The internet is filled with things. Here are some of them.
All uninsulated lines show corona. [Corona discharge] just [is] not a big deal until you're dealing with a pretty high voltage. As the voltage goes from a very big positive to a very big negative, the air around it gets ionized... This is the normal mains hum... Water is much, much heavier than air, and it ionizes just as easily. So on a rainy or humid day, the corona is pulsing with water in it. This gives it momentum, so the heavier water particles travel out farther. But they themselves are ionized, which means they can ionize more air than the line could normally reach on its own, and ionized air is conductive. And there's almost always 3 of these lines pretty close together. The sound you're hearing is a million teeny tiny electrostatic discharges from all the charged up water particles interacting with each other with nearby lines or grounded objects. This is actually the worst time to be anywhere near them; the air is supposed to be their insulator, and at that moment it isn't working as well.
One popular theory is that ball lightning is caused when lightning striking the ground vaporizes some of the silicate minerals in soil. Carbon in the soil strips the silicates of oxygen through chemical reactions, creating a gas of energetic silicon atoms. These then recombine to form nanoparticles or filaments which, while still floating in air, react with oxygen, releasing heat and emitting the glow.
Advanced concepts in physics are notoriously hard to understand, taking smart people years to achieve mastery in even narrow fields.
But what if that was because all that years of accumulated physics knowledge and theory and experimentation and observation was wrong? What if, instead of the world of physicists such as Albert Einstein and Erwin Schrödinger and Paul Dirac and Max Planck being the foremost authority on the topics to which they've dedicated their lives, it was this retired electronics tinkerer slash photographer who was the true master? After all, if the so-called "physicists" were really experts on the topic, they'd have a website as awesome as this, which explains literally everything without even resorting to any of those pesky mathematical equations.