Brilliant Inventions Nobody Saw Coming

We like to picture the inventor as a brain on fire, sprinting to the blackboard the instant lightning strikes. The truth is usually funnier. Plenty of major discoveries owe everything to a moment of distraction, a dish left out or a walk in exactly the wrong spot. Science sometimes moves forward thanks to people who never tidied their desk.

Here are five perfectly true stories, the kind that might rescue you one day in a quiz.

The dish Fleming forgot to wash

Summer 1928. Alexander Fleming, a bacteriologist at St Mary's Hospital in London, heads off on holiday and leaves his staphylococcus cultures lying around. His reputation for untidiness, confirmed. When he gets back, one of the Petri dishes has been contaminated by a greenish mould, a fungus of the Penicillium genus. Nothing remarkable, except for one detail: around the mould, the bacteria have vanished. A clean circle, as if the fungus were holding the microbes at bay.

Fleming works out that some substance produced by the mould is killing the bacteria. He names it penicillin. It would take until the 1940s, though, and the dogged work of Howard Florey and Ernst Chain at Oxford, to turn this curiosity into a drug you could mass-produce. The three men shared the Nobel Prize in Medicine in 1945. All because a badly shut window had let a single spore drift in.

A chocolate bar melted in a pocket

1945, the Raytheon factory in the United States. Percy Spencer, a self-taught engineer tinkering with radars, is standing near a running magnetron, the tube that generates microwaves. He feels something sticky in his trousers. The chocolate bar he kept in his pocket has melted, with no heat source in sight.

Curious rather than annoyed, Spencer tries the experiment with corn kernels, which burst into popcorn in front of his colleagues. Then with an egg, which explodes in the face of a bystander who leaned in for a closer look. The principle is right there: microwaves agitate water molecules and heat matter from the inside. The first commercial oven, the Radarange, came out in 1947. It weighed more than 300 kilos and cost a fortune. Yours sits on the worktop and reheats the coffee you forgot two hours ago.

The failed glue that made the Post-it

In 1968, Spencer Silver, a chemist at 3M, is trying to make an ultra-strong adhesive. He gets the opposite: a glue so weak it barely holds and peels off without leaving a trace. A failure, on the face of it. Silver believes in it anyway and pitches his glue internally for years, convincing almost nobody.

The spark comes from a colleague, Art Fry, a choir singer in his spare time. Fed up with his bookmarks falling out of his hymn book, he thinks of Silver's useless glue. A slip of paper that holds and then lifts off cleanly: the perfect bookmark. 3M launched the Post-it in 1980. A glue written off as too rubbish for its original job became one of the best-selling office objects in the world.

The burrs that inspired Velcro

1941, somewhere in the Alps. George de Mestral, a Swiss engineer, comes home from a walk with his dog and finds his clothes and the animal's coat covered in burrs, those small sticky plant balls. Instead of cursing, he slips one under his microscope.

What he sees fascinates him: the burr bristles with tiny hooks that catch on the loops of fabric and fur. It would take him about ten years to reproduce the mechanism in nylon, a strip of hooks against a strip of loops. The patent was filed in 1955. The name comes from French: velours (velvet) and crochet (hook). Next time you hear the rasp of a child's shoe being ripped open, thank a dog and its bad habit of rummaging through the bushes.

The tart the Tatin sisters supposedly ruined

Late 19th century, in Lamotte-Beuvron, in the Sologne region. Sisters Stéphanie and Caroline Tatin ran a hotel popular with hunters. The legend, and it should be taken for what it is, says that Stéphanie, run off her feet, let her apples caramelise too long in butter and sugar. To salvage things, she laid the pastry on top, put it in the oven, then flipped the whole thing over just as she served it.

That upside-down turn is what gives the dessert its charm. The recipe made its way to Paris, popularised in particular by the restaurant Maxim's and by the food critic Curnonsky. Historians doubt the accident happened exactly like that, but the idea of baking a tart the wrong way up has certainly carried across the century.

Five stories, one common thread: chance only rewards those who look at the forgotten dish instead of tossing it. Fleming could have washed everything and walked away. Keep this for your next game instead: the word Velcro isn't some English brand that fell from the sky, but velvet and a hook, both good and French.