So to summarize, blue objects will usually
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