How Everyday Accidents Shaped the World’s Most Useful Inventions

The dish could have gone straight into the trash. In 1928, Alexander Fleming noticed mold growing on a petri dish containing Staphylococcus bacteria, and the area around the mold was clear of bacterial growth. That small, clean ring was the important part. Fleming studied the phenomenon and identified the antibacterial substance later known as penicillin. The medicine did not become widely available because of Fleming alone; later scientists had to develop ways to purify and produce it at scale. Even so, his observation opened the door.