Description
Electricity and Magnetism
The brilliant flash of lightning during a thunderstorm might not be new to you. But did you know that it is a discharge of static electricity? It took years and the accumulated work of many scientists to form the foundation of modern ideas about magnetism and electricity. Writings as early as the first century B.C. show that magnetism was a recognized and studied phenomena.Magnetite, a naturally occurring magnetized rock that attracts iron objects, was available and used to study magnetism by some ancient civilizations. The origins of practical uses for magnetism, such as in compasses, are unknown but they were used centuries before the first writings about magnetism appeared
Research and Development
Petrus Peregrinus de Maricourt, a French scientist, published the first documented research study of magnets in 1269. He used magnetite, or lodestone, and a thin, iron rectangle to study the magnetic field generated by the magnetite. Over 300 years later in 1600,William Gilbert, an English physician, published a book called Of Magnets, Magnetic Bodies, and the Great Magnet of the Earth. He studied electricity and magnetism and made the analogy that Earth behaves like a giant magnet.
The Leyden Jar
In 1746, the Leyden jar was invented by Pieter van Musschenbroek, a Dutch physicist. This provided a cheap and convenient source of electric charges used to study electricity. One form of a Leyden jar is a glass vial partially filled with water that contains a conducting wire capable of storing a large amount of static charge. According to legend, Benjamin Franklin used a Leyden jar when he flew a silk kite during a thunderstorm to show that lightning was an electrical discharge. Franklin’s kite was connected by a key on a wet string attached to a Leyden jar. The lightning strike would have
Magnetism and Electricity are Related
In 1820, Hans Oersted, a Dutch scientist, discovered that current flowing through a wire deflected a compass needle. This discovery showed a link between electricity and magnetism. Later that year, André Ampère, a French scientist, performed extensive studies on the magnetic fields generated by electric currents and established the laws of magnetic force between electric currents.Michael Faraday, an English scientist, heard about Oersted’s work and continued to study the relationship between magnetism and electric current. In 1831, he discovered that moving a magnet near a wire induced a current in the wire. Oersted showed that an electric current creates a magnetic field and Faraday showed that a magnetic field creates an electric currentcaused the Leyden jar to become charged.