Has your hair ever literally stood on end? You may not have been scared, but you were probably shocked. The scientific term for this is “static electricity.”
Simply put, static electricity is an increase in electric charge on the surface of an object. The charge does one of two things: It either stays on the object until it goes into the ground or it is quickly released through a sudden discharge. A discharge happens when an object is rubbed together with an unlike object, and then separated.
Objects are either “insulators” or “conductors.” Shoes, for example, are usually made of leather and other materials that contain high concentrations of electrons. These are insulators (other common insulators include plastic and glass). In contrast, metals contain high concentrations of positively charged electrons that are far less concentrated. These are conductors. Both insulators and conductors play an important role in how static electricity is produced.
For example, as you walk across a carpet (an insulator), lots of negatively-charged electrons jump from the carpet into your shoes (also an insulator). When you grab a door knob (a conductor), all those electrons suddenly jump from your shoes through your hand into the door knob, giving you a shock.
Another example of static electricity is when your hair sticks out. When you comb your hair, charges can transfer from your hair to the comb, causing the strands to lose negatively charged electrons. Without these, the positively charged hairs repel one another, causing your hair to shoot up (though certain conditions, like high humidity, can prevent this).
Static electricity may seem like a nuisance, especially when you aren’t expecting it. But it has plenty of benefits. For example, air purifiers contain plates that are oppositely charged to that of dust, which allows them to clean dust from the air. Factories use a similar technology for reducing pollution from their smokestacks. Static electricity is also used in nanotechnology to manipulate atoms for useful purposes in certain computer applications.
Celebrate National Static Electricity Day!
National Static Electricity Day is celebrated every January 9th. Static Electricity Day observes static electricity and the science behind it.