Serendipity-doo-dah: Some of the best accidental inventions

As the saying goes, you'll never know unless you try and plenty of unexpected successes have came from luck or apparent failures. We take a look at some of the best examples.


Where would we be without a microwave to heat up last night’s leftover curry? Thanks to Percy Spencer, we don’t have to find out. He discovered the microwave oven accidentally while inspecting a magnetron. When he was in front of the device, a chocolate bar melted in his pocket. In 1945, the microwave oven was born.

Percy Spencer.

Post-it Notes

In 1968, 3M scientist Spencer Silver was attempting to develop a super-strong adhesive when he accidentally created a “low-tack”, reusable, pressure-sensitive adhesive. Silver promoted his new product unsuccessfully for five years until, in 1974, his colleague,  Art Fry, came up with the idea of using the adhesive to anchor his bookmark. Incidentally, the notes’ yellow colour was also chosen by accident, as the lab next-door to the Post-It team only had yellow scrap paper to use.

Art Fry.


All John Pemberton wanted to do was cure headaches. The pharmacist was experimenting with two main ingredients for his cure – coca leaves and cola nuts. When his lab assistant accidentally mixed the two with carbonated water, the result was the world’s first Coca-Cola.

John Pemberton.


Wilson Greatbatch was on the hunt for a solution for “heart block”, a condition in which a heart does not receive messages from surrounding nerves to pump blood correctly. Greatbatch intended to create a machine to mend a broken heart. While building an oscillator to record heartbeat sounds in animals in 1958, he accidentally grabbed the wrong transistor and installed it in his device. When he switched it on, he heard the rhythmic pulsing pattern similar to a heart. His accidental invention, the pacemaker, was ideal for pulsating signals to the heart.


Electrical engineer George De Mestral noticed how perfectly cockleburs bound to his dog’s fur when he returned from a walk. So he developed a material that attached firmly but could also be easily torn apart – Velcro. It wasn't successful at first, but NASA eventually saw the appeal for space suits and zero gravity and kids lapped up the 'space age' material.

George De Mestral.

Gun Powder

Around 2,000 years ago, Chinese alchemists started experimenting with nitre and sulphur for medicinal use. By the 9th century, Taoist monks revived these in their search for a source of immortality and, rather than finding a cure for death, created the substance that would be the first military-grade gunpowder, which soon became to spread across the globe, ending millions of lives in cruel irony.


Swiss scientist Albert Hoffman began researching lysergic acid derivatives in 1938, hoping to find a new repertory analeptic. Five years later, he took up the experiments again and accidentally absorbed some through his finger-tips, which induced a “not unpleasant intoxicated-like condition, characterized by an extremely stimulated imagination”. Three days later, he intentionally imbibed 0.25 milligrams. “Kaleidoscopic, fantastic images surged in on me,” he wrote later, “alternating, variegated, opening and then closing themselves in circles and spirals, exploding in colored fountains, rearranging and hybridizing themselves in constant flux ...”

Albert Hoffman.


In 1938 scientist Roy Plunkett was working on a way to make refrigerators more home friendly and searching for a way to replace the current refrigerant. After opening one sample’s container, he found his experimental gas was all gone. All that was left was a slippery resin that was resistant to extreme heat and chemicals. Teflon was originally used in the 1950s in the automotive industry. It wasn’t until the 1960s that it would be used for its most noted application – non-stick cookware.

Roy Plunkett.


Pharmaceutical researchers Simon Campbell and David Roberts developed a drug they hoped would treat high blood pressure and angina in the 1980s. Early clinical trials showed an unexpected side effect and Pfizer launched a new clinical trial to use the drug for erectile dysfunction disorder. The trial proved successful and Viagra hit shelves in 1998.


One of the world’s most famous accidental inventions is the discovery of penicillin. Scottish bacteriologist Alexander Fleming returned from a holiday in 1928 and discovered one of his petri dishes had grown a mysterious mould. Fleming observed the existing bacteria in the dish did not grow where the mould grew – indicating its potential in staving off unwanted microorganisms.

Alexander Fleming.

Potato Chips

Sometime things get invented multiple times, independently, and in different parts of the world. So, while the potato chip had actually already been invented, George Crum, a chef in Saratoga Springs, New York in 1853, got fed up with a customer repeatedly returning his food, complaining that his French-fried potatoes were too fat. In a rage, Chum cut the potatoes so thin that they fried to a crisp. The customer loved them. And now we do too.

This story originally appeared on pages 70-71 of Idealog issue 62.
