How powerful can static electricity get?

Factual Questions
1

Firstly, is lightning a form of static electricity? because if it is, then I would assume it could be pretty damn strong.

I ask this question because back in my childhood, a friend of mine and I were at this playground where they had this twisting plastic slide. Sliding down it would generate a lot of static. My friend slid down it, followed by me. We saw each other’s hair stand on end and pointed and laughed. Suddenly, there was a sound like a gunshot and I saw a spark that must have been the size of a volleyball. Both my friend and I were knocked to the ground but unhurt. Ever hear of this happening?

2

Lightning is an electric current caused by two areas of opposite electric charge inside a thunderstorm. So yes, it’s the LARGE version of the sparks which you can make by rubbing a balloon on your head.

As for size, the Museum of Science in Boston has an electrostatic generator from the 1930s which is a couple of stories tall, and it makes 10ft lightning bolts. They sound like the noise from a starter pistol.

http://www.mos.org/whats_happening/schedule/show49.html

I bet the slide charged up your bodies to almost a million volts. The spark might make your muscles jerk. But a gunshot?

When I see those plastic slides, I always try to make that happen, but it never works because the slides I’ve found always have metal rivets. I bet they put them there to keep discharging the kids’ bodies as they pass by.

Contrary to what your grade-school textbook says, “Static electricity” is not a kind of electricity. Instead it is a field of science.

For example, in the field of science called fluid dynamics we have “hydrostatics” and “hydrodynamics”. But there is no such thing as “static water!”

“Static” electricity misconceptions
http://amasci.com/emotor/stmiscon.html

When you rub a balloon on your head, you “un-cancel” some positive and negative electric charge that was already in the rubber and in your hair. It’s called “electric charge”, not “static electricity.” Electric charge can cause sparks. You’ll often see these sparks if you rub a balloon on your head in the dark, and if you hear a crackling noise, sparks are definitely occuring. When you peel clothes apart that have been in the dryer, if you hear snaps and pops, you can try looking for dim purple sparks if first you turn off the lights!

3
      • I recall reading that the static charge on jetliners after they land is enough to ignite spilled fuel and/or cause personal injury (just from electrical shock, mind ya), and that the first order of business is to ground the airplane by touching it with a rod/grounded wire arrangement. No cite tho’… - DougC
4

Charge buildup can pretty much be as large as the breakdown voltage in a medium. The breakdown voltage of air is about 71 kV per inch. This is the amount of voltage potential necessary to allow electricity to flow across the medium in question; once that level is reached, excess charges will cause a spark to equalize themselves.

5

The word static'' in this context means not dynamic,’’ meaning ``not changing,’’ so of course there is static (still) water. I also find it quite reasonable to call charge that is not flowing static (not moving) electricity.

6

[slight hijack]
By the way, when I was a child, and, as a matter of fact well into the late 1940’s at least, all fuel tank trucks had a chain fastened to the frame that dragged on the roadway to discharge them.

This is no longer the case. What happened. (I know that before discharging their cargo, there is a grounding cable connected from truck to grounding point near the fuel stations tanks.)
[/slight hijack]

7

I saw drag-chains on trucks as a kid, up to 1963 or so.

For many applications, black rubber is better than gum rubber. Black rubber is full of carbon powder. Someone discovered that if you add even more carbon powder to automotive rubber than usual, it becomes slightly conductive. Conductive tires eliminated the need for drag-chains, and eliminated lots of mayhem caused when car owners touched the tip of a metal gas-pump nozzle to the metal of a highly charged vehicle.

8

But would you say that there are two separate kinds of water called “static” water and “current” water?

If surface charge starts flowing, it will still make your hair stand up. It will still attract dust, will still cause sparking… in fact, none of the characteristics of so-called “static electricity” will be lost if the “electricity” starts flowing along very non-statically.

In fact, what we call “static electricity” is just electric net charge. A conductor can have a net charge or an electric current or both. Net charge is not the opposite of current, so “static” electricity is not electricity which remains static.

But wait a moment. Net-charge exists an many places, including all electric circuits, but a flashlight battery won’t attract lint or make your arm hair stand up. The difference involves the level of e-field and voltage, and that’s the key to understanding. Our so-called “static electricity” has another name: HIGH VOLTAGE. If you rub a balloon on your head, you can easily create voltages on the order of 100,000V.

High voltage has nothing to do with surface charges remaining “static.” But then, the same is true of “static” electricity: the unmoving state is irrelevant. Static electricity is not electricity which is static, instead it’s electricity which involves high voltage.

Wimshurst machines and VandeGraaff generators and Holtz machines and all those other devices from the 1800s, those are mechanically-driven sources of high voltage.

Read a stack of K-6 grade science textbooks. Most of them say this: there are two different kinds of electricity, STATIC ELECTRICITY and CURRENT ELECTRICITY. So why don’ t they also teach kids that there are two different kinds of water, STATIC WATER and CURRENT WATER? What the heck is “current” water?

What all the K-6 grade school books are trying to say is this: electricity has two main characteristics: CURRENT and VOLTAGE. But instead they spend their time going on and on about “unmoving” electricity. As a result, most people haven’t the foggiest notion of what voltage really is. Those textbooks are supposed to teach kids about electricity, but instead they only teach us about current. Instead of teaching about voltage, they convince us that all the basic voltage phenomena are obsolete Ben-Franklinish stuff which only applies to dryer-cling and photocopiers. And they never even point out that “static electricity” involves voltage!

Heh. Suppose I have a circuit with 10 amperes DC, then I disconnect the power supply. The current has stopped. Please point to the “static electricity.” There are many hundreds of coulombs still there in the wires, and they’re not flowing anymore. Why doesn’t this “static electricity” make your hair stand on end? Simple. The hair-raise effect has everything to do with voltage and net charge, and nothing to do with electric charges which are “static.”

In other words, if we want to make some so-called “static electrcity”, we must separate the existing positive and negative charges, and doing so produces very high voltage. You could call it “separated opposite electricity”, but don’t call it “unmoving” or “static” electricity.

Why not?

Because separated opposite electricity can flow along! SEPARATION IS NOT THE OPPOSITE OF FLOW.

Water analogy: “there are two kinds of water: pressurized water and flowing water.” Sound crazy? That’s what K-6 textbooks have always been trying to say about electricity. They fail in their task, because flowing electricity is not the opposite of “pressurized” electricity, and “pressurized” electrcity involves high voltage, not “static”-ness.

More electricity misconceptions
http://amasci.com/miscon/elect.html

Electricity FAQ
http://amasci.com/elect/elefaq.html

9

It’s still common practice to attach an aircraft to its fuel source with a ground wire, to prevent sparks at the filler neck. Good idea, considering airplanes tend to hold more fuel than cars.

Even plastic tanks need this. Ever see that video shot with a camera inside a plastic gas can as it was being filled? There were sparks jumping around everywhere! Hard to imagine NOT having a fire under those circumstances.

10

Yeah, and also the rain from thunderstorms is charged, so if a large metal object such as an aircraft is sitting on dry pavement, but is intercepting lots of raindrops, the conductive rubber tires won’t help much.

Nope, missed that one. Recently there have been incidents where people put metal gas cans on insulating surfaces, and the gas can charges up as gasoline sprays into it. Plastic liners inside of pickup trucks now have warnings not to fill gas cans while the can is in the truck bed.

CHEVRON: Safety Warning
http://www.chevron.com/prodserv/fuels/bulletin/product_safety.shtml
http://www.pei.org/FRD/gascan.htm