Microwave. The one household appliance almost everyone has in their home. Have you ever wanted to heat your meal quickly? Today, you can put it in a microwave and wait for only a few minutes but it wasn’t always like that. However, people did not always have this useful machine. The story of this useful machine began with radar, an engineer and a chocolate bar. During the Second World War, many engineers worked on better radar systems. Radar helped people find planes and ships from far away. These systems used a special machine called a magnetron. It produced an invisible type of energy called microwaves. At that time, engineers used these waves for radar, not for cooking. The microwave oven did not exist. Percy Spencer was an American engineer. He worked for a technology company and knew a lot about…