Join Catherine McGuinness for  The story of 10 scientific discoveries that changed the world – and were all discovered by accident!


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Some of the greatest scientific breakthroughs have been accidentally discovered from within a laboratory

Misjudging or miscalculating in the lab can be hugely costly for a research team – having invested significant time, money and effort into an unsuccessful venture. However, sometimes lab workers get lucky and accidentally discover a scientific principle or breakthrough which would otherwise have remained unknown. Here we have a look at ten of the world’s greatest accidental scientific discoveries.


One of the biggest medicinal breakthroughs in history came about entirely by accident. Sir Alexander Fleming interrupted his experimentation with the influenza virus for a two week holiday and when he returned he found that a mould had started to grow which deterred the virus. Penicillin was born and is now used to treat everything from acne to pneumonia.


A little over a century ago, the Belgian scientist, Leo Baekeland, accidentally made plastic. Originally naming the mixture of formaldehyde and phenol after himself, Bakelite, the scientist accidentally revolutionised pretty much everything in production and manufacturing.

The Microwave

As WWII was drawing to a close, engineer, Percy Spencer, was attempting to develop energy sources for radar equipment. Whilst that didn’t work out, Spencer did realise the chocolate bar in his pocket had melted, and went on to test his accidental invention by making popcorn.


The fantastically named Robert Chesebrough was so enamoured when he accidentally discovered Vaseline that he started using it for all kinds of purposes – even eating a spoonful every day. Chesebrough was originally on the hunt for oil when the petroleum jelly made itself known.

Strikeable Match

At the end of an amazing chain of events, English pharmacist, John Walker, accidentally got a lump of his fun new mixture of antimony sulphide and potassium chlorate on the end of his mixing stick. Naturally, he tried to scratch it off and it burst into flames – a terrifying but incredible breakthrough.


Most of these accidental discoveries came about as a result of scientists trying to create something similar to the final product. However, 9th century Chinese alchemists couldn’t have been further from success when they accidentally developed gunpowder. They were trying to find an elixir for eternal life.


Mauve may not be the world’s most exciting colour, but teenage chemistry student, William Perkins, will have been delighted when he accidentally created it using tree bark and coal tar. Perkins managed to isolate the colour, developing the world’s first ever synthetic dye. 

Corn Flakes

The daily breakfast of millions of people all around the world, Corn Flakes were invented when Will Keith Kellogg accidentally left some wheat on the boil. The world’s most famous cereal was created and a dynasty was born.


During the early 1800s, ether and nitrous oxide were both widely abused by folks attending ‘laughing parties’. When the laughter died down, someone pointed out the substance could help mask pain, and anaesthesia was born.