After 5 years of seeing media shots of Arabs/Desert Dwellers, why do they wear layered robes and head gear and why are they dark colored?
Is there some sort of evaporative cooling to be found wearing all of those clothes, or are they more designed to act as insulation from the Sun, keeping their bodies temperature constant?
Clothing
To avoid the heat, people in deserts have to dress up carefully :
The long, flowing robes shield the skin from the sun and allow air to reach the body. The clothes are loose-fitting to prevent immediate sweat evaporation so that the body does not dehydrate so quickly in the very dry air. Headgear shields the head from the sun. Veils protect the face and keep the sand out of the mouth. The clothes also keep the people warm at night and in winter
Color
In the desert, wear white clothing. White reflects heat. Even the Turags, a desert people famous for their blue-black clothing, wear white outer garments occasionally. Next, cover your entire body. The reason desert people completely clothe themselves, even in the heat of the day, is because it slows the rate that sweat leaves the body. In other words, ration sweat, not how much you drink.
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General Science Archive
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Black Clothing in the Desert
2002042
name Jon
status student
age 16
Question - hello,
We all know that white reflects heat while black absorbs most heat. In
the desert wearing a black robe would absorb more heat than a white one
(naturally), and wearing a black robe could increase temperatures inside
by about 6 degrees. Why do people wear black robes in the desert?
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Some assumptions need validation:
1. Who says few/some/most/all people in the desert wear black robes -- or
have we been taking "Lawrence of Arabia" too seriously?
2. "Black" and "White" apply to the absorption / reflection of visible
light. It says nothing about the absorption / reflection of infrared, which
might be a more important factor.
3. It is assumed that the "black" and "white" fabric are the same type
material woven in the same way, etc. This point may not be correct. A black
loosely knit fabric may well be "cooler" than a tightly knit white fabric.
It would allow the fabric to "breathe" better.
4. Other issues than the coolest garment may be important. For example: Are
there religious or cultural reasons for wearing one color vs. another? If we
believe the newspaper and magazine photos, it would appear that most people
in the desert wear turbans rather than loose fitting headgear. Certainly
this practice is not consistent with keeping cool since most body heat is
lost from the head.
5. If the color of the dress is important, then certainly the color of the
skin is equally or more so. However -- although this is a generalization --
people living in hot climates tend to be dark skinned, and people who live
in cold climates tend to be light skinned.
This does not make sense, does it?
Need more data before any conclusions can be made about this inquiry.
Vince Calder
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I am going to guess...These things are usually not just for one reason.
First off some wear white , some wear black...even in the same tribe. Here
are some factors that will come into play:
Availability of color fabrics
Cost
Personal preference
Custom
Thickness of the fabric...layers
I recently saw a special on desert nomads of the African desert and some
wore white while other wore black. Also, I am not at all sure I would
accept the 6 degree estimate...It seems possible that the color will matter
much less in the multiple air layer that the robes assume. The outermost
layer would certainly absorb more heat but then it would have to be
conducted to through the inner layer(s). Here is a scenario. I wear a thin
tee shirt on a sunny day..if it is black I notice the difference form white.
If I then wear a tee shirt and a black shirt over it...it makes less of a
difference.
Peter Faletra Ph.D.
Assistant Director
Science Education
Office of Science
Department of Energy
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