Michael Faraday (, – , ) was a (a and ) who contributed significantly to the fields of and . He also invented the earliest form of the device that was to become the , which is used almost universally in science laboratories as a convenient source of heat.
Michael Faraday was one of the great scientists in history. Some historians of science refer to him as the greatest experimentalist in the history of science. It was largely due to his efforts that became viable for use in technology. The unit of , the (symbol F) is named after him.
Michael Faraday was born in , near present-day , . His family was poor (his father, James Faraday, was a blacksmith) and he had to educate himself. At fourteen he became apprenticed to bookbinder and seller and, during his seven year apprenticeship, read many books, developing an interest in science and specifically electricity.
At the age of twenty Faraday attended lectures by the eminent scientist Sir , president of the , and , founder of the . After Faraday sent Davy a sample of notes taken during the lectures, Davy said he would keep Faraday in mind but should stick to his current job of book-binding. After Davy damaged his eyesight in an accident with , also known as trichloramine, he employed Faraday as a secretary. When John Payne of the was fired, Davy recommended Faraday for the job of laboratory assistant. Faraday eagerly left his bookbinding job as his new employer, , was hot-tempered.
In a class-based society, Faraday was not considered a gentleman; it has been said that Davy's wife, , refused to treat him as an equal and, when on a continental tour, made Faraday sit with the servants. However, it was not long before Faraday surpassed Davy.
He also was the first to link electricity to magnetism and then link magnetism back to electricity - i.e. he induced an electric current using magnets - thus inventing the dynamo, predecessor to today's .
His greatest work was with electricity. In , soon after the Danish chemist, discovered the phenomenon of , Davy and tried but failed to design an . Faraday, having discussed the problem with the two men, went on to build two devices to produce what he called electromagnetic rotation: a continuous circular motion from the circular magnetic force around a wire. A wire extending into a pool of with a magnet placed inside would rotate around the magnet if charged with electricity by a chemical battery. This device is known as a . These experiments and inventions form the foundation of modern electromagnetic technology. Unwisely, Faraday published his results without acknowledging his debt to Wollaston and Davy, and the resulting controversy caused Faraday to withdraw from electromagnetic research for several years.
Ten years later, in , he began his great series of experiments in which he discovered , though the discovery may have been anticipated by the work of . He found that if he moved a magnet through a loop of wire, an electric current flowed in the wire. The current also flowed if the loop was moved over a stationary magnet.
His demonstrations established that a changing magnetic field produces an electric field. This relation was mathematically modelled by , which subsequently became one of the four . These in turn evolved into the generalization known as field theory.
Faraday then used the principle to construct the electric , the ancestor of modern power generators.
Faraday proposed that electromagnetic forces extended into the empty space around the conductor, but did not complete his work involving that proposal. Faraday's concept of lines of flux emanating from charged bodies and magnets provided a way to visualize electric and magnetic fields. That mental model was crucial to the successful development of electromechanical devices which dominated engineering and industry for the remainder of the 19th century.
Faraday also dabbled in , discovering chemical substances such as , inventing the system of numbers, and liquefying gases such as .