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By Luis Gustavo. See how we research and review our content.
A chocolate bar softening in a radar engineer’s pocket, a glue that refused to hold, a burr clinging to a dog’s coat: each of these began as an annoyance that somebody chose to look at twice.
Luck rarely did the whole job. In every case below, a trained person noticed something odd and then spent months or years working out what it was good for. Here are five of those moments, followed by two sections on what came next.
1. The microwave was born from a melted chocolate bar
Percy Spencer was an engineer at Raytheon, a company that made magnetrons, the vacuum tubes that generate the microwaves used in radar. Standing near an active magnetron shortly after World War II, he noticed that a chocolate bar in his pocket had melted. Retellings disagree on the candy and the exact year, so the pocket detail is a favorite story rather than a lab record. Popcorn kernels were reportedly his next test, and they popped.
The paper trail is firmer. Spencer and Raytheon filed a patent on October 8, 1945, and it was granted on January 24, 1950. The first commercial oven, the Radarange, was marketed in 1947: about six feet tall, around 750 pounds, and priced near $3,000. A version suited to homes took roughly twenty more years to arrive.
2. The Post-it note came from a “bad” glue
In 1968, Spencer Silver was working at 3M in Maplewood, Minnesota, trying to make an extra-strong adhesive. What he produced was light, removable and reusable, which counted as a miss against the brief. He spent about five years promoting it inside the company without finding a product that needed it.
Art Fry, a 3M colleague who sang in a church choir, supplied the use. His paper bookmarks kept slipping out of his hymnal, and Silver’s glue could hold a slip in place without tearing the page. The product, first called Press n’ Peel, tested poorly in several cities in 1977. Free samples handed out in Boise, Idaho, in 1978 turned that around: about 90 percent of the people who tried them said they would buy. Post-it Notes reached U.S. stores in 1980.
3. Velcro was inspired by sticky plants
In 1941, Swiss engineer George de Mestral came back from a walk with his dog covered in burrs. Under a microscope, each burr was lined with tiny hooks that grabbed the loops in fabric and fur. A fastener with hooks on one strip and loops on the other was sitting in plain sight.
Making it was the hard part. The tape needs a very dense field of hooks and loops, around 300 per square inch according to one account, which made weaving slow, and early cotton versions wore out. De Mestral found that nylon treated under infrared light formed tough hooks. The patent came in 1955, roughly fourteen years after that walk, and the name blends the French words velours (velvet) and crochet (hook).
4. The most famous artificial sweetener was discovered by accident in a lab
Saccharin came out of Ira Remsen’s chemistry laboratory at Johns Hopkins University, where a young chemist named Constantin Fahlberg noticed an unexpectedly sweet taste at dinner and traced it to a beaker from the day’s work. The discovery is usually dated to 1878 or 1879. Tasting laboratory chemicals is something modern lab rules rule out, which is part of why the story keeps getting retold.
Remsen and Fahlberg published their findings together in February 1879. Fahlberg later patented a cheaper way to make the compound and, by 1886, was claiming sole credit, which Remsen protested. Saccharin turned out to be roughly 300 times sweeter than table sugar, and it became one of the first sweeteners sold on a large scale.
5. The Slinky almost became scrap before becoming a toy
In 1943, Richard James, a naval engineer, was working on springs meant to keep sensitive instruments steady aboard ships in rough seas. One spring fell off a shelf, and instead of landing in a heap it stepped to a stack of books, then a tabletop, then the floor, where it recoiled upright.
His wife, Betty, saw a toy in it and chose the name Slinky. The couple first showed it at Gimbels department store in Philadelphia in 1945 and sold 400 in about 90 minutes. By the toy’s 50th anniversary in 1995, more than 250 million had been sold worldwide, according to MIT’s Lemelson Center.
Fleming’s neglected dish and the first antibiotic
The same pattern shows up in medicine. In 1928, before leaving for a two-week holiday, Alexander Fleming left a dish of Staphylococcus bacteria on a bench at St. Mary’s Hospital in London instead of placing it in an incubator. A Penicillium mold spore drifted into the dish, and because it sat at room temperature, both organisms grew.
Fleming saw bacteria held back near the mold and named the active substance penicillin, but he could not isolate it and did not grasp its medical promise for about a decade. In 1940, Howard Florey and Ernst Chain showed that it could treat bacterial infections, and the three men shared the 1945 Nobel Prize in Physiology or Medicine. The accident supplied the clue; the Oxford team supplied the medicine. More on that field in these facts about diseases and medicine.
Saccharin’s century of arguments with regulators
Saccharin’s safety was questioned almost as soon as it reached kitchens. In 1908, Harvey Wiley, a government chemist, pushed for a ban, and President Theodore Roosevelt, who took the sweetener himself, dismissed the worry. A 1912 U.S. rule barred it from processed foods while still allowing direct sale to consumers.
The debate resurfaced in 1972, when the FDA removed saccharin from its generally recognized as safe list, and Congress required warning labels in 1977. Around 2000, an NIEHS study judged the earlier rat research invalid, according to the Science History Institute, and the sweetener came to be regarded as safe for people. Questions about what to eat are best taken to a doctor or dietitian. For more kitchen history, see these food facts.
Other reads that fit this theme: facts about artificial intelligence few people know and facts about sound technology.
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Spencer’s pocket, Silver’s shelved glue and Fleming’s unincubated dish all became useful because someone kept looking at the result everyone else would have wiped away.