Random trivia that the lowest frequency electromagnetic waves we have measured are known as Schumann resonances and are around 8 Hz and are generated by the lightning strikes that are always happening *somewhere* on the planet!
and then I'm writing about HIGH-ENERGY GAMMA RAYS produced by lightning
I like to think they're named for Clara and Robert Schumann. Wikipedia tells me that pipe organs can play notes down to 8 Hz.
If you like this fact, you might also like that the ocean is detectable on seismometers anywhere in the world. Even in the furthest inland places, the ground is shaking just a little tiny bit from wave action in the ocean.
This is part of how passive source magneto-telluric studies work. More or less equivalent to the ambient "noise" sources that make some types of surface wave seismic tomography work.
Ok but how can I generate one of these with consumer electronic/music production gear?
I wonder how this affects animals that communicate down there?
There’s telluric currents underground too.
They are not quite the lowest EM frequencies we measure though - variations in the solar wind create much lower frequencies, much loved by deep-earth geophysicists! sites.ualberta.ca/~unsworth/MT...
An undergrad poster I made nearly 30 years ago had the grand title "In quest for the Schumann Resonances" - my MT coils duly picked them up!
Now that's interesting! There have been a few studies linking infrasound that infrasound to feelings similar to those reported with paranormal activity.