China builds massive radio antenna facility

The video discusses a radio antenna covering 3700 square kilometers, as reported by the South China Morning Post. This antenna can emit extremely low frequency (ELF) radio waves ranging from 0.1 to 300 Hertz. These waves can be detected by Chinese military submarines deep in the ocean. Additionally, the antenna has potential applications in detecting earthquakes and minerals.

What new insight or understanding did you gain from this video?