Microwave is a type of electromagnetic radiation that has been used for a variety of applications, from cooking food to sending data over long distances. In fact, much of the world’s data is transmitted by microwaves between satellites and ground stations.
The technology behind microwaves is based on the principle that water absorbs energy very efficiently, which is why most foods can be heated in a microwave oven. The radiation is produced by a small machine inside the microwave called a magnetron, which sends out waves at a specific frequency – typically 2.45 gigahertz.
Once the microwaves get inside the cooking cavity they bounce around until they hit something that can absorb them, such as a water molecule. This causes peaks (with lots of microwaves) and troughs (with few) which can cause uneven heating. This is why your microwave oven has a rotating dish in it, which ensures that all parts of the food are exposed to microwaves for an equal amount of time.
Many of the molecules in our food are electric dipoles, with one positive end and one negative. The alternating field generated by microwaves twists these dipoles back and forth, which creates energy. The resulting energy manifests as heat, which is what happens when you put a slice of pizza in the microwave. However, there is a risk that microwaves can cause damage to living tissues when they are absorbed at too high of a power density and for too long a period of time.