Splitting ions in the ether

August 4, 2007 7:23 AM

What happened last night? My friend and I were sitting in my apartment living room, lights on, not intoxicated, during a thunderstorm, which seemed to be nearby but not directly over us. Suddenly there was a spark in the air -- literally, in the middle of the room.

It was a pinpoint of white light that appeared for a fraction of a second, accompanied by an audible snap. About five minutes later it happened again, in a spot maybe eight feet from the first one. There were no accompanying phenomena either time: no smell of ozone, no hair standing on end. The lights didn't flicker; the cats were unfazed.

What happened? I've googled ball lightning and ghost lights and sparks house -kimono -steak but no standard phenomenon seems to quite match the description. Do I need to start looking for a supernatural explanation?

posted by Eater to science & nature (15 answers total)

Barring a little voice imploring Carol Anne not to go into the light, it's most likely physical. I narrowly missed witnessing one of these events. During a thunderstorm, I exited a room, only to hear a loud snap behind me. When I rushed back into the room, the monitor there was in need of some serious degaussing. No ozone smell.

I once waited about half an hour for a professor to show up for a final exam during a storm. When he appeared finally, he was visibly white and shaken. A spark like the one you mentioned left his wall socket, went right past him, and then entered the floppy drive on his PC.

Lightning is weird and unpredictable. Then, when you're in a big metal cage that isn't completely connected, well, stuff happens.
posted by adipocere at 7:38 AM on August 4, 2007 [1 favorite]

So how is this different from ball lightning? That was my first thought.
posted by Sfving at 7:48 AM on August 4, 2007

Weird shit happens routinely without needing explanation by supernatural causes.

I find your ball lightning hypothesis plausible. It seems that if an unstable, highly energetic phenomenon occurs sometimes for a few seconds, it can also last merely a few milliseconds. Furthermore, the wikipedia page on ball lightning mentions that there're theories and descriptions that do not include the sort of gross electrical effect that would cause the lights to flicker. If it was pin-point size, you'd probably not notice any ozone produced.

On preview: adipocere might be on to something. Atypical interior lightning.
posted by Netzapper at 7:52 AM on August 4, 2007

Same thing has happened to me - a bolt of lightning came out of the kitchen's fluorescent light fitting and sparked into the floor, not 2 feet away from me.

This was during a thunderstorm too.
posted by the cuban at 7:55 AM on August 4, 2007

What I saw occurred quite a distance from the nearest electrical appliance or light fixture, incidentally, unlike adipocere's anecdotes. And all the descriptions of ball lightning I'm finding have it existing for several seconds, and traveling through the air. It'd be nice to see a description that more closely correlates with what I saw.
posted by Eater at 8:19 AM on August 4, 2007

How positive are you that this was actually inside your house. Could there have been lightning close outside and you saw a reflection/glint off something else?

Barring that, I agree with the ball lightning guess.
posted by jpdoane at 9:05 AM on August 4, 2007

I'm confident it wasn't a reflection, since there were no reflective surfaces nearby and it was accompanied by a sound that was definitely inside the apartment.
posted by Eater at 9:58 AM on August 4, 2007

It definitely sounds like ball lightning!

It's pretty well-documented, but completely mysterious.. I'm totally jealous. :)
posted by onanon at 11:09 AM on August 4, 2007

Is there an overhead fan in the room?
posted by jwells at 11:37 AM on August 4, 2007

There's no fan. There's an overhead light but the sparks were nowhere near it. I guess ball lightning is the consensus. It was disappointingly un-ball-like though.
posted by Eater at 12:18 PM on August 4, 2007

Thank you for this very interesting account.

It would be nice to know whether your apartment is on the top floor of the building, and whether either the roof is metal or there're a lot of metal objects on the roof.

If the answer to both of those questions is yes, I'm inclined to think you witnessed dielectric breakdown of the air itself due to induced charge or charge separation on the metal of the roof:

Although air is normally an excellent insulator, when stressed by a sufficiently high voltage (an electric field strength of about 30 kV/cm [1]), air can begin to break down, becoming partially conductive. If the voltage is sufficiently high, complete electrical breakdown of the air will culminate in an electrical spark or arc that bridges the entire gap. While the small sparks generated by static electricity may barely be audible, larger sparks are often accompanied by a loud snap or bang.

If what I'm suggesting is true, the snaps and light you observed were probably part of the formation of a spark leader, since no completed discharge seems to have taken place.

It's worth noting that the storm was not not directly over you. The most intense and highest voltage (up to a gigavolt apparently) lightning bolts take place at the leading and trailing edges of storms; they are known as positive lightning and have polarity relationships the reverse of the usual.
posted by jamjam at 1:00 PM on August 4, 2007 [2 favorites]

That's very interesting, jamjam. I'm on the third floor of a six-floor building with a tar roof, but otherwise your explanation seems plausible.
posted by Eater at 2:07 PM on August 4, 2007

I once saw floating basketball sized sparks dance along the line of fence in my parents back pasture early one morning - 4am. There was some morning fog and thunderclouds departing from the night before. You could hear them fizz, pop, and moan as the fog blew over the fence. They glowed enough to light up the trees on the other side of the fence line. My mom called it St. Elmos fire.
posted by tkchrist at 5:30 PM on August 4, 2007

Yeah, the electric field lines don't necessarily follow the rain. See cool photo. And I'm betting that spark leader tried a whole lot of different paths up and down your building, but its running through air instead of along pipes and things is certainly exceptional.
posted by eritain at 12:16 AM on August 5, 2007

Some kind of static maybe? My boy cat and I generate it regularly. Usually I get the zap but ocassionally I just hear it and he shoots me a dirty and injured look. I've never actually seen it though. That would be kinda neat.
posted by mu~ha~ha~ha~har at 10:39 AM on August 8, 2007