40 Fun Facts About Microwave Ovens

In a famous story, what melted in an engineer's pocket near wartime equipment and inspired the microwave oven?

A candy bar going soft made the engineer curious enough to try the same waves on other foods. He was not the first to notice the effect, only the first to investigate it.

Popcorn was the first food cooked on purpose with microwaves; which food came second and exploded?

An egg came second, and it burst in the face of a colleague who had leaned in for a closer look. Steam builds up inside the shell with nowhere to go.

The microwave oven grew out of an engineer's work on which Second World War detection technology?

Radar sets ran on powerful microwave tubes, and by the war's end one American firm was building 2,600 of those tubes a day. The oven simply pointed the same waves at dinner.

What one-time payment did the inventor of the microwave oven receive from his employer for the patent?

Two dollars was the token sum his employer paid every staff inventor for a company patent. He earned no royalties, though he did rise to senior vice president.

Contrary to kitchen lore, which metal item can usually sit in a running microwave oven without sparking?

A soup spoon has no pointed ends, so electric charge has nowhere to pile up and leap through the air. A fork's tines do the opposite, which is why they throw sparks.

Mystery radio bursts at Australia's Parkes Observatory came from staff doing what to a microwave oven?

Opening the door early let out a brief radio pulse as the oven shut down, and it looked like a signal from deep space. Astronomers had named the bursts perytons before solving the case in 2015.

Microwave ovens run at about 2.45 gigahertz, a band shared with which wireless technology they can disrupt?

Wi-Fi uses the same unlicensed 2.4 GHz band, so a little leakage from a running oven can slow a nearby connection. Bluetooth shares the band too.

Microwaves are absorbed in the outer layer of a thick food; which process then carries heat to the centre?

Conduction finishes the job, passing heat inward just as it does in a conventional roast. The belief that microwave ovens cook food from the inside out is a myth.

The first commercial microwave oven stood nearly six feet tall; roughly how much did it weigh?

750 pounds of machinery drew three kilowatts, about triple a modern model. The first units were leased to hotels and restaurants rather than sold.

Which small fruit, cut in half, became an internet party trick for sparking in a microwave oven?

A grape sparks because its two watery halves trap the waves and create a hotspot where they touch, physicists showed in 2019. The trick had gone unexplained for over twenty years.

Which self-taught engineer, who never finished grammar school, is credited with inventing the microwave oven?

Percy Spencer was orphaned young, went to work in a spool mill at twelve and taught himself calculus and physics on night shifts. He ended his career with 300 patents.

Which American maker of guided missiles patented the microwave oven after an employee's accidental discovery?

Raytheon filed the patent in October 1945 and brought out the first commercial model two years later. The firm went on to build the Patriot missile.

Which vacuum tube, developed in Britain for wartime use, generates the waves inside a typical microwave oven?

Magnetron tubes turn high-voltage electricity into microwaves. Britain handed a sample to America in 1940, and a US historian later rated it the most valuable cargo ever landed there.

The metal mesh in a microwave oven's window helps the cooking chamber work like which piece of physics apparatus?

Faraday cage shielding works here because the holes in the mesh are far smaller than the 12-centimetre waves, which bounce back. Visible light has a much shorter wavelength and slips through.

Water warmed in a smooth mug in a microwave oven can pass boiling point without bubbling; what is this called?

Superheating leaves the water looking calm until a nudge or a pinch of sugar disturbs it, when it can erupt out of the cup. A scratched mug gives bubbles somewhere to start.

Which Japanese electronics company introduced the first microwave oven with a turntable in the 1960s?

Sharp added the spinning plate in the mid-1960s, a few years after it began making ovens. Its founder's Ever-Ready Sharp pencil of 1915 gave the firm its name.

Which Iowa refrigerator maker, owned by a defence firm, launched the first popular countertop microwave oven?

Amana put its countertop model on sale in 1967 for $495, two years after the takeover. The brand grew out of Iowa's communal Amana Colonies.

Which Ohio stove company licensed the technology and sold the first microwave oven built for home kitchens?

Tappan put its built-in model in showrooms in the mid-1950s at about $1,250, a price that kept sales small. The first popular countertop model was still a decade away.

On a conventional microwave oven, how does a low power setting such as defrost actually reduce the heating?

It switches on and off every few seconds, so half power really means full power for half the time. Pricier inverter models can hold a steady lower output instead.

What problem is the rotating turntable inside a microwave oven designed to reduce as food cooks?

Cold spots form because the waves settle into a fixed pattern of strong and weak patches, so the turntable carries food through both. Ovens without one hide a fan-like stirrer in the roof that scatters the waves instead.

The microwave oven's inventor joined the US Navy after reading about the wireless operators on which ship?

