A chemist's cloudy, 'failed' liquid became the fiber in bulletproof vests

In 1965, DuPont chemist Stephanie Kwolek was hunting for a lightweight fiber to reinforce car tires when a batch of her polymer solution came out thin, cloudy and watery - the opposite of what a usable fiber should look like. Most chemists would have thrown it out, but she convinced a technician to spin it anyway. It formed a fiber five times stronger than steel by weight, ounce for ounce: Kevlar.

— Stephanie Kwolek, Stephanie Kwolek — DuPont, 1965; U.S. Patent 3,819,587