Everyday Einstein uncovers the shocking truth behind static electricity. Plus – a fun experiment you can do at home!
It’s that time of year when some of us develop a dread of touching doorknobs. The cooler months of fall and winter seem to bring an increase to the annoying little shocks that we sometimes feel when touching metal objects. But why do these little demons of pain seem to afflict us only in the colder months? Let’s take a look at the science behind these shocks to find out.
Every time you take a step, the bottom of your shoe forms a series of chemical and mechanical bonds with the surface of whatever you’re stepping on. As you might remember from my episode on Atomic Bonds, electrons tend to move between atoms in an attempt to satisfy the needs of greedy atoms. This means that when your shoe forms a temporary bond with the floor, some electrons are transferred between the two.
When you lift up your shoe to take another step, some of those extra electrons it picked up remain behind, giving it an electric charge. Because your shoe is an insulator, this electrical charge doesn’t have anywhere to go. That’s why it’s called static electricity. It just hangs out on your shoe, getting stronger with every passing step.
Don’t Let the Door Hit You on the Way Out!
Eventually you might realize that you’ve had enough of this shuffling around on the carpet and decide to go outside. As you reach for the doorknob, the electrical charge that has built up around your body sees its chance to escape. (Remember that an electrical charge represents an imbalance of electrons.) Those extra electrons know that they aren’t wanted and so when you touch a conductive surface, such as a metal doorknob, they leave in a hurry.
Unfortunately for you, the way they leave is via an electrostatic discharge...