Power surge video - why does the spark travel?

[Borek]

Any idea what is the physics behind? Why does the spark travel down the line?

 

[gmax137]

I miss 'ol Jim Hardy

Maybe @anorlunda

 

[berkeman]

Maybe the Lorentz force pushing clouds of short-circuiting ionized air away from the power source? (I'm not sure I have the direction correct, but I think it would be away...?)

 

[DaveE]

Maybe the Lorentz force pushing clouds of short-circuiting ionized air away from the power source? (I'm not sure I have the direction correct, but I think it would be away...?)

That's my guess. Like a rail gun! The direction is always to make the current loop area increase, to reduce the change in magnetic flux enclosed as the current increases. Lenz's law, I believe.

 

[256bits]

Is it a spark or combustion. I see what appears to be a smoke trail behind the flame.
Somewhat like line of gunpowder in the old westerns.

 

[anorlunda]

The title of the video said storm, so my guess is just plain old wind.

My firm used to do rocket triggered lightning experiments as shown in the picture. The parallel paths in the picture are repeated strokes. The total time duration is probably 0.3 seconds. The mechanism of horizontal movement is simply a trail of ionized air being blown by the wind.

In the case of the video below, we have continuous arc rather than separate strokes, but still there is a patch of ionized air being blown by the wind. Some of the ions get left behind, but new ones are created each instant.

In this video at 2:53-3:04 ask yourself why this arc wants to move to the left and why a long U rather than a shorter one. IMO, it is once again simply wind.

p.s. I miss Jim Hardy too. He was the best.

 

[gmax137]

oh that's a good video! Listen to Mom, at 3:15 saying "get in here!"

 

[berkeman]

oh that's a good video! Listen to Mom, at 3:15 saying "get in here!"

"Hey Darryl, grab your little brother Darryl and get your butts back inside!"

 

[Astronuc]

Maybe the Lorentz force pushing clouds of short-circuiting ionized air away from the power source? (I'm not sure I have the direction correct, but I think it would be away...?)

I was thinking IxB.

I was also wondering if it phase-to-phase and/or phase-to-neutral/ground.

 

[berkeman]

The title of the video said storm, so my guess is just plain old wind.

Aint no wind in those trees in the video...

 

[Astronuc]

oh that's a good video! Listen to Mom, at 3:15 saying "get in here!"

Good thing she didn't tell him to 'go fly a kite, and here's a key'.

 

[Keith_McClary]

trail of ionized air being blown by the wind.

Similar principle to a Jacob's Ladder?

 

[anorlunda]

Aint no wind in those trees in the video...

I'm not convinced. The arc in the video moved at about 10 m/s (20 knots). The trees had no leaves. 20 knots of wind does not make dramatic visible effects on bare trees. Wind is still my wager.

 

[nsaspook]

I'm not convinced. The arc in the video moved at about 10 m/s (20 knots). The trees had no leaves. 20 knots of wind does not make dramatic visible effects on bare trees. Wind is still my wager.

+1
https://www.kxan.com/news/stunning-...surge-traveling-down-power-line-during-storm/

The winter storm moving through the area is the same as the one knocking out power to cities in Texas and dropping snow from the Gulf of Mexico to the Ohio River Valley.

Easy to see the arc being affected by wind here causing wire slapping.

 

[DennisN]

Fascinating video, @Borek!
It's eerily beautiful with the different colors of the arc/spark.