7 Everyday Inventions That Were Created by Accident

Some of the most useful things we rely on today—like microwaves and penicillin—only exist because someone messed up.

Sophia Zapanta
March 17, 2025
3 min read

7 Everyday Inventions That Were Created by Accident — Nikolai Ulltang on Pexels

Not all inventions came from genius planning—some happened because of lucky accidents. From a scientist’s moldy petri dish to a frustrated engineer’s melted chocolate bar, many everyday products were born out of mistakes. Here are seven inventions that prove a little chaos can lead to something great.

1. Penicillin

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In 1928, Alexander Fleming left a messy lab before going on vacation, only to return and find mold killing bacteria in his petri dishes. Instead of tossing it out, he studied the mold and realized it had powerful bacteria-fighting properties. This accident led to the creation of penicillin, the first widely used antibiotic. Without his untidy habits, modern medicine might look very different today.

2. Microwave Oven

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In the 1940s, engineer Percy Spencer was working on radar technology when he noticed the chocolate bar in his pocket had melted. Curious, he experimented by placing popcorn kernels near the equipment, and they popped instantly. He realized the microwaves from the device could cook food quickly. Soon after, the first microwave oven was born, changing kitchens forever.

3. Post-it Notes

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A scientist at 3M, Spencer Silver, was trying to create a super-strong adhesive but accidentally made one that barely stuck. His invention seemed useless until a colleague, Art Fry, realized it was perfect for bookmarks and notes that could be repositioned. They turned it into Post-it Notes, now a staple of offices and homes worldwide. Sometimes, failure just needs the right perspective to become a success.

4. Velcro

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In the 1940s, Swiss engineer George de Mestral went for a walk and noticed burrs clinging stubbornly to his clothes and his dog’s fur. Curious, he studied them under a microscope and saw their tiny hooks, which gave him the idea for Velcro. It took years to perfect, but his accidental discovery led to one of the most convenient fasteners ever. Now, we have an easy way to stick things together without fussing with zippers or laces.

5. Corn Flakes

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In the late 1800s, John and Will Kellogg were trying to make a new type of bread when they accidentally left a batch of boiled wheat sitting out too long. Instead of tossing it, they rolled it out and discovered it formed crispy flakes when baked. This happy mistake led to the creation of Corn Flakes, which became a breakfast sensation. One forgetful moment turned into a billion-dollar industry.

6. Safety Glass

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A French chemist, Édouard Bénédictus, knocked over a glass flask in his lab and was surprised when it didn’t shatter. He realized it had been coated with a plastic solution that held the pieces together. Inspired by this accident, he developed safety glass, which is now used in car windshields and buildings. A small spill turned into a lifesaving invention.

7. Slinky

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In the 1940s, a naval engineer named Richard James tried to create stabilizing springs for ships when one fell off his desk and started “walking” across the floor. Instead of seeing it as a failed project, he realized it could be a fun toy. He and his wife turned it into the Slinky, which became an instant hit. A simple accident turned into one of the most iconic toys of all time.