⚡ What Exactly is Electricity? Copy

In this section, you will learn:

💡 What an electric charge is

💡 What static electricity is

💡 How the movement of electricity is shown by engineers and in the industry

Photo by Anthony Indraus on Unsplash

What is electricity?  How can we understand it and control it to do what we want?  Where do we start?

Can you see it? 

Yes, in a way.  We’ve all seen lightning storms, and lightning bolts are definitely electrical discharges.  If you’re not careful and short-circuit some power sources, like a wall outlet or a car battery, you get sparks.  And if you watch very closely in a dark room, you can see a little blue flash when a big charge of static electricity jumps from your hand to the door knob.

Can you feel it?

Many of you already know the answer to this question because it has happened to you! Static shocks can really hurt and are fairly common! These electrical discharges are relatively weak though. You really don’t want to get shocked by electricity with higher amounts of electrical current as it’s not safe and can hurt much more than a tiny static shock.

Can you hear it?

Yes! There are actually a couple of different ways that you can hear electricity! You may hear a sound if there is a large enough static discharge. This sound is caused by the rapid thermal expansion of atoms around the static discharge. You may also hear a constant buzzing in electrical appliances which is called “mains hum.”

But…can you smell it?

YES! In the instances where you can see or hear electricity (as with lightning) you’ll notice a distinct chlorine-like smell. This is from the ozone gas byproduct due to the surrounding air molecules becoming charged. 

Photo by Alex Dukhanov on Unsplash

But what’s really happening here?  What makes those flashes, sparks and tingling sensations?

All of these events result from an excess of electric charge, moving from an area with a high concentration of electric charge to an area with a lower concentration of that type of charge. 

Electric charge is a collection of excess negative subatomic particles called electrons.  When excess charges accumulate on an object and cannot immediately flow to an area with a balancing opposite positive charge, this results in static electricity.  We call it “static” because it isn’t moving—until it does, all at once.

Photo by Circuit Globe

When static electricity builds up enough that it can jump to another object to balance itself, we get a spark or a flash of electricity.  You touching the doorknob makes only a very small (but often still visible) flash; lightning jumping from ground to cloud or cloud to cloud is a huge flash, seen from miles away.  Yes—that is a LOT of static electricity being discharged very quickly, which is why lightning is so dangerous.

Something to understand about how the flow of electricity is described and illustrated:  While it is true that actual electric current is made of negatively charged electrons flowing from an area with high negative electric charge towards an area with high positive charge, almost all of the engineering descriptions and illustrations of electric current show the exact opposite:  current is shown flowing in the other direction, from positive to negative.

The reason for this is complicated and buried in history.  But you should know that we will be following the engineering convention of showing electricity as flowing from positive to negative, because that is simply how it’s done in industry.