Comments by "Bo McGillacutty" (@Mrbfgray) on "How Glass is Made | From Mining Silica to Wonders of Glass!" video.

  1. Simply by being very thin. The amount of stretching and compressing is a function of the distance to center of the "rod". A thin fiber acquires tiny stresses (change in shape at material level) to bend a lot on our scale. Under a microscope that fiber would not do a 90deg corner on a scale that's significant to the thickness of the fiber, without breaking.
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  2. Another way to say it--the fiber's "bending tolerance" to thickness ration would be the same across all scales, microscopic to an inch diameter or whatever. A 1" thick rod would have no problem following the circumference of the Earth, doing a loop. (it could make a loop around a modest size town at 1" diameter, without breaking) It's the same thing for a wire rope or cable, each wire does a small amount of bending relative to it's thinness, to follow a sheave (cable wheel) say, a degree of bending to thickness ratio of the entire cable way beyond permanent distortion and damage (yielding) if it were a solid rod.
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