Titanic wireless operators caught his imagination as a teenager in rural Maine, so he enlisted at eighteen. He then taught himself radio from textbooks while standing watch at night.

Penzias and Wilson won a Nobel Prize for detecting faint microwaves left over from which event?

The Big Bang left a faint glow that still fills the universe, and the pair picked it up by accident in the 1960s with a horn antenna in New Jersey. It became key evidence for the theory.

On the electromagnetic spectrum, microwaves sit between ordinary radio waves and which other kind of radiation?

Infrared waves are shorter than microwaves, while ordinary radio waves are longer. The borders are loosely drawn, and microwaves are often counted as simply the shortest radio waves.

Microwave oven radiation lacks the cancer risks of X-rays because it belongs to which category of radiation?

Non-ionizing radiation can heat food but cannot make it radioactive. The waves vanish the moment the power stops, just as light does when a lamp goes dark.

Which Joe Dante horror comedy features one of its small monsters exploding inside a microwave oven?

Gremlins staged the blast with a balloon that was allowed to burst. One scholar has linked the scene to urban legends about pets dying in microwave ovens.

Which film was sued by a science writer over a line claiming microwave ovens take the nutrition out of food?

American Hustle has Jennifer Lawrence's character Rosalyn credit the claim to writer Paul Brodeur, who sued. A California appeal court found nobody would take her words as fact.

Which Dire Straits hit is voiced by a worker at a store selling televisions, refrigerators and microwave ovens?

Money for Nothing began when Mark Knopfler watched a deliveryman in a New York appliance shop react to the music videos on the display sets. It spent three weeks at number one in America.

Which microwaveable turnover brand, launched by brothers Paul and David Merage, came in a crisping sleeve?

Hot Pockets came in a sleeve with a silvery lining that heats up in the oven to crisp the crust. The brothers sold their company to Nestlé in 2002 for $2.6 billion.

What is the technical name for the thin metallised patch that absorbs microwaves inside a popcorn bag?

A susceptor soaks up microwave energy and grows very hot, concentrating heat on the oil so the kernels pop quickly. Pies and other crisp-crust foods use the same trick.

Which butter-flavour chemical in microwave popcorn was linked to a serious lung disease among factory workers?

Diacetyl fumes scarred the small airways of workers who breathed them for years, a condition nicknamed popcorn lung. Major brands then removed the ingredient from their bags.

Thelma Pressman, founder of America's first microwave cooking school, was often likened to which television chef?

Julia Child of microwave cooking was Pressman's nickname. She started the school in Encino, California, in 1969 and later wrote a column for Bon Appétit magazine.

By 2020, which Chinese company made most of the countertop microwave ovens sold in the United States?

Midea builds ovens that are sold under many other brand names, so rivals on the same shelf can be near twins inside. The company started out in 1968 making bottle lids.

Microwave ovens use an ISM band, radio spectrum set aside for industrial, scientific and which other uses?

Medical heat-therapy machines share the band with ovens. Because nobody needs a licence to transmit there, cordless phones and baby monitors later moved in too.

Which company cooked steaks in minutes with a shortwave radio transmitter at the 1933 Chicago World's Fair?

Westinghouse placed the food between two metal plates wired to a 10-kilowatt transmitter, more than a decade before the microwave oven. Potatoes cooked just as quickly.

At which English university did Randall and Boot build the 1940 tube that later powered microwave ovens?

Birmingham physicists Randall and Boot built a tube that gave ten-centimetre microwaves at far higher power than earlier designs, enough for compact radar. Within months Britain shared the design with America.

Food rarely browns in a microwave oven because it seldom gets hot enough for which chemical process?

Maillard reaction browning needs temperatures well above boiling, and watery food in a microwave oven stalls near boiling point. Bacon is the exception, because fat gets far hotter.

A 2006 study found two minutes in a microwave oven killed 99% of certain bacteria in which wet kitchen item?

A sponge soaked through and microwaved at full power lost more than 99% of its bacteria. A 2017 study cast doubt on the tip: sponges their owners cleaned regularly carried more of some worrying species.

Which leafy vegetable keeps nearly all its folate in a microwave oven but loses about three-quarters when boiled?

Spinach loses about 77% of its folate to the cooking water when boiled and drained. Microwaving needs little or no water, so far less of the vitamin washes away.

Which marshmallow treat do fans send jousting by heating two in a microwave oven, each armed with a wooden stick?

Peeps swell in the heat, and the chick that puffs up biggest and deforms its rival wins the joust. The sugary chicks have been made by Just Born since 1953 and are sold mainly at Easter.

Which organs are most vulnerable to intense microwaves because parts of them lack blood vessels to carry heat away?

The eyes cannot cool the lens and cornea through blood flow, so strong exposure can cook the proteins of the lens into a cataract. A household oven's shielding keeps exposure far below that level.