Our 21st century lives revolve around electricity and the power it provides to numerous electronic devices that have become the norm for managing our everyday lives, as well as creature comforts like lighting, heating and air conditioning.
The word “electricity” originates from the Greek word “elektron,” which means “amber,” which is basically fossilized tree resin. A Greek philosopher named Thales of Miletus was the first person to actually study electricity by rubbing amber with lightweight objects like feathers and dust, which resulted in static electricity. “Electrostatics” is the study of static electricity and experiments with it continued into the 17th century when an English physician named William Gilbert began studying static electricity and “magnetism.”
Dr. Gilbert repeated the research conducted by Thales of Miletus and concluded that electronic forces develop because of a rubbing action, which removes a fluid (or “humour”) from one of the objects, which results in an atmosphere around it (or “effluvium”). In fact, he coined the term “electric” to describe those forces and the concept that electricity existed as a “fluid” persisted well into the 1700’s.
In 1729, an English scientist named Stephen Gray concluded that certain materials (like silk) do not conduct electricity and his explanation was that the “fluid” described by Dr. Gilbert could be stopped from traveling altogether, or could travel right through certain objects. This process intrigued scientists and they created glass jars to hold this “fluid” so they could study its effects. Several Dutch instrument makers created a “Leyden jar,” which was a glass jar that contained water and a nail that was able to store an electrical charge. The first time Pieter van Musschenbroek experimented with the jar, he was subjected to a massive electrical shock!
By the end of the 1700’s, the world’s scientific community was beginning to understand the nature of electricity and how it worked. In 1752, Benjamin Franklin conducted his famous kite experiment, from which he concluded that lightning was electrical and that electricity contained both positive and negative elements and that the flow of electricity was always from positive to negative.
Thirty years later, French scientist Charles Augustin de Coulomb began conducting scientific experiments with electricity to determine the elements that affect an electrical force. He concluded that “like” charges “repel” and “opposite” charges “attract” and that they do so with a “force proportional to the product of the charges and inversely proportional to the square of the distance between them.”
This theory became known as “Coulomb’s law” and made it possible to actually calculate the electromagnetic (or static) force between two charged objects.
Later research revealed the source of positive and negative charges and the existence of “electrons” and this is the point at which modern electricity began.
As you know, “matter” is composed of “atoms.” Everything consists of atoms and breaks down into small pieces that form a “nucleus,” which is orbited by one or more “electrons,” each of which has a negative charge. In items like glass, wood, plastic and other substances, the electrons are tightly bound to the atoms and, because they are so reluctant to share electrons, these types of materials do not conduct electricity very well (if they do at all) and are known as “electrical insulators.”
Most metals, on the other hand, do have electrons that can detach from their atom and move around (“free electrons”), which creates loose electrons that allow electricity to easily flow through the object. These types of materials are known as “electrical conductors” because their moving electrons are able to transmit electrical energy.
In conclusion, moving (or loose) free electrons make it possible for electricity to flow from one source to another using electrical conductors like those mentioned above.