There's a reason that scuba divers use sign language and that caves and tunnels create radio dead zones. The laws of physics prevent radio signals from penetrating materials like water, soil and stone, and that's been a frustrating limitation of mode...
This four-inch antenna could let you text from deep underground
There's a reason that scuba divers use sign language and that caves and tunnels create radio dead zones. The laws of physics prevent radio signals from penetrating materials like water, soil and stone, and that's been a frustrating limitation of mode...
The Earth's atmosphere bears precious little resemblance to what it looked like at the start of the Industrial Revolution. As radio technology has advanced and spread, the signals that transmitters produce -- specifically the Very Low Frequency (VLF)...