Invention of the microwave oven

Jules Henri Giffard Airships are lighter-than-air flying crafts that propel through the air with thrust mechanisms, such as propellers and rudders. The first passenger airship was built in and designed by Jules Henri Giffard.

Invention of the microwave oven

The type of radiation emitted by microwave ovens is non-ionizing. Outside of potential burn risks, experiments done with rodents have yet to show any major adverse effect to prolonged exposure to microwaves at the 2. Spencer himself, despite being literally surrounded by intense microwaves for much of his life, lived to the ripe old age of 76, dying apparently of natural causes.

During WWII, Spencer managed to increase production of radar sets for the military from per day to per day using the same number of workers. He did so by designing a machine that could more or less mass produce the magnetrons in the radar set.

The machine worked by stamping thin cross sections of tube out of silver-solder and copper. The cross sections would then be piled on one another in a specific fashion and then cooked on a conveyer belt oven. They would then meld together to form the finished magnetron tube.

The previous best known method for developing these same tubes was to machine them out of solid metal, which was a much more time consuming and resource wasteful process. Along with figuring out a way to drastically increase production of the essential radar sets, Spencer also figured out several ways to make them drastically more sensitive.

For his work in this area, he was awarded the Distinguished Public Service Award, which is the highest award a civilian can receive from the U. Other awards and achievements, besides the Distinguished Public Service Award, Spencer achieved included: Not bad for a kid who in his early life was destined to work at a spool mill his whole life, until he changed his fate by self educating.

Microwaves actually heat from the outside in, very similar to other heating methods. You can read more about this here.


This creates microwaves in the oven that have nothing to absorb them. This standing wave is reflected back and forth within the microwave, between the tube and the cooking chamber, and will eventually burn out the magnetron. This same effect can occur when cooking dehydrated food or with food wrapped in some sort of metal where there is very little to absorb the emitted microwaves.

There is really nothing special about the material the window of your microwave is made of.

Invention of the microwave oven

What stops the microwaves from cooking you, instead of your food, is the metal mesh that is on the inside of that clear plastic or glass. At its core, a microwave oven is a pretty simple device.

This magnetron directs microwaves into a metal box. These generated microwaves then bounce around inside the microwave until they are absorbed via dielectric loss in various molecules resulting in the molecules heating up.

Matter that works well here are things such as water, ceramics, certain polymers, etc. These all end up converting microwave energy into heat quite effectively. More specifically, Microwave ovens work by having an internal magnetron emit electromagnetic waves around the frequency of 2.

Basically, molecules such as water molecules are electric dipoles. This means that they have a positive charge and a negative charge on opposite ends. Thus, they will rotate themselves rapidly when trying to align themselves with the alternating electric field from the microwaves.

As these molecules rub against each other, they heat up and, as they do so, they themselves also become part of the cooking process, heating up molecules around them that may not be absorbing much, or any, of the microwaves.After the war, the fact that the Gem style paperclip had served as a symbol of unity resulted in interest in the origin of the paperclip, at which point the article written by the patent agency worker and the subsequent patent by Vaaler, who was now long dead, was discovered.


In general, for microwave cooking or heating, it’s better to use a ceramic plate or glassware and, to cover, paper toweling or another ceramic plate. Today I found out the microwave oven was invented by accident by a man who was orphaned and never finished grammar school.

The man was Percy Spencer.


At the age of just 18 months old, Spencer’s father died and his mother soon left him to his aunt and uncle. His uncle then died when Spencer was. Aug 12,  · Popcorn in the bush, anyone?

A Woolies lasagna, perhaps? All of these basic human requirements are now available to you, thanks to probably the greatest invention ever.

A 12V Travel Microwave Oven. Antisepsis.

Invention of the microwave oven

Joseph Lister, Professor of surgery at Glasgow University, was the first to realize that the high post-operative mortality of his patients was due to the onset of . Microwave Oven 10 Greatest Technological Inventions (3/12)Though humankind got along just fine without microwaves before they were developed in the late s, the invention has been a .

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