Facts about inventions
Most inventions arrive by accident, in the wrong order, or decades before anyone finds a use for them. Microwaves, sticky notes, safety glass and vulcanised rubber all started as mistakes or side effects. The facts here trace how the thing actually came about, note who noticed the accident and why it mattered, and point at a source so you can follow the full story if it hooks you.
The Slinky was invented by accident by a naval engineer trying to stabilise ship instruments.
In 1943, Richard James knocked a spring off a shelf and watched it walk down onto a pile of books. His wife Betty named it Slinky, and the first 400 sold out in 90 minutes at a Philadelphia department store.
The microwave oven was invented after a radar engineer noticed the chocolate bar in his pocket had melted.
In 1945, Percy Spencer was testing a magnetron, the tube that generates radar waves, when the snack in his pocket turned to goo. He then tried popcorn, which popped, and an egg, which exploded.
Bubble wrap was originally invented as textured wallpaper.
In 1957, engineers Alfred Fielding and Marc Chavannes sealed two shower curtains together, trapping air bubbles, and tried to sell the result as wall covering. Nobody wanted it. They then tried greenhouse insulation, which also failed.
Velcro was invented after a walk in the Alps left a dog covered in burrs.
In 1941, Swiss engineer George de Mestral came home from hunting and examined the burdock burrs stuck to his trousers and his dog under a microscope. He saw hundreds of tiny hooks catching on loops of fabric.
Play-Doh was sold as a wallpaper cleaner for more than 20 years before it became a toy.
The putty was made in Cincinnati from the 1930s to wipe coal soot off wallpaper. When cleaner heating systems killed the market, a nursery school teacher noticed children loved modelling with it.
Post-it Notes exist because a scientist failed to invent a super-strong glue.
In 1968, 3M chemist Spencer Silver was trying to make a powerful adhesive and instead produced one that was weak and could be peeled off again. For years nobody could think of a use for it.
The first documented computer bug was an actual moth stuck in a relay.
In September 1947, operators of the Harvard Mark II computer found a moth trapped inside one of its relays and taped it into the logbook with the note: first actual case of bug being found. The logbook page is now in the Smithsonian.
The QWERTY keyboard dates from the 1870s, and the story that it was designed to slow typists down is a myth.
Christopher Latham Sholes rearranged the keys of his typewriter several times before settling on the layout sold by Remington in 1874. The order probably reduced jams by separating some common letter pairs, and was also shaped by telegraph operators' needs.
The world's first webcam was set up to watch a coffee pot.
In 1991, researchers at the University of Cambridge computer lab pointed a camera at the coffee machine in the Trojan Room so they could check from their desks whether it was worth the walk. It went online for the whole world in 1993.
The safety pin was invented in a few hours by a man who needed to pay off a 15-dollar debt.
In 1849, New York mechanic Walter Hunt twisted a piece of brass wire into a pin with a spring and a clasp that covered the point. He sold the patent for 400 dollars, paid his debt and never saw another cent from it.
The tin can was invented almost 50 years before the can opener.
Canned food appeared in 1810, and early cans were so thick that instructions said to open them with a chisel and hammer. Soldiers used bayonets or shot them open. The first dedicated can opener was patented in 1855 in Britain and 1858 in the United States.
The first American alarm clock could only ring at 4 o'clock in the morning.
Levi Hutchins of New Hampshire built it in 1787 so that he would never oversleep, and he only ever needed one wake-up time. The mechanism had no way to set a different hour.