Microwaves are a form of electromagnetic radiation that emits energy from oscillating electric and magnetic fields. Microwave ovens use this radiation to heat food and liquids.
Microwave radiation is part of the radio frequency (RF) range of electromagnetic waves. Other RF frequencies include far infrared, terahertz radiation and ultra-high-frequency radio waves. These frequencies are used in communication systems for digital and analog voice, data and video transmissions, and radar equipment.
The prefix “micro” in microwave indicates the shorter wavelength of the radiation, compared to the radio waves and other types of electromagnetic waves previously used for communications. The first generators to produce microwaves were developed in 1920, and the etymology dictionary online cites the first usage of the term in English from 1931.
When microwaves pass through matter, the oscillating electric field causes the molecules in the material to rotate. As they rotate, they release the energy in the form of heat. This process, known as dielectric heating, is more effective in foods that contain water, such as fruits and vegetables, and less efficient in fats, oils and frozen foods.
The short cooking time of microwaves makes them a fast cooking option. This is especially helpful when you are in a rush, or don’t feel like spending a lot of time in the kitchen. However, there are a few drawbacks to microwaves: Food can be overcooked leading to dry and hard meals, and it is possible to accidentally burn yourself by touching hot dishes with your fingers or mouth. Additionally, microwaves can leak if the door is opened or damaged in some way.