A discovery by itself isn’t necessarily a planned event. Stumbling upon something unexpected when you weren’t looking for it or when you were looking for something completely different can often be an ecstatic experience. Some of the people mentioned in this list have had such an experience, and many of their finds are now part of our everyday lives. Here are ten of these interesting accidental discoveries people made.

1 In 2009, a researcher received a grant to explore novel materials for applications in electronics. When he tried heating the oxides of manganese, yttrium, and indium at 1,093 °C (2,000 °F), he inadvertently found the bluest blue pigment to date. 

Professor Mas Subramanian of Oregon State University received a National Science Foundation grant in 2008. As part of the project, he began exploring his area of interest – synthesizing multiferroics (materials that exhibit a combination of ferromagnetism, ferroelectricity, and ferroelasticity). He told his then-graduate student Andrew E. Smith to heat up YInO₃ and YMnO₃. They did not get what they wanted but to their surprise realized that the resultant material has a very vibrant, brilliant blue color.

Subramanian knew its potential as a blue pigment and patented it. The YIn_0.8Mn_0.2O₃ blue or “YInMn blue” is non-toxic and a better alternative to the commonly available paint pigments like Prussian blue, ultramarine, or cobalt blue which is a known carcinogen and could cause cobalt poisoning. It is also chemically stable and does not fade. (source)

2 In 2015, researchers testing the efficiency of mosquito repellents used a Victoria’s Secret perfume on a whim. To their surprise, they found that it does the job better than many commercial repellents. 

When looking for prey, mosquitoes use their heat, visual, and olfactory sensors. Their antennas have over 72 different odor receptors that are devoted to smelling blood, and at least 27 of them also sniff out sweat. Many mosquito repellents use this fact to do their work, and a study conducted by a group of researchers at New Mexico State University tested the efficiency of 10 of these commercially available products.

The research team used groups of two different types of mosquitoes – the yellow fever mosquito known to carry the Zika virus and the Asian tiger mosquito known to transmit dengue fever and chikungunya. Along with the standard mosquito repellents, the team also tested Avon’s Skin So Soft bath oil and, interestingly, Victoria’s Secret perfume Bombshell as one of the test subjects received it as a birthday gift.

Interestingly, the perfume effectively kept both types of mosquitoes away for two hours while the bath oil could only repel one type. However, the researchers also noted that they used almost 0.5 milliliters of the perfume. So, at normal concentrations, the perfume would not be that effective. (source)

3 In 1836, a sewer worker found an old drain that led directly to the gold vault of the Bank of England. He then wrote letters to bank directors asking them to meet at the hour of their choosing in the vault and popped out of the floor to meet them. 

The 320-year-old Bank of England is home to over 40,000 bars of gold worth over £100 billion and, after the New York Federal Reserve, is the largest keeper of the precious metal in the world. According to the bank, the close call in the Victorian times was the only successful break-in, though the sewerman had no intention of robbing. After the initial shock, the bank awarded the man £800 (worth £89,761.62 as of 2018) for his honesty. (source)

4 In 2012, a 10-year-old girl from Kansas City, MO accidentally discovered a new molecule called tetranitratoxycarbon in a science class using a ball-and-stick model. 

When fifth-grade science teacher Kenneth Boehr gave out the usual ball-and-stick models to his students, Clara Lazen connected them in a unique and complex way. When she asked if she’d made a real molecule he was stumped, so Boehr sent a photograph of the model to chemist friend Robert Zoellner at Humboldt State University. When Zoellner was unable to find the molecule in the Chemical Abstracts database, he realized that it was a completely new but definitely viable chemical.

Zoellner wrote a paper on the molecule tetranitratoxycarbon, molecular structure C(CO₃N)₄, which was published in Computational and Theoretical Chemistry and credited Boehr and Lazen as co-authors. Being a compound made of carbon and nitrogen and rich in oxygen, it is believed to be thermally unstable and probably explosive. (1, 2)

5 In 1943, a naval mechanical engineer invented the Slinky when he was developing springs to make instruments stable and knocked one from a shelf. He watched in amazement how the spring gracefully “stepped” down to a stack of books, then to the tabletop, and to the floor. 

The gravity-defying tricks a Slinky can perform made it one of the most popular toys since its creation, and still interests adults and children alike to this day. Its creator, Richard James, a naval mechanical engineer, teamed up with his wife, Betty, to market it and sell it as a toy. She came up with the name “Slinky” after looking up in the dictionary and finding the word to mean “sleek and graceful.”

The James couple took out a loan of $500 to establish James Industries. They were initially unsuccessful at selling the 400 hand-wrapped, 2.5-inch, 98-coiled toys which they priced at $1 each. But in November 1945, they were given permission to set up an inclined plane to exhibit the toys in Gimbels department store in Philadelphia. Within the first 90 minutes, all 400 of them were sold. James expanded his business after developing a machine that could manufacture a Slinky in seconds, and soon he was selling millions of them. (source)