Zapping someone with your finger is sure to elicit a lot of laughs when you’re 11, but static electricity is one of those things that loses its magic with age. After all, it’s the bane of good hair days and, if you have cats, they probably don’t appreciate getting shocked whenever you pet them (sorry, Fluffy). So how exactly is static electricity created, and why does it seem to occur more frequently in the winter?
To hark back to a high school science lesson: Static electricity is created when there’s an imbalance between the positive and negative charges of two objects. Most of the objects you use on a daily basis are electrically neutral. In other words, the protons (positive charge) and electrons (negative charge) that make up their atoms balance each other out, and no one gets shocked. However, the outer electrons in an atom can move around more freely than protons, and sometimes they jump from one surface to another when two materials come into contact.
This often happens when friction is involved. A classic example of this is when you shuffle across a wool carpet while wearing rubber-soled shoes. Wool—like rubber, wood, glass, plastic, and fur—is an insulator. This means that the electrons in wool are more tightly bound to the atom and are unlikely to budge. Since rubber and wool are both insulating materials, an even stronger electrical charge is likely to build up in your body, Lifehacker explains.
Essentially, one object becomes more positively charged because it doesn’t have enough protons, while the other one becomes more negatively charged because it has too many electrons. If one of those charged objects—like you—were to touch a conductor, like a metal doorknob, then the charge would be neutralized. This release is what creates a shock, or static discharge. It’s all part of nature’s attempt to restore order and balance.
That brings us to the second part of the question. The reason static electricity is more common in the winter is because the air humidity is lower. The dry air is less conductive, resulting in more powerful zaps. The Moon and Mars, for instance, are especially dry environments, so future astronauts (or colonizers) should take measures to avoid shocking their electronic equipment. Although static electricity is usually harmless, under just the right conditions it can cause flammable substances to ignite or explode, and it can also be harmful to electronics.
It isn’t all bad, though. A controlled form of triboelectric charging, as static charges are also known, is the technology behind copiers and laser printers. The key is knowing how to control it—and there are a few tricks you can try at home to reduce your exposure to unpleasant shocks.
If you want to pet your cat without zapping her, dip your fingers in water first. This will help remove the charge from static electricity so you don’t pass it to along to your unsuspecting fur baby. Humidifiers also help by releasing more moisture into the air and making it more conductive. Lifehacker also recommends swapping out your rubber-soled shoes for leather ones (or just going barefoot), and avoiding wool socks and sweaters.
Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at email@example.com.