It is cold and clear here in Colorado. Snow covers the ground. The relative humidity has dropped to the point where everyone needs lip balm, hand lotion, and rubber gloves. (EEP! Did he just say rubber gloves? What kind of web page is this?) My four year old just zapped me with a static shock big enough to feel like a small bee sting, and he isn’t even wearing socks. We should all be required to wear rubber gloves this time of year.
My computer is one year and two weeks old. How do I remember that so well? I walked in to turn on my computer this time last year and a spark jumped an inch out from my finger to the power button and fried the motherboard. (unenthusiastic whee). I now know how to replace, uninstall, and return a power supply, which is what everyone told me it was, but it was my motherboard. I know how to replace one of those now, too, but that is a whole rant I could spend days enjoying being ticked off with.
So why is this time of year so shocking? Well, it can happen anytime of year, but the lower the humidity, the better the chance of sparks flying, and with the weather below freezing for any period of time the ambient moisture dissipates pretty quickly. The triboelectric effect, one of the causes of static electricity, is the cause of the static discharges most of us are familiar with. Socks across carpet create the friction, building up the imbalance that leads to the surprise at the doorknob or light switch.
So is it dangerous? It can be. On a large scale, obviously. Although the exact causes of lightning are debated, mostly because there may be so many, it does appear to be a giant static spark. So yes. But for practicality, lets stick to the little ones. Are the little ones dangerous? Deadly so, in the right conditions.
Ever heard the urban myth that a static spark at the gas pump will cause an explosion? Check out the Petroleum Equipment Institute’s Stop Static Campaign and view the video. Curiously, they have found no evidence of cell phones causing this. But then, my cell phone has never shocked me, has yours?
The other real danger is a Dust Explosion. These are caused by a flammable dust in the air coming in contact with an ignition, and, yes, a static spark can be a big enough ignition. Common flammable dusts are coal, grain, flour, sawdust, and powdered milk, although there are many. All right, not coal so much anymore for most of us, but don’t mix your baby formula next to a lit burner.
In July 2007, an explosion at the Barton Solvents Distribution Facility caused the evacuation of 6,000 residents and was attributed to a static spark.
Some people credit the Hindenburg disaster to static sparks, but no one knows for sure.
And, once upon a time, people were afraid of a static spark explosion in the operating room. You know, where you get operated on. Surgery. Yikes! (Fortunately not so much anymore.)
Is static electricity dangerous? According to NASA Blogs, launches can be cancelled on clear nights to avoid just to avoid it, just in case.
Further (I thought) interesting reading:
Jeremy Smallwood’s Static Electricity Page