The Science Oven

A reflection on the microwave oven, perhaps the most important invention to come out of a World War that sparked a lot of them.

By Ernie Smith

Today in Tedium: Say what you will about the world in which we live, but the microwave has done more to shape it, for good and for bad, than any other individual food-cooking device. Having a device that can heat food in a matter of a couple of minutes, even if it does so terribly, is obviously a significant improvement on what came before that point. It means that people can go to the office and have a hot lunch without having to go to a restaurant or cafeteria. It simplifies prep processes in kitchens—both at home and in commercial settings. And if we did not have it, popcorn would be a huge pain to make. But there’s one thing to consider about the microwave that most people probably don’t: It was a technology largely developed during wartime by a defense contractor—by accident. Today’s Tedium leans into the radiant waves of the microwave. — Ernie @ Tedium

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You probably take this device for granted. (Patty Ho/Flickr)

Percy Spencer, the self-taught inventor who made the observation that shaped home cooking forever

Percy Spencer was one of the defense contractor Raytheon’s most important inventors, and during World War II, he had a very important job: optimize the underlying technology for radar to help work out manufacturing bottlenecks.

Spencer, considered one of the most important figures in the design of radar tubes, has a number of patents to his name, many of which involve improvements in the electron discharge tubes, particularly the cavity magnetron.

That he became the patron saint of quick-cook meals is something of a happy accident, a side effect of his work with radiation that involved, I kid you not, a candy bar.

A 1958 article on Spencer in Reader’s Digest, republished by his grandson Rod, lays out the unusual state of affairs:

One day a dozen years ago he was visiting a lab where magnetrons, the power tubes of radar sets, were being tested. Suddenly, he felt a peanut bar start to cook in his pocket. Other scientists had noticed this phenomenon, but Spencer itched to know more about it.

He sent a boy out for a package of popcorn. When he held it near a magnetron, popcorn exploded all over the lab. Next morning he brought in a kettle, cut a hole in the side and put an uncooked egg (in its shell) into the pot. Then he moved a magnetron against the hole and turned on the juice. A skeptical engineer peeked over the top of the pot just in time to catch a faceful of cooked egg. The reason? The yolk cooked faster than the outside, causing the egg to burst.

Spencer had discovered that you could cook with high-frequency radio waves. He got a patent on the “radar range,” one of the 225 he holds. The new device will cook a sirloin steak in one minute, a plump Thanksgiving turkey in little more than half an hour. Used for some time in restaurants, Pullman diners and ocean liners, radar ranges are now being produced for the home.

(I know what you’re thinking—a sirloin steak or Thanksgiving turkey in a microwave does not engender confidence. But hey, it was possible!)

Percy Spencer Patent

Percy Spencer’s first stab at the microwave oven. (Google Patents)

The primary patents he received in relation to microwave cooking, first in 1950 and later in 1952, paint the picture of someone who uncovered something important. From the 1950 patent filing:

Such energy has been used before for this purpose, but the frequencies employed have been relatively low, for example, not over 50 megacycles. I have found that at frequencies of this order of magnitude, the energy necessarily ex pended in order to generate sufficient heat to satisfactorily cook the foodstuff is much too high to permit the practical use of the process. I have further found, however, that this disadvantage may be eliminated by employing wave lengths falling in the microwave region of the electromagnetic spectrum, for example, wave lengths of the order of 10 centimeters or less. By so doing, the wave length of the energy becomes comparable to the average dimension of the foodstuff to be cooked, and as a result, the heat generated in the foodstuff becomes intense, the energy expended becomes a minimum, and the entire process becomes efficient and commercially feasible.

Of course, this story is not Percy Spencer’s alone. While Spencer assuredly deserves credit for the invention of what we call the microwave, others gave the discovery its wings, particularly Raytheon cofounder Laurence Kennedy Marshall, who saw the potential of Spencer’s discovery and decided to deeply invest in it.

As the 1974 corporate biography ‌The Creative Ordeal: The Story of Raytheon put it:

The discovery filled Marshall with enthusiasm. He knew a great deal about the problems attendant on serving food to large numbers of people—cooking it, transporting it, and keeping it properly warm. Early in the war he had realized that the great numbers of persons employed in the expanded Raytheon factories needed warm lunches and were located too far from restaurants. He had persuaded Herbert Marshall (no relation, but a Boston restaurateur whom he had known, it seemed, forever) to enter the catering business to handle that part of Raytheon’s needs.

