Plasma arc - GIF

[ToolTalkBot]

Plasma arc.




Previously:

Cesium plasma - GIF
Plasma in slow motion - GIF
Sodium plasma - GIF

[hemmjo]

what would make that happen? Maybe moist, salty air? Or perhaps, but unlikely, downed high voltage lines somehow energized those lower voltage lines?

[Hoosiersmoker]

Looks like the ghost of a linesperson traveling down the lines. Happy Hallowe'en!

[Karl_H]

She watches it for 20 seconds, until it is 3 or 4 houses down the road. Then it is urgent to "get inside!"

[BuffaloJohn]

what would make that happen? Maybe moist, salty air? Or perhaps, but unlikely, downed high voltage lines somehow energized those lower voltage lines?

Probably a lightning strike and a cascade of arresting devices failing (or completely missing). The air is humid (notice all the flooding). Salty air, maybe, but we can't tell from the video.

We - as high school students in the early 70's - used neon sign transformers to make a Jacob’s ladder. If you have enough voltage, you get the air between the conductors to ionize and the arc is formed from the high voltage and the ions. It needs to be alternating current so that the arc can sustain itself. If it is just direct current, you can get repeated sparking, but if the arc is sustained for too long - it becomes welding and the electrodes melt.

Also, to step up the voltage, you need alternating current - transformers don't work on direct current. Well, this power line is AC and is much higher than the voltage entering the house.

BTW, this is the principle behind florescent lights just more controlled. You probably don'r want anyone saying "oh, my god" multiple times when you turn the kitchen lights on...