10 Times Scientists Made Accidental Discoveries That Changed the World
Some of the world’s most significant breakthroughs, from penicillin to microwaves, were born from happy accidents, proving that curiosity and chance can change history forever.
- Alyana Aguja
- 3 min read
History is full of instances where random meetings and encountering errors ignited revolutionizing discoveries—from lifesaving antibiotics to common-place comforts such as microwaves and Velcro. These happy accidents remind us that innovation often results from the unanticipated, when keen attention is met with serendipity. At times, the biggest strides are made when we’re not even attempting.
1. Penicillin
Image from Nobel Prize
In 1928, Alexander Fleming returned from vacation to find a mold called Penicillium notatum, had contaminated his petri dishes, killing the surrounding bacteria. Instead of discarding it, he investigated further and discovered the first antibiotic. This chance observation revolutionized medicine, saving countless lives from bacterial infections.
2. Microwave Oven
Image from Mass Moments
Percy Spencer, a 1940s engineer, observed a chocolate bar in his pocket melted when he was standing close to a magnetron (a radar device). Intrigued, he placed popcorn kernels and even an egg close to the machine, both of which had dramatic responses. Thus, the microwave oven was invented, revolutionizing how people prepare food.
3. X-Rays
Image from Wikipedia
In 1895, Wilhelm Röentgen was working with cathode rays when he saw a fluorescent light from a screen nearby, although it was covered. He was curious and knew he had found a new type of invisible radiation—now known as X-rays. This serendipitous discovery revolutionized medical diagnosis, allowing us to look inside the human body without surgery.
4. Velcro
Image from National Inventors Hall of Fame®
In 1941, Swiss engineer George de Mestral observed burs sticking obstinately to his dog’s coat while going for a stroll. Intrigued, he studied them using a microscope and observed their hook-like shape. He went on to invent Velcro, a fastening method that found utility in fashion, aerospace, and consumer products.
5. Pacemaker
Image from The New York Times
In 1956, engineer Wilson Greatbatch accidentally put in the incorrect resistor when constructing an oscillator, producing electrical pulses that resembled a human heartbeat. Seeing the potential, he developed the design into the first implantable cardiac pacemaker. The device has since saved millions of lives by controlling heart rhythms.
6. Teflon
Image from Science History Institute
In 1938, Roy Plunkett was researching refrigerant gases when he accidentally discovered a weird, slippery white material. This was the discovery of polytetrafluoroethylene, later renamed Teflon. Its non-stick surface changed the world of cookware and was used for aerospace and industrial purposes.
7. Post-it Notes
Image from National Inventors Hall of Fame®
Spencer Silver was attempting to develop a super-strong glue in 1968 and wound up with a repositionable one that was weak. Years later, a co-worker used it to hold his bookmarks in a hymnbook, inspiring the invention of Post-it Notes. This humble product became an international office standard.
8. Safety Glass
Image from Chemistry Europe - Wiley
In 1903, Édouard Bénédictus dropped a glass flask with a cellulose nitrate coating by accident, and much to his amazement, it cracked but did not break. Seeing its potential, he invented the safety glass, which found its way into car windshields and safety equipment. It greatly minimized injury from shattered glass.
9. Vulcanized Rubber
Image from Wikipedia
In 1839, Charles Goodyear spilled rubber dissolved in sulfur onto a hot stovetop. Rather than melting, the mixture hardened to become tough, elastic, and resistant to the weather. Such was the luck of serendipity when modern rubber items, from automobile tires to water-resistant materials, were developed.
10. Artificial Sweetener (Saccharin)
Image from Find a Grave
In 1879, chemist Constantin Fahlberg did not wash his hands after experimenting with coal tar derivatives and tasted a sweet flavor on his hands while having dinner. He traced it back to his experiments and found saccharin, the first artificial sweetener. This revolutionized the food industry by offering a substitute for sugar to millions.