After examining Spencer’s discovery, Laurence Marshall’s boundless imagination foresaw a complete revolution in furnishing cooked food, piping hot, to large volumes of people. He could visualize central kitchens where food could be cooked to the edge of completion in minutes, transported to satellite locations, heated to completion in seconds, and served to a rushed and busy world in a tempo that fit its needs.

To put it all another way, Marshall got it right away, and he knew that this invention was likely to reshape the relationships we had with food forever.

Radarange Ad

The Radarange line was pitched to restaurants long before it hit homes. (jbcurio/Flickr)

Soon enough, he had engineers turn Spencer’s invention into a device that could make sense in commercial settings. (It was called Radarange, a combination of the radar-based technology that inspired the discovery and the word range, to suggest cooking.) The device was huge, nowhere near the diminutive scale of the device sitting on your kitchen counter.

It took another decade to get a version of the science oven that made sense in the average home, but once we did get it, it reshaped diets forever, for better and for worse.

“By the time Spencer turned from his proximity fuse work to concentrate on the magnetron, he had already made enough contributions to the state of the art to have achieved a formidable reputation in any university, but he was not a man with a university background. At an earlier period that would not have made a difference, but by 1940 the scientific community had moved to very high academic levels, heights which few nonuniversity men could attain.”

— A passage from The Creative Ordeal: The Story of Raytheon, noting what was perhaps the most stunning aspect of Spencer’s success developing magnetron technology—he didn’t have an academic background. Instead, he earned his reputation as an expert in optimizing microwave technology, and as one of Raytheon’s best engineers, almost entirely in the field. Before his death in 1970, Spencer worked his way up to senior vice president and a board member at the company.

Raytheon eventually handed the Radarange brand to Amana, a firm that actually specializes in kitchen appliances—and a company that Raytheon at one point owned. Barbara Hale, best known for Perry Mason, was the primary spokesperson during this period.

Five interesting facts about microwaves as they hit the home

  1. The first home microwave was an absolute flop. The Tappan Model RL-1, a model codeveloped by Raytheon, cost an eye-watering $1,295 upon its 1955 release. (That’s $14,835 in today’s money.) It sold just 34 units in its first year, and less than 1,500 over a nine-year period. It was an expensive luxury in its early days.
  2. The microwave hit its stride in the mid-1970s. The slow early sales of the microwave gave way to fast uptake starting in the mid-1970s, as prices came down. Eventually, it would become a device as common as a television set: By the 1990s, more than 90 percent of American homes had one—most assuredly helped by the fact that microwaves could be had for less than $100. Sales have dipped from time to time, but it’s likely because everyone already has one.
  3. A microwave works like a faraday cage. It’s not quite strong enough to block all electromagnetic signals, but the metal interior is designed to limit microwave signals from getting out, just like a faraday cage. But the door is the weak point of the equation—and if the door is damaged, it can cause potential leakage issues. Curious to learn more? I recommend this clip from Physics Girl that tests whether a microwave is strong enough to block wireless signals from a cell phone.
  4. The microwave turntable was a device someone invented. One thing that many microwaves have today that they didn’t have during those early years was a turntable that spun the leftovers on your plate so it got a more complete reheat. This was not a feature built into the device but developed as an accessory by an outside company, Nordicware, starting in 1980. Sold as the Micro-Go-Round, it was essentially a wind-up spinner that could keep your food rotating for up to an hour.
  5. Repairing microwaves is usually not worth it, alas. With the devices usually selling in the $50-$300 range, microwave repair often costs about as much or more than the device itself, according to Fixr. If you’re feeling brave, iFixit has a user-contributed guide on how to do it.

Steak Microwave

No stop what are you doing steaks don’t go in microwaves

It took us a while to figure out how to cook using a microwave

One of the things I find fascinating about how the microwave oven was originally sold was that it was pitched as a way to cook things that most people would not be caught dead cooking.

One early article about a commercial variant of the device, dating to 1947, suggests that it was used at the Heublein Hotel in Hartford, Connecticut, to specifically cook two kinds of foods that most modern cooks would definitely find offensive:

Now, just 50 seconds after the order has been placed in the kitchen the steak is done to a sizzling brown, ready to serve. A lobster takes a little longer, one and one-half minutes to cook completely, while broiled chicken remains in the Heublein stove two minutes.

Mind you, if you look around, you can find some defenders of cooking lobster and steak using a microwave. But certainly, it was not exactly a perfect fit for this new model of cooking.

(Yes, Spencer tried lobster. He even patented it.)

