What Is the Difference Between a Microwave & an Oven?

How Ovens Work

• An oven is an appliance with an enclosed space that uses indirect heat to cook food. Modern ovens generally use electricity or natural gas to produce heat. Electric ovens rely on the tendency of materials to get hot when an electric current is run through them, a principle called resistance. Metal elements are placed on the top and bottom of the oven and an electric current is run through them. Gas ovens burn natural gas to produce the heat needed to cook food. A thermostat measures the temperature in the oven and adjusts the current or gas flow to keep the temperature at the desired setting.

Convection and Conventional Ovens

• Conventional ovens rely on radiant heat of electric elements or gas burners to heat the oven enclosure. Convection ovens also have a fan inside the oven to circulate the air inside the oven. This causes things in the oven to cook more evenly and quickly. Convection ovens are commonly found in commercial applications and are more expensive than conventional ovens.

Microwaves

• Microwaves are a type of electromagnetic energy that travel at the speed of light. They have a short wavelength, around 2450 megahertz. This frequency is below that of the visible light spectrum and just above that range of frequencies used for radio and television broadcasts. They are a non-ionizing type of energy, which means they are not damaging in the same way as radioactive radiation.

How Microwave Ovens Work

• A microwave oven works by using a type of vacuum tube called a magnetron, a complicated electric device that generates microwaves of the proper frequency and aims these rays into an enclosed space where they are absorbed by the food. As the microwaves are absorbed, the molecules in the food, particularly water, vibrate faster, causing friction, which produces heat and cooks the food. This type of cooking is very efficient for heating certain foods, but not good for processes like baking or cooking techniques which require browning of food.

History of the Microwave Oven

• The microwave oven is the product of an accidental discovery. In 1946, Dr. Percy Spencer was conducting experiments with a magnetron and a candy bar in his pocket melted during the experiment. He put some popcorn and an egg near the apparatus and the corn popped and the egg exploded. He built a metal box into which the microwave energy could be directed and food placed in it cooked very rapidly. By the end of the year, the first patent on the idea of microwaves used to cook food was filed by his employer, the Raytheon company, and by 1947, the first commercial microwave oven was available. It was 5 1/2 feet tall, weighed about 750 pounds and cost $5000. Today, in 2010 a basic home model microwave oven can be had for under $50.