To ward the end of the 19th century, scien ce was barreling along at an impressive pace. Automobiles andaircraft were on the verge of changing the way the world mov ed, and electric power was st eadily making its way into more and more homes. Yet even scientists of the day still viewed electricity as something vaguely mystical. It wasn't until 1897 that scientists discovered the existence ofelectrons -- and this is where electricity starts.
Matter, as you probably know, is composed of atoms. Break something down to small enough pieces and you wind up with a nucleus orbited by one or more electrons, each with a negative charge. In many materials, the electrons are tightly bound to the atoms. Wood, glass, plastic, ceramic, air, cotton -- these are all examples of materials in which electrons stick with their atoms. Because the electrons don't move, these materials can't conduct electricity very well, if at all. These materials areelectrical insulators.
In the late 19th century, electricity truly had a noble or even divine reputation -- to the extent that members of the scientific community protested the idea of the electric chair as a degradation of both electricity and the scientific breakthroughs that made electrocuting a criminal possible. What might these critics have thought of such modern marvels as the battery-powered blackhead remover or the dance-floor horror known as the electric slide?
Most metals, however, have electrons that can detach from their atoms and zip around. These are called free electrons. The loose electrons make it easy for electricity to flow through these materials, so they're known as electrical conductors. They conduct electricity. The moving electrons transmit electrical energy from one point to another.
Think of electrons as pet dogs and a negative charge as a case of fleas. Homes where the dogs lived inside or within a fenced-in area would be the equivalent of an electrical insulator. Homes where the pets roamed free, however, would be electrical conductors. If you had one neighborhood of indoor, pampered pugs and one neighborhood of unfenced, free-roaming basset hounds, which group do you think could spread an outbreak of fleas the fastest?
Dogs aside, electricity needs a conductor in order to move. There also has to be something to make the electricity flow from one point to another through the conductor. One way to get electricity flowing is to use a generator.