Microwave is a type of electromagnetic radiation, usually in the radio frequency range (31 – 1000 GHz). The term microwave is also used to describe the heating of materials using a microwave oven. Microwave heating is typically faster than heat conduction or convection, and may provide energy efficiency advantages over other methods.
The microwaves in the oven are emitted from a magnetron that oscillates to produce electromagnetic waves. When these microwaves hit the food, they cause water molecules in the food to vibrate and heat up. As the microwaves move around the food, they heat it evenly. The food is ready to be eaten in a very short time. Because it is so fast, microwave cooking can be helpful for people on a tight schedule.
Because of the speed at which microwaves heat food, they also preserve more nutrients than other cooking methods. This is because foods aren’t exposed to high temperatures for long periods of time, as they would be in conventional ovens.
In addition to the home use of microwave ovens, they are also used for industrial purposes such as warming plastic rods prior to extrusion and to kill cancer cells in research labs (microwave hyperthermy). Microwave radiation is also used in radar applications and by communications satellites to relay telephone calls and television broadcasts between cities.
Microwaves are not as effective at killing bacteria and other pathogens that could lead to food poisoning as other cooking methods, such as boiling or steaming. This is particularly true for liquids like soup and broth, which can boil over or explode if they are heated too quickly.