The entire technology of radar, which is the ability to use radio waves to detect objects at a distance, was barely invented at the start of the war but became highly developed in just a few years at sites like the"Radiation Laboratory" at MIT. By allowing people to"see" remotely, at very long distances, radar made the idea of"surprise attack" virtually obsolete and vastly enlarged the arena of modern warfare(today's radars can see potential attackers from thousands of miles away). Radar allowed nations to track incoming air attacks, guided bombers to their targets, and directed anti-aircraft guns toward airplanes flying high above Researchers not only constructed the radars, but also devised countermeasures: during their bombing raids, Allied bombers dropped thousands of tiny strips of tinfo code-named"window" and"chaff" to jam enemy radar