While it’s possible that there are multiple phenomena behind things grouped up as ball lighting, there was a theory that it was basically the result of a lightning strike hitting the ground, vaporizing certain substances, and then the cloud of resulting gas rising and reacting momentarily while in the air.

A couple years back, there was some Chinese group studying lightning — not ball lightning — with some high-speed cameras and a spectrometer, and they got lucky and had one show up in their footage. The spectrogram showed that it was consistent with the “vaporized stuff from a strike on the ground” theory.

kagis

https://www.newscientist.com/article/dn24886-natural-ball-lightning-probed-for-the-first-time/

Natural ball lightning probed for the first time

The spectrograph revealed that the main elements in the ball were the same as those found in the soil: silicon, iron and calcium. The observations support a theory for making ball lightning put forth in 2000 by John Abrahamson at the University of Canterbury in New Zealand.

Abrahamson surmised that when lightning hits the ground, the sudden, intense heat can vaporise silicon oxide in the dirt, and a shockwave blows the gas up into the air. If there’s also carbon in the soil, perhaps from dead leaves or tree roots, it will steal oxygen from the silicon oxide, leaving a bundle of pure silicon vapour. But the planet’s oxygen-rich atmosphere rapidly re-oxidises the hot ball of gas, and this reaction makes the orb glow briefly.

The theory garnered support in 2006, when scientists at Tel Aviv University in Israel were able to create ball lightning in the lab by firing mock lightning at sheets of silicon oxide. The event in China marks the first time such an orb has been captured in nature with scientific instruments.

But I don’t think that what the footage shows is likely a cloud of gas reacting. It didn’t look like a bolt, and in the footage I saw, was just slowly rising. And it didn’t last very long, either.