The problem with the microwave, as anyone who has ever reheated a burrito in one assuredly knows, is that it has different cooking qualities from a traditional ovens. This can be a good thing in some cases—many have benefited from the microwave’s sheer speed in melting cheese, for example—but some foods just don’t work very well. The egg, an early food that Percy Spencer tested, is an excellent example.

Better-fitting, more-processed foods would eventually come, but they needed to be developed. (I’ve written about some of them, including frozen pizza and Hot Pockets. Admittedly, frozen pizza usually goes over better in an oven.) And oddly enough, it was one of the first foods that Percy Spencer tested that turned out to be the true breakthrough hit.

Microwave popcorn was the solution to making a popular food easy to serve. Popcorn is an annoying food to manage through traditional means thanks to its reliance on oil, and tough to cook easily on a stove, making it a sometimes food largely eaten outside the home, despite its popular appeal. But microwaves, combined with a little food science, solved this problem by making it a food that worked significantly more conveniently in a bag you put in a microwave for three minutes.

Percy Spencer Popcorn

Percy Spencer knew popcorn would make this thing pop, apparently. (Google Patents)

Spencer took a stab at it himself in the 1940s—literally putting a cob of corn in a bag—but it took a few decades for the effort to re-emerge in the arms of the food industry.

With the modern form first developed by the Pillsbury company, with patent applications filed around 1972 (for the buttery coating) and 1973 (for the bag), the kernel of the idea ended up dominating over the market by the mid-1980s, generating $160 million in sales by 1985—all the more impressive, given that microwave popcorn was only test-marketed six years earlier.

So, what took so long to get popcorn on the market? Turns out that just putting tiny kernels of corn into a microwave is a bad idea, which is why all this food science work needed to be put in to come up with a solid concoction that could expand as necessary. Even Pillsbury’s early recipe was imperfect, thanks to its reliance on coconut oil, requiring freezing. But eventually, the food industry figured it out and developed the microwave’s killer app.

Other types of food also saw innovation around this period—efforts to improve the quality of breaded foods, for example, led to the invention of microwave susceptors, made of a metallic plastic that helped add a little crisp to a type of food that infamously does not handle microwaving particularly well. For years, it led to innovation in the food aisles—and some would argue, a fresh reliance on preservatives, and a decline in the overall quality of cooking. It was hard to argue with the benefits when you looked at a food like microwave popcorn, so clearly a match of format and use case.

Now, some will be critical of the status of the microwave in the modern day—it’s not a universally loved device even in my own household—but the fact of the matter is, it created innovations that we’ve been able to leverage since, all thanks to a little observation and a whole lot of food science.

“But the way the FDA sees it, the revolutionary techniques producing these niceties were applied before the agency’s regulations were ready for them.”

— A passage from “Keeping Up With the Microwave Revolution,” a 1990 document published by the Food and Drug Administration discussing the safety of the microwave in the wake of the innovations it has enabled in food production. One of the biggest problems is that the FDA did not put in place regulations for temperature—which turned out to be a problem when microwaves began generating heat at levels upwards of 500 degrees Fahrenheit with the use of microwave susceptors.

Like many inventions that reshaped society in the latter half of the 20th century, the microwave came as a byproduct of work developed in wartime that was then brought to a consumer context.

The benefits of these kinds of innovations vary greatly, as game-changing as modern-day computers and as modestly useful as instant mashed potatoes. Even video games, GPS, and WD-40 have a lineage in defense contracting.

It can feel strange to consider that there was a point in our history where all the good innovations were coming not from random dudes in a garage, but defense contractors with goals to help us fight big battles.

As that quick 10-second meal you make is spinning around on the turntable buried inside your microwave, it can feel a little weird to consider that so many things we rely on just to get by exist because some company was trying to help the U.S. government win a battle somewhere.

Raytheon is a gigantic company these days, arguably bigger in scale than the microwave that was invented under its roof. It is controversial—when Girls Who Code teamed up with them about a year ago, it became a whole thing, just as one example.

We live in a society underpinned by innovations like these—and it’s weird to consider the ethical questions that come with them sometimes.

I think we can agree that the microwave was a net good for society, even if you probably would never eat a steak heated by one. But why do I feel a tinge of guilt about it, knowing where it came from?


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Ernie Smith

Your time was just wasted by Ernie Smith

Ernie Smith is the editor of Tedium, and an active internet snarker. Between his many internet side projects, he finds time to hang out with his wife Cat, who's funnier than he is.

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