Why Don’t Sheep Shrink In The Rain?
We appreciate your support on https://www.patreon.com/MinuteEarth Getting wet isn't REALLY what makes wool shrink; it merely exacerbates the friction between the wool fibers, which is stronger...
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If you put a wool sweater through the laundry, it shrinks. So why don’t sheep, which are, you know, basically made of wool, why don’t they shrink in the rain? The answer comes down to friction. Like all mammal hair, wool fibers are covered in overlapping scales that run the length of each fiber. These scales make it easier for the fiber to slide in one direction than the other, which is why, if you grab a strand of your hair and pull it through your fingers, you'll find it moves more smoothly going toward the tip than toward the root end. When a wool - or human hair - sweater gets thrown into the washing machine and tossed around, this one-way resistance becomes a problem, because, as each fiber rubs against its neighbors, its scales act like li...
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If you put a wool sweater through the laundry, it shrinks. So why don’t sheep, which are, you know, basically made of wool, why don’t they shrink in the rain? The answer comes down to friction. Like all mammal hair, wool fibers are covered in overlapping scales that run the length of each fiber. These scales make it easier for the fiber to slide in one direction than the other, which is why, if you grab a strand of your hair and pull it through your fingers, you'll find it moves more smoothly going toward the tip than toward the root end. When a wool - or human hair - sweater gets thrown into the washing machine and tossed around, this one-way resistance becomes a problem, because, as each fiber rubs against its neighbors, its scales act like li...
