August 8, 2008
Slow motion lightning
Slow motion lightning
This explanation comes from Lenski the comments section of the Huffington Post where I found the video:
The search for a path proceeds through the treelike process that shows early in the video, finding the thin trails that are of somewhat lower resistance than clear air. Basically, a slightly higher density dust particles or raindrops allows enough current to flow to keep looking for more path. These tendrils of ionization last a little while, long enough to present a temptingly lower resistance for the main strike. It’s a race to see which one completes the circuit first.
Once a path between the sky and ground has been found, that’s when the action really kicks in: A surge of current flows through the slightly lower resistance pathway, blasting the outer electrons from the atoms of atmosphere in its path forming a plasma arc. The dramatically lower resistance causes it to continue passing the surge current. The electrons stripped from the atoms of the atmosphere are “free electrons” that carry the current until the lightning strike dissipates the electrical charge that started the whole process in the first place.
Here’s something that was only discovered recently: Lightning strikes are such high energy events that they produce x-rays! (It makes sense, once we think about it… The process of stripping electrons away from the atoms of the atmosphere and subsequent recovery of the electron shells as the event ends would produce electromagnetic radiation, at energy levels all the way into x-rays.)
