While several nations were developing similar technology, Sir Robert Watson-Watt is credited with developing the first practical radar system for detecting aircraft. Radar works by emitting radio waves and measuring the time it takes for them to bounce off an object and return. This invention was a decisive factor in the Battle of Britain during WWII, allowing the Royal Air Force to intercept German bombers before they reached their targets. Beyond warfare, radar revolutionized civilian life by making air travel and maritime navigation significantly safer, especially in fog or darkness. It is the basis for modern weather forecasting (Doppler radar), speed enforcement by police, and even the sensors used in modern autonomous vehicles. Radar proved that electromagnetic waves could be used not just for communication, but for high-precision environmental mapping.