The Path of Discovery: Electricity

The curious thing about electricity is that it has been studied for thousands of years, and we only very recently learned how it actually functions. Today, all matter is though to consist of tiny charged particles, called neutrons, electrons, and protons. Electricity, according to this theory, is simply a moving stream of electrons or other charged particles (yes, you can make protons jump atom to atom! Takes allot of work, but it can be done).

The word "electricity" comes from the Greek word electron. Electron is their word for the stone amber. As far back as 600BC, the Greeks knew that when amber was rubbed for a while (building up a static charge), it became capable of attracting light bits of cork or paper to itself. They never understood exactly how static forces worked, but accepted them without proof. The English scientist William Gilbert, in 1600, was the first one to tie the Greek word to its meaning today. As a result, Gilbert is called the father of modern electricity.

Not much progress was made in the study of electricity until 1672. In that year, a man named Otto von Guericke produced a more powerful charge of electricity by holding his hand against a ball of spinning sulfur. 'Successors, such as Francis Hauksbee, made improvements that provided experimenters with source of static electricity. Today's version of these early machines is the Van de Graaf generator, which is sometimes used as a particle accelerator. Also, in 1675, Robert Boyle realized that attraction and repulsion were mutual and that electric force could be transmitted through a vacuum.’ (History, 3)In 1729, Stephen Gray found that some substances, such as metals, carried electricity from one location to another. These became known as "conductors." Then, it was discovered that other substances, such as wax, glass, and cloth, cannot carry electricity, and are therefore known as "insulators."

The next important step took place in 1733, when a Frenchman called du Fay discovered positive and negative charges of electricity, although he thought these were two different kinds of electricity.

But it was Benjamin Franklin who tried to explain what electricity was. His idea was that all substances in nature contain "electrical fluid." Friction between certain substances removed some of this "fluid" and placed an extra amount in the other. Today, we would say that this "fluid" is composed of electrons which are negatively charged.

A new interest began with the invention of the battery. In 1786, Luigi Galvani figured out that a jolt of electricity made a (dead) frog's leg jerk. Based on this idea, he managed to produce a simple cell using the fluids of the leg as an electrolyte and the muscle as a circuit and indicator. Galvani thought the leg supplied electricity, but Alessandro Volta thought otherwise, and he built the voltaic pile, an early type of battery, as proof. Probably the most important developments in the science of electricity started with Volta's invention of the first battery in 1800. This battery gave the world its first continuous, reliable source of electric current, and led to all the important discoveries of the uses of electricity. (sections from History, 4-5)

In 1819, Hans Christian Oersted discovered that a magnetic field surrounds a charged wire. Within two years, Andre Marie Ampère had put several electromagnetic laws into mathematical form, D. F. Arago had invented the electromagnet, and Michael Faraday had devised a crude form of electric motor. He managed to make a disk start and stop spinning by either adding or removing electrical current to an apparatus. A practical use of the motor had to wait 10 years, however, until Faraday invented the electric generator with which to power the motor. A year after Faraday's laboratory approximation of the generator, Hippolyte Pixii (what a name...) constructed a hand-driven model. From then on engineers took over from the scientists, and a slow development followed. The first power stations were built 50 years later. (History 5-6)

The History Channel:
Sources from History Channel: See D. L. Anderson, Discovery of the Electron: The Development of the Atomic Concept of Electricity (1964); W. T. Scott, The Physics of Electricity and Magnetism (2d ed. 1966); M. Kaufman and J. A. Wilson, Basic Electricity (1973); E. T. Whittaker, History of Theories of Aether and Electricity (1954, repr. 1987).