I guess my only question is, why is this happening when there is literally no wind blowing?

Well, I can say definitively that I know what is making that clicking sound. It’s hard to see since the cable is in silhouette, but there are silver-colored spirals wound around the cable, and the sound is made by the plastic sheathing of the black cable wobbling inside of those metal spirals. The spirals are made of aluminum, I’m pretty sure. Those spirals are put there to stiffen the the hanging cable, and appear on the hanging cable between every set of poles (not just these, that are wiggling). There are two spirals mounted on each cable between the poles. I assume the spirals are mounted there to provide damping, just in case the wind does cause the cable hanging between the poles to swing too much. But, there was no wind blowing when I shot this video (Dec 5, 2023). The voice you hear is mine, just speculating on what might be causing the oscillating cable…

No, I’ve never tried to quantify the variables in that way. Just out walking the dog, and notice this strange behavior from time to time. I always assumed the poles were placed a specific distance apart, but honestly, I’m not sure. I suppose if I ever have the urge to pace it out to get a good estimate, I will…

Hmm. It’s odd that this isn’t ALWAYS vibrating, but it IS only between these two poles that I’ve noticed the vibration. But why not between other sets of poles? And since the cable vibrating the most isn’t a power cable (I believe it’s fiber, but it could be copper - but it’s definitely telecom, since it’s not insulated on the top crossbar, as the other power cables are), it can’t really be much power going through it. I’m kind of hoping someone else has seen similar behavior somewhere else. You can see the anti-wind-twist devices (don’t know what else to call them) bolted to the other telecom cable (sort of diamond-shaped) and they will cause the cable to stabilize when the wind is really blowing, but you can see the wind isn’t blowing at all, and the cable continues to vibrate quite noticeably. I really do hope someone else has seen something like it elsewhere…