We take it for granted that when we ‘switch on a light’, the light comes on. Electricity is such a fundamental part our lives that we don’t really ever think about what it actually is. How would we explain electricity to a time-traveller from the Middle Ages?

The definition of ‘Electricity’: According to the Oxford dictionary, electricity is ‘a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current.’ Ok – we admit it – this the explanation that comes up first when you Google ‘definition of electricity’, but it will do, because explaining what electricity actually is, can get very complicated when you get down to it. It’s more important to know how electrical current works to power our homes and businesses.

How electricity works:

  • When you flick a light switch, and the light comes on, electricity is working ‘dynamically as a current’. This ‘current’ is the movement of the charged particles. In this case, it’s electrons. These are the negatively charged particles in atoms. When they move, they carry the electrical charge they have with them.
  • In order to get negatively charged electrons to move, they must be attracted by a positive charge in a closed system – negative to positive and back again. This creates a ‘circuit’. This circuit can be a national power grid, the circuit in your home, or a battery – or clouds and the ground in a lightning storm.
  • This flow of electrons is the energy is what we call electricity. When energy flows through the filaments in a light-bulb, we see it as light.

But what if the time-traveller didn’t know what ‘electrons’ are? You could say then, that electricity is lightning that we have learned to make ourselves, store, and send through thin metal strings called wires to make all sort of things we have made, light up and do stuff. You could also say that it’s an energy that powers our lives, without which society as we know it, would collapse. (There’s a nudge-nudge and a wink-wink for you there, Eskom).