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I was sitting in my bed using my computer. It was almost out of battery, so I got up and grabbed the charger to connect to the outlet. Then a strange thing happened: when my hand got near the outlet, a small lightning/spark came out of the outlet to my finger, and it shocked me. For my surprise, the shock was incredibly mild, similar to a static shock. Why did that happen?

I know that it is almost impossible for anyone to understand exactly why it happened with only this description, but I'm only looking for ideas of why that might have happened. Here are more details to help out: - The distance from the outlet to my finger when the shock happened was about 1 inch (thus, the lightning had a similar size). - It is a dry and very cold day (7 Fº, although I'm indoors). - I was using sweatpants. When I got to get the charger, my butt slid across the bed (maybe the friction charged me and what happened had something to do with static or something?) - I usually experience lots of static shocks in the room I was in. It has a carpet and metal door knobs.

Why did the lightning happen? Why was the shock so weak? And the fact that I slid across the bed had something to do with it?

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    $\begingroup$ well... the elecrtic breakdown for air is around 3 MV/m... you were charged my friend! $\endgroup$ – Pietro Oliva Jan 21 '19 at 21:57
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    $\begingroup$ What about this makes you feel like it was something other than a "normal" occurrence of static shock, which you seem to be more familiar with? $\endgroup$ – BioPhysicist Jan 21 '19 at 22:03
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    $\begingroup$ I would say that it's not so uncommon ending up with few kV of potential difference with respect to ground. I am actually able to reproduce it right now with my blanket... but don't ask me to do it, i'm sensible... $\endgroup$ – Pietro Oliva Jan 21 '19 at 22:06
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I agree with Niels. You probably experienced an electrostatic discharge to due electrical charge build up on your body. The outlet is grounded so it probably provided you with a convenient path through the air to ground to discharge your body. And the voltage between you finger and the outlet was great enough to break down the air and cause the "spark".

While the voltage is quite large, on the order of thousands of volts, it is not voltage that harms you, its the amount of current the voltage produces in your body. Electrostatic discharge currents are only on the order of tens to a couple of hundred microamperes. The current necessary to cause a harmful electric shock (ventricular fibrillation) is on the order of tens of milliamperes. A startle reaction, which is not harmful (unless you injure yourself because of the way you react to the current, like bumping into something), requires on the order of a few tenths to a several milliamperes. That's likely the level you experienced.

Hope this helps.

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In low humidity conditions, static electric buildup due to friction between dissimilar materials can be severe enough to destroy things like field effect transistors. The most likely explanation for your shocking experience is that you charged yourself up via rubbing the bedspread with your behind, or scuffing your slippers on the carpet, and then discharged yourself on the charger housing.

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