By Meghan Holohan. The history of scientific discovery is full of missteps. Sometimes iffy ideas lead to stronger theories. Other times, a good idea becomes a bad idea. And still others seem like they were always bad ideas (if scientists don't understand why something glows in the dark, maybe you shouldn't paint your face with it).

1. Fire-proof Aprons!

The bright idea: In the early 1900s, designers offered the perfect solution for women who hated seeing a dirty ashtray on the kitchen table—asbestos tablecloths. In fact, housewives (and magicians) were delighted to find out that asbestos materials came with a neat cleaning trick: if you set an asbestos tablecloth on fire, stains would come out, and the things would look brand new! No more washing and drying. Of course, with such a novel, fireproof material in their hands, suppliers didn't want to limit asbestos' potential to the kitchen table. So, they expanded to kitchen clothing. "Careless ladies" who leaned against the stove and caught aflame didn't have to worry anymore thanks to asbestos aprons and oven mitts. In fact, a 1936 article from The Monessen Daily Independent reported that the only disadvantage to the aprons was that they felt a little "starchy."

The downer: Although humans had used asbestos since the Greek and Roman empires (and even though physicians back then noticed that exposure to the fibrous material caused lung ailments), the United States didn't start investigating asbestos' negative affects until the 1970s. While it took governments centuries to ban asbestos, lawyers caught on much faster and mesothelioma attorneys have been suing companies ever since.

2. Glow-in-the-dark Paint

The bright idea: In 1889, Marie Currie and husband Pierre discovered radium and coined the term radioactive. And while little was known about the alkaline earth metal, one thing was for sure: it glowed in the dark! Suddenly, the public was captivated by raduim's luminescence. Manufacturers painted airplane dials, instruments, and watch faces with radium, spawning a huge glow-in-the-dark fad. Women began painting their nails with it to impress suitors, for Halloween, people even coated their faces with the stuff to get that oh-so-ghoulish look.

The downer: A dentist in New Jersey noticed that many of his patients, who worked at U.S. Radium, suffered from deteriorating jaws or phossy jaw. Worse still, the Essex County coroner discovered that women from a plant were dying of severe anemia and leukemia. By 1925, he'd collected enough data to prove that radiation was so high in the women's bodies that it was likely the cause of death. As if exposure to the material wasn't bad enough, many of the watch-painting women had been dipping the tip of their paintbrushes in their mouths to make a finer point for painting tiny numbers on watches. Unfortunately, it took physicians a little while to officially link the substance with cancer.

3. An Automatic Flosser

The bright idea: It's tough reaching those back molars with dental floss, and it's even harder to floss them. That's why Oral-B created the Hummingbird flosser, the Cadillac of dental aids. The ergonomically designed, vibrating electric flosser was made to gently massage those hard to reach spots and turn the flossing experience into a dream.

The downer: Oral-B investors had no idea the Hummingbird flosser would make picking padlocks a dream, too. With a few modifications—mainly changing the power source from a AAA battery to a D battery and replacing the floss with a pick—nefarious MacGyvers can create a vibrating pick that will pop open most padlocks. Even those inept at building can follow the step-by-step directions on the Web (not that we're encouraging it!).