What Are Microwaves?

Microwaves are electromagnetic waves that transmit energy by a process called resonance. When microwaves come into contact with water, fat or other substances, they absorb the energy and convert it to heat. This is what cooks food and makes a cup of coffee, for example. Microwave ovens are popular because they provide quick, convenient meals. They can help prevent the growth of harmful bacteria that may cause food poisoning, and they reduce the amount of energy required to boil water or heat a meal. The microwaves also heat food evenly, making it less likely to burn or overcook.

Unlike lower frequency radio waves that can reflect off the ionosphere or follow the contour of the Earth, microwaves only travel by line-of-sight paths. They are also absorbed by moisture in the atmosphere, which can limit the range of communication links at high frequencies (a phenomenon known as rain fade).

While microwaves can make metals hot, they do not penetrate human skin. However, repeated exposure to high-intensity microwave radiation can damage the lenses of the eyes and may cause cataracts.

While some people have criticized microwaves for encouraging the consumption of unhealthy ready-made meals, the fact is that the technology has many uses in the home. Microwaves can quickly reheat leftovers, and they are great for heating up pre-cooked packaged foods and instant rice. Microwaves are also an efficient way to heat up beverages, such as tea and coffee, or to re-heat milk for babies.