The first commercial microwave oven, Raytheon’s Radarange,  was invented in the USA in the late 1940s. Domestic models began to sell in Japan in 1966 and in the US in 1967. The first imports to Australia were used mainly in take-away food outlets, but by 1980 around 150,000 households had a microwave, with penetration reaching 50 per cent by 1989 and around 77 per cent by December 1995.

The name Raytheon is one you see every time you hop off a flight at Canberra airport. They make weapons. Very big weapons. Their posters in the airport are designed to catch the eye of defence boffins as they flit around the country giving out submarine contracts and having conferences on subjects like electronic warfare and combat readiness.

So who would have thought that this same company brought us the appliance we use to defrost our fish fillets or to warm up last night’s leftovers?  Yet it was Raytheon who clinched the first patents on microwave cooking back in the 1940s.

Like other US technology giants, they were looking for ways to convert their wartime manufacturing operation into a peacetime manufacturing operation. The legend goes that one Percy Spencer noticed that stray microwave radiation (!) melted a chocolate bar in his pants pocket.  History does not record whether said radiation partially cooked his thigh, or resulted in sterility.

At any rate, Percy lodged the first patents for heating food with microwaves. These were granted in 1950 and 1951 and other Raytheon employees continued to develop the technology. Where Percy had demonstrated how microwaves could cook lobster and popcorn, the engineer who developed the first practical, commercially viable microwave oven was Marvin Bock.

His invention needed a name, so a staff competition was held. The winning entry combined the good military terms Radar and Range, to produce Radarange. The first consumer version was presented by Brock at the World’s Fair in Montreal in 1967. Marvin then went back to designing Sparrow and Hawk missiles. As you do.

In Australia, the microwave oven was initially marketed to takeaway food outlets, but by the late 1970s domestic models were beginning to gain acceptance.  In the ‘80s, we were told that this was a revolutionary way of cooking that represented a low-energy alternative to conventional cooktops and ovens. There was nothing you couldn’t cook in a microwave.

Of course, cooks (mainly women) had to learn how to use this challenging new technology. There were microwave cooking classes, usually sponsored by the manufacturers, and a spate of cookbooks telling women how to use them.

These were encyclopaedic in their approach: how the microwave oven worked; where to put the oven; what kind of cookware to use in the oven; how to defrost, roast, bake, reheat. How to boil an egg. Despite this, surveys over the years have shown that microwave ovens are mostly used for defrosting and reheating food.

Microwaves are, indeed, energy-efficient. A study by researchers at Brown University in the US found that the average microwave uses a third of the energy used by a conventional electric oven. However, many people still have lingering doubts about their safety. The CSIRO, for its part, says there’s no evidence for most of these concerns.