Radar, which stands for Radio, Detection, and Ranging, operates by sending out a pulse of radio waves and measuring how long it takes for the waves to bounce back after hitting an object—in this case, an aircraft. The time it takes for the echoes to return helps determine the distance to the plane.

In 2006, a team of U.S. and British scientists demonstrated the world's first working "invisibility cloak." The team, led by Sir John Pendry, created a small device 12cm across that redirects microwave...

The F-117 Nighthawk, known for its black coating and geometrical shape, is the first to use a radar absorbing material (RAM) and the "faceting" technique, both of which effectively made it invisible to radar. Renowned as the "Stealth Fighter", the F-117 was designed to sneak past strongly defended enemy territory and destroy targets of high value.