A proximity fuze detects when its shell is close enough to the target and triggers the burst. This made a major difference to anti-aircraft gunfire. The idea had been discussed before World War II, although a working system arrived during the war. Radar offers a similar example of a concept that needed years of development before practical use. Discussing a technology did not mean that a navy already possessed an effective operational system.
Notable Point · 26:38-27:28
Proximity fuzes and the delay between concept and service
The idea of a shell that bursts near its target preceded the practical proximity fuze, illustrating the delay between invention and service.