Communication, Physics, Innovation
The radio spectrum is enormous, with millions of different channels. It isn't dependent on the phone lines or the internet, and is in many ways the "wild west" of communication. Amateur radio (also known as ham radio) enthusiasts explore this unseen frontier, connecting to each other around the world. Part of the appeal of amateur radio is the freedom of it. If you build your rig, that's your channel and broadcast. Nobody can stop you from spreading whatever message you want, though whether or not people tune in and listen is up to them. With the internet connecting the world like never before, amateur radio may seem antiquated, but its reliability cannot be understated.