3 ms·

Yes, generally the smaller the wavelength, the worse the attenuation. Quick googling: 4g is 600Mhz to 2.5Ghz or 0.5m to 12.5cm wavelength. For comparison, the

Yes, generally the smaller the wavelength, the worse the attenuation. Quick googling: 4g is 600Mhz to 2.5Ghz or 0.5m to 12.5cm wavelength. For comparison, the US Navy uses 80Hz or 3750km wavelength to talk to submerged submarines.[1] [1] https://en.wikipedia.org/wiki/Ground_dipole https://en.wikipedia.org/wiki/Ground_dipole

zepearl 5y ago
From https://en.wikipedia.org/wiki/Ground_dipole https://en.wikipedia.org/wiki/Ground_dipole : > After initially considering several larger systems (Project Sanguine), the U.S. Navy constructed two ELF transmitter facilities... > Both transmitters were shut down in 2004. The official Navy explanation was that advances in VLF communication systems had made them unnecessary. I then started reading about VLF https://en.wikipedia.org/wiki/Very_low_frequency https://en.wikipedia.org/wiki/Very_low_frequency and on that page I see this sentence: > VLF waves used to communicate with submarines have created an artificial bubble around the Earth that can protect it from solar flares and coronal mass ejections; this occurred through interaction with high-energy radiation particles. That sounds absolutely weird - how should that "...that can protect it from solar flares..." be interpreted? EDIT: didn't notice Wikipedia's linked article - https://www.theatlantic.com/science/archive/2017/05/wow-guys/527193/ https://www.theatlantic.com/science/archive/2017/05/wow-guys...