Top 10 Scientific Discoveries Made by Accident

Top 10 Accidental Scientific Discoveries

Welcome to WatchMojo, and today we’re counting down our picks for the Top 10 Accidental Scientific Discoveries.

For this list, we’ll be looking at the top scientific discoveries made during unrelated experiments, or completely by accident.

Which of these discoveries do you think was the most impressive? Be sure to share with us in the comments below.

#10: Gunpowder

9th Century
This has to be one of the most ironic discoveries in history. Chinese alchemists were experimenting with life-lengthening elixirs with the ultimate goal of finding eternal life. For centuries, potassium nitrate, also known as saltpeter, had been a staple in medical compounds. When one alchemist mixed saltpeter with sulfur and charcoal, the mysterious powder brought about explosive results. The substance led to burned hands and faces, and the structure they were working in burned to the ground. What was supposed to be the elixir for immortality was soon weaponized, ultimately leading to the ending of countless lives throughout history.

#9: Natural Radioactivity

1896
We can thank storm clouds for this discovery. French scientist Henri Becquerel was experimenting with uranium crystals during a sunny day. He believed that sunlight shining through uranium salts could burn images onto photographic plates. As storm clouds rolled in, Becquerel packed up his supplies to continue the experiment on another sunny day. A few days later, he unpacked his supplies from a drawer and found that the salts had burned a shadow onto the plate, even without the sun’s help. While Becquerel discovered natural radioactivity, the phenomenon would not receive a name until Pierre and Marie Curie coined it.

#8: Smart Dust, AKA Neural Dust

2003
Graduate school brought about this revolutionary discovery. During her program at the University of California, San Diego, student Jamie Link was working on a silicon chip in an attempt to produce a sort of film on a crystalline layer. The chip shattered during her work, but, instead of scrapping the project and starting over, Link investigated the shattered pieces of the chip. She realized that the tiny bits were still sending signals and acting as small sensors. The self-assembling particles earned the moniker “smart dust”, and with good reason. They have the potential to revolutionize medicine. Sometimes, broken things can be very beautiful.

#7: Viagra

1992
This was definitely what you could call a happy accident. Viagra, which then went by the less sexy name “UK92-480”, was initially developed by Pfizer to treat angina, or chest pain caused by reduced blood flow to the heart. During the clinical trial for the new medicine, male participants reported a, uh, sizable improvement in a different area. Apparently, the pill helped blood flow to other parts of the body. Unfortunately, the drug did little to treat angina, but its unexpected side effects addressed another issue. Once it got a name change and a new PR spin, the little blue pill became a goldmine.

#6: Vulcanization

1839
The tires on vehicles that safely carry us are actually the result of an accident. While rubber had been used for years for waterproof shoes, most people did not see much potential beyond footwear. However, scientist Charles Goodyear disagreed. He experimented to make rubber more durable and expand its uses, but his best discovery was a complete accident. In the midst of showing off his newest composite, he dropped it on a hot stove. Once it cooled and was removed from the stove, Goodyear realized the rubber was much stronger than before. The accident had weatherproofed the rubber, and the process of vulcanization was discovered. The Goodyear Tire and Rubber Company we still know today was later named after Charles Goodyear himself.

#5: X-Rays

1895
No bones about it, this discovery is pretty amazing. Physicist and professor Wilhelm Röntgen was conducting an experiment to see if cathode rays could pass through glass. During the experiment, an odd green light actually projected onto a fluorescent screen nearby, even though the cathode tube was covered. Röntgen investigated further, and discovered that while the light could pass through most substances, including human skin, it couldn’t penetrate through others, including human bone. The accidental discovery earned Röntgen the first-ever Nobel Prize in physics, and completely changed how physicians diagnosed bone fractures and other issues.

#4: Teflon

1938
That's right. Your perfect omelettes or blueberry muffins were the result of an accident. Chemist Roy Plunkett was trying to develop a new, safer refrigerant in New Jersey. He and his assistant were experimenting with a chemical formula known as Tetrafluoroethylene (TFE). He froze about a hundred pressurized tanks of the substance, but, when one was opened, no gas came out. Upon further inspection, Plunkett discovered that the experimental gas had transformed into a white, waxy powder. The powder, of course, could not be used as a refrigerant, but it was highly resistant to heat and corrosion, and had low surface friction. Once the substance coated cookware, despite its now-controversial reputation, it made flipping flapjacks and creating cakes as easy as pie.

#3: Medical Anesthesia

1844
What was once simply an unsavoury party drug turned out to have lasting effects on the world of dentistry. Before the mid-1800s, nitrous oxide (or laughing gas) was used recreationally. In 1844, dentist Horace Wells attended a demonstration of the nitrous oxide and noticed that an apothecary clerk who was showing off the party drug hurt his leg while under the influence. Afterward, Wells asked the clerk if his leg hurt, and the clerk admitted he hadn’t even noticed the injury. Wells went on to experiment with laughing gas, first on himself and then on several of his patients in dental surgeries. He realized his theory was right: nitrous oxide made it so that people couldn’t feel pain. Thus, the medical world was forever changed!

#2: Microwave Ovens

1945
If engineer Percy Spencer hadn't kept a chocolate bar in his pocket at work, we might have never gotten the magic of microwaveable pizza rolls. When Spencer was working with a radar machine at the U.S. firm, Raytheon, he noticed that the chocolate bar in his pocket was melting very quickly. He figured the melting must have to do with the microwave radio signals, and set about experimenting with food and an electromagnetic field generator, in the hopes of speeding up cooking. After much experimentation, his company released the first commercial microwave oven, and changed the lives of hungry, busy… and lazy people forever.

#1: Penicillin

1928
Alexander Fleming showed us that taking a break can be good for your work… and even save lives! The Scottish scientist was in the middle of studying bacteria when he suspended his endeavors to leave on vacation with his family. When he returned, one of his batches had been contaminated with fungus, which had actually killed the bacteria. When Fleming isolated the fungus in a pure culture of bacteria, he found that the so-called “mold juice” was effective against the bacteria that caused pneumonia, scarlet fever, meningitis, and other diseases. After more experimentation and a much-needed name change, a pure compound of penicillin was produced, and modern medicine got a crucial upgrade!