Acoustic mirrors are bizarre, monolith-like structures once used to detect incoming aircraft. Their usefulness was cut short as they were replaced by the radar. Today, we have a look at what remains of the once-vast network. Join this channel for exclusive videos: https://www.youtube.com/channel/UCzIZ8HrzDgc-pNQDUG6avBA/join Chapters: 00:00 - What are acoustic mirrors? 00:37 - The history of acoustic reflection technology 03:00 - Development of the acoustic mirror 06:57 - The early forms of Rada