Shocking!

May 31, 2016 4:12 AM

Lightning strikes at 7000 frames per second. [SLYT]
posted by Mitheral (16 comments total)

I suddenly want to play Missile Command.
posted by AlonzoMosleyFBI at 4:24 AM on May 31, 2016 [9 favorites]

But, but, every pedantic asshole knows lightning actually goes from the ground to the sky! You can't be posting things like this that demonstrate that argument is both incomplete and ultimately meaningless!
posted by Mr.Encyclopedia at 5:23 AM on May 31, 2016

I'm unsure why the video seems so choppy. Is that just bad slowmo-ing on the part of whoever made it? Or is lightning actually kind of jumpy, even at 7000 frames per second?
posted by jacquilynne at 5:42 AM on May 31, 2016

Actually YouTube maxes out at 60 frames per second. If this were actually playing at 7000 frames per second the lighting strikes would appear instantaneous.
posted by snofoam at 5:51 AM on May 31, 2016 [2 favorites]

Ah, I get now why getting struck by lighting is such a concern. It's sending out all those feelers, basically looking for the first conducter it can find.
posted by mantecol at 6:07 AM on May 31, 2016 [2 favorites]

Amazing how the final strike is still practically instantaneous (and completely overwhelming). (Is the final strike going up or down? Can't really tell...)

Looks like they're playing back at about 2 fps. So to get smooth (24 fps) slow-motion playback at this speed, I'm guessing they'd have to record at closer to 84,000 fps.
posted by clawsoon at 6:08 AM on May 31, 2016

I'm unsure why the video seems so choppy.

I think the YouTube video is playing the video that was recorded at 7000 fps at 2 fps or whatever--those jumps are the individual frames.
posted by jjwiseman at 6:09 AM on May 31, 2016 [1 favorite]

I'm unsure why the video seems so choppy.
This Maine state webpage says that the leader (the down-stroke) travels at around 320,000 feet per second. At 7000fps, the lightning travels 45.7 feet between frames.
posted by MtDewd at 6:10 AM on May 31, 2016 [7 favorites]

It sounds different than I expected.
posted by roger ackroyd at 8:05 AM on May 31, 2016 [2 favorites]

sheeeewwwwwwffffffBOOOOOOOMMMMMMshshshshs
posted by rebent at 8:17 AM on May 31, 2016 [1 favorite]

From a similar video here, here's a good explanation of what you're actually seeing here and why there is a sudden flash after one of the branches hits the ground "a suddenly appearing positive spike moving up from the ground " :

The above lightning bolt starts with many simultaneously creating ionized channels branching out from an negatively charged pool of electrons and ions that has somehow been created by drafts and collisions in a rain cloud. About 0.015 seconds after appearing — which takes about 3 seconds in the above time-lapse video — one of the meandering charge leaders makes contact with a suddenly appearing positive spike moving up from the ground and an ionized channel of air is created that instantly acts like a wire. Immediately afterwards, this hot channel pulses with a tremendous amount of charges shooting back and forth between the cloud and the ground, creating a dangerous explosion that is later heard as thunder. Much remains unknown about lightning, however, including details of the mechanism that separates charges.
posted by beagle at 11:18 AM on May 31, 2016 [6 favorites]

Beagle's video is more what I would have expected -- the motion of the tendrils of lightning are more fluid and less choppy. It seems like the frames chosen to display are from a bunch with a large break between them, rather than having been chosen at even intervals from throughout the original clip.
posted by jacquilynne at 12:06 PM on May 31, 2016

To see the effect in really slow motion, check out the 15,000 Volts in Wood video.
posted by clawsoon at 12:10 PM on May 31, 2016 [1 favorite]

To see the effect in really slow motion...

For added confusion, that video appears to be stop motion/sped up. :)
posted by jjwiseman at 12:42 PM on May 31, 2016 [1 favorite]

Stop motion, but cool nonetheless.
Has anyone posted a large-scale image of the known universe and pointed out how it looks like a brain yet? Cos that feels due.
posted by quinndexter at 12:42 AM on June 1, 2016

Wow. I now believe in Zeus.
posted by hoist with his own pet aardvark at 12:08 PM on June 1, 2016