Zeros to heroes: What's the use of electricity?

 作者:杜佑增     |      日期:2017-12-05 04:01:00
By Roger Highfield Michael Faraday built an electric motor in 1821 and a rudimentary generator a decade later – but half a century passed before electric power took off OF THE many stories of how unlikely discoveries can change the world, this is the best known and remains the most relevant. Whether it is true in fact, or merely in spirit, remains an open question. In 1821, while working at the Royal Institution in London, Michael Faraday followed up the work of the Dane Hans Christian Ørsted, who, alerted by a twitching compass needle, deduced that electricity and magnetism were linked together. Faraday developed the electric motor and then, a decade later, found that a magnet moving in a wire coil induced a current. In 1845, he formulated that cornerstone of modern physics, the field theory of electromagnetism. As the story is usually told, the prime minister or some other senior politician was given a demonstration of induction by Faraday. When asked “What good is it?” Faraday replied: “What good is a newborn baby?” Or maybe he said: “Soon you will be able to tax it.” The former version of the story originated in a letter sent in 1783 by Faraday’s great predecessor in matters electrical, the American philosopher and politician Benjamin Franklin (Nature, vol 157, p 196). As for the source of the latter, no one knows. Whatever was said at the time, the lesson is that it can take half a century for an investment in basic science to bear fruit. Faraday’s insights were applied in the 1850s in a failed attempt to build an electrically lit lighthouse,