The microwave celebrates its 75th anniversary this year and like many great inventions, its existence is down to a combination of scientific genius and a lightbulb moment.
Unlike other inventions, squirrels and the Titanic also played a key role.
By the 1930s scientists in various countries had come to realise that when radio waves hit an object, part of the wave is reflected back. This enables you to detect objects and calculate their distance and speed – radio detection and ranging became known as radar.
Large radar stations were built on Britain’s east coast, to give advance warning of Geman bombing raids, allowing fighter planes to engage before the bombers reached their target. Many experts believe without this technology the Battle of Britain would have been lost.
In 1940 a secret delegation of British scientists arrived in the US carrying what one American historian subsequently described as “the most valuable cargo ever carried to our shores.”
That cargo was a cavity magnetron which effectively allowed reflected “microwaves” to be measured on much smaller receivers. Instead of a fixed radar station the device could fit in a portable case – and fitted on aircraft, submarines and planes.
The US company Raytheon was awarded a wartime military contract to develop radar and playing a lead role in the team was Percy Spencer.
In 1912 as news of the sinking of the Titanic spread around the world Percy, then a teenager growing up in Maine, was so inspired after reading of the bravery of the wireless operators on the ship that he signed up to join the US Navy.
From a poor background, Percy had a love of nature and an interest in science. Instead of using what few cents he had to buy chocolate bars, he preferred a peanut cluster bar so he could share with squirrels and chipmunks during school breaks.
He had been fascinated by the introduction of electricity to his home area and despite having no training and aged just 14, he was part of the team that installed it in a local mill. In the navy he became similarly fascinated by wireless communication and joined Raytheon when returning to civvy street after World War 1.
In 1946 whilst standing beside a magnetron device Percy discovered the peanut bar in his pocket had melted. If it had been a chocolate bar this might not have raised an eyebrow, but realising melting a peanut cluster required a far higher temperature Percy was intrigued.
He devised a box to harness the microwaves and set about experimenting with various other foods. It was the birth of the microwave oven and just one year later the first one became available commercially with a price tag equivalent today to £20,000.
Nowadays a microwave will cost under £100 and an estimated 93% of British homes have one – that’s more than have a car or a digital TV.
So, next time you pop food into the microwave give thanks that over a century ago a kindly schoolboy in Maine preferred sharing peanuts with squirrels to scoffing chocolate.
About Oliver Parkinson
Sous Chef of SK Foods.
Your food. Our Passion.
