Microwaves in the Kitchen

The microwave is a type of electromagnetic radiation that has wavelengths between 1 and 1000 GHz. It is used to transmit thermal energy and cook food, among other things. It is reflected by metal, passes through glass and paper and is absorbed by food. The term has also a more technical meaning in electromagnetics and circuit theory: it refers to the behavior of electronic signals at low power levels.

The use of microwaves in the kitchen is a major part of their popularity, but they have many other uses too. They can be used to send analog and digital voice, data and television transmissions; they are the basis of radar (RAdio Detection and Ranging) for weather tracking and traffic control; they are used in industry to dry and cure wood products, rubber and resins and make potato chips; and they are important to the military, where they are used for target practice and for detecting speeding submarines.

Microwaves are also a key part of the cosmic microwave background radiation that is studied to help scientists understand the Big Bang. They are naturally emitted by stars, including the Sun, and they can be detected with large dish antennas, such as the Atacama Large Millimeter Array in Chile.

In the kitchen, microwave ovens are a convenient way to prepare meals, heat leftovers and defrost meat quickly without subjecting it to dry air, as would happen in a conventional oven. They can also “steam” foods, and they can be used to reheat beverages. However, microwaves have their disadvantages: They can sometimes produce uneven heating, and they can cause plastic utensils to melt. This may pose a health risk, as some plastics contain the potentially harmful additives bisphenol A and phthalates.