an English chemist and physicist, made very important contributions to scientific knowledge of electricity and magnetism. His work helped make possible the development of electrical power. Moreover, Faraday's theories on electricity and magnetism established the basis for more complete theoretical understanding of these forces.
Faraday also made important discoveries in chemistry. Only a handful of scientists in the 1800's made as great an impact on later developments in science and technology as Faraday. As a young man, Faraday served as assistant to Sir Humphry Davy, the great chemist. Eventually, Faraday made important chemical discoveries on his own. He isolated benzene, an organic compound, and described its molecular structure. He was the first to synthesize compounds out of the elements carbon and chlorine. In the 1820's, however, Faraday turned his affention to electricity and magnetism. These topics became the scientific passion of his life. Faraday is most remembered for his work wit~ them. Jwo physicists had made important discoveries about electricity in the early 1820's. Physicist Hans Christian Oersted, a Dane, discovered that electrical current flowing through a wire produces a magnetic field around the wire. Then, French physicist Andre-Mane Ampere found that the magnetic field produced in this way is circular. As a result, the field around a current-carrying wire has the shape of a cylinder. A cylinder is a type of circular shape in space, like a can or a tube.
Faraday extended this understanding of electricity and magnetism. He speculated that a magnetic pole would move constantly in a circular path through the electromagnetic field around a current-carrying wire. Faraday proved this idea experimentally. He developed a device in which a magnet is left free at one end to rotate around a wire when current is applied. Faraday's experiment worked as he had suspected-and also demonstrated for the first time the principle of the electric motor. Faraday's next important discovery--of electrical induction-came in 1831. When a current is started in a wire, the process is called electromagnetic induction. Faraday found that the current could be started, or induced, by moving a magnet in and out of a coil of wire. This discovery several months earlier. But Faraday published his results first. Faraday had a strong interest in the theoretical aspects of science. He was dissatisfied with making such discoveries as electromagnetic induction without also understanding thE underlying physics. To this end he devoted much of his scientific career. Although he never completely worked out electromagnetic theory, his ideas deeply influenced later physicists. Many scientists of Faraday's time thought that electricity is a liquidlike substance that flows through wires just as water flows through pipes. Faraday, however, gradually developed radically different ideas. He believed that electricity was caused by build-up of tension or strain in maffer. The tension increases to a breaking point; then it is passed outward from the source. The build-up and release of tension occurs in rapid cycles, and tension is distributed in waves. Later scientific understanding would show Faraday's concept of electrical current to be remarkably accurate
In later life, Faraday further refined these ideas. He theorized on the way force fields-such as those created by electricity, magnetism, or gravity-work in space that is not occupied by maffer. These ideas laid the groundwork for later development of field theory, which considers the nature of force fields. James Clerk Maxwell, a British physicist active in the later 1800's, developed these ideas mathematically. Faraday's experimental work in electricity also led to important discoveries in electrochemistry. He discovered the mathematical relationship between electricity and the valence, that is, the combining power, of a chemical element. Faraday's law states this relationship. It gave the first clue to the existence of electrons Michael Faraday was born in 1791 in a country village in Surrey, England. He came from a rather poor family. The Faradays belonged to a small Protestant religious group called the Sandemanians. The strict, simple piety of Faradav's childhood deeply affected his thinking throughout life. Though little opportunity was available to the child of a rural, poor blacksmith at that time, young Michael managed to get a job with a bookbinder. This proved a fortunate turn of fate, because the work enabled Faraday to get books to read. During this time, Faraday came upon a book about electricity. Thus began his lifelong interest in electricity. Unable to afford higher education, the teen-ager set up his own crude laboratory and conducted experiments. The second great stroke of fortune in Faradays youth was to become acquainted with the chemist Sir Humphry Davy. A combination of Faradays own persistent efforts and good luck led to his appointment as Davy's assistant in 1813. Faraday was a lilile over 20 years old at the time. This marked the beginning of a long, productive scientific career for the young man. In addition to his experimental work, Faraday became one of the most popular lecturers of his day. Tragically, during the last decade or so of his life, Faraday sank into senility, a condition in which one's mental powers decline. Queen Victoria provided a house for the great scientist to live out his days. Faraday died in 1867. The farad, a unit used to measure electrical capacitance, was named for him.
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