10 Accidental Inventions You Won't Believe

The Microwave Oven

Despite its usefulness, you may be surprised to learn that the microwave oven was developed by accident. Without it, what would we use to quickly heat up our leftovers or pop popcorn?

We can thank Percy Spencer for discovering the microwave while inspecting a magnetron, or a type of tube that releases energy to power radar equipment. As a leading scientist during World War II, Spencer was visiting a lab at the Raytheon Company, when he noticed something strange while standing in front of the device.

Believe it or not, the contents of Spencer's pocket got his attention: a candy bar stored there had melted. Spencer, on the other hand, didn't melt (thankfully!). We know today that prolonged exposure to microwaves -- the waves, not the appliances -- can be harmful to humans in certain circumstances.

Looking for another food item to challenge the device with, Spencer decided corn kernels would do the trick. After his success with popcorn and other foods, Spencer invented another machine with similar technology, which gave rise to the microwaves we see today.

Invented in 1945, the microwave is still a popular must-have for more than 90 percent of U.S. households more than 65 years later [source: Liegey].

You may recognize our next accidental invention. Here's a hint: It's known to challenge male impotence.

A Notable Mention: Super Glue Some people also consider Super Glue a household necessity. This unyielding adhesive didn't spring to life from someone's imagination, though. Rather, its inventor came across it twice before realizing its potential. First, while looking to create plastic for guns during World War II, Harry Coover noticed that the substances he worked with -- called cyanoacrylates -- were particularly sticky. It wasn't until he began working with them again in efforts to develop heat-resistant materials that he came back to these compounds, which hold a superior bond with no heat.