Microwave Oven

Most people think that the microwave oven nowadays is a pretty old invention, but there are probably a lot of people that would be wrong when guessing when it actually was invented. An engineer named Percy Spencer was working on an active radar when he suddenly discovered that the candy bar in his pocket was melting. He understood that it somehow was connected with the microwaves from the magnetrons and began to research the phenomena. This was in 1945 and two years later Percy Spencer had a prototype working, which he patented. The prototype was in the size of a large closet and mustered three times the radiation found in modern microwave ovens. As the years went by the microwave oven shrunk in size, got more effective and began to be used in industries and high quality kitchens. The microwave oven did not become cheap and easy enough to be bought by the ordinary man until the late 80s and that is when the microwave oven boom spread across the globe, resulting in that the microwave oven today is a standard household appliance everywhere.

The microwaves that a microwave oven creates have some very special properties. Unlike many other waves of radiation the microwaves can set certain molecules in motion, making them to crash into other molecules and thusly through sheer friction create heat within the food product itself. The microwave oven uses the fact that water molecules among many other molecules are electric dipoles, meaning that they are not perfectly balanced when it comes to electrical charge having one negative side and one positive one. Microwaves are not perfect when warming food although many seem to think so. Heating frozen products is much more difficult than heating liquid water which means that frozen products could be boiling in the edges while still frozen in the middle. Also, spreading the heat evenly is an enormous problem when working a microwave oven. The rotating dish inside the microwave has been invented to help with this problem but most people have misunderstood its usage rendering it almost useless. To get an as even spread of microwaves as possible should the food be placed slightly off centre on the rotating dish and not in the centre as many believe. Otherwise the food will not actually move but just rotate around its own corner.