I’ve found myself explaining that to people a few times. Lower frequencies are also used to communicate with submarines since they propagate better through wate

I’ve found myself explaining that to people a few times. Lower frequencies are also used to communicate with submarines since they propagate better through water. I’m guessing that when radio first came out frequencies were lower, though I don’t have any facts there. “Shortwave radio” is another one that’s confusing term these days for the same reason.