Great Scientists: From Euclid to Stephen Hawking by John Farndon

Author:John Farndon
Language: eng
Format: mobi, epub
ISBN: 9780760791974
Publisher: Metro Books
Published: 2007-09-15T07:00:00+00:00

Forces of nature

Newton had, with his concept of gravitation, made respectable the idea of an invisible force that exerted its effect through empty space, but this idea of ‘action-at-a-distance’ was beginning to look shaky to an increasing number of scientists in the early nineteenth century. By 1830, Thomas Young and Augustin Fresnel had shown that light did not travel as particles, as Newton had said, but as waves or vibrations. But if this was so, what was vibrating? To answer this, scientists came up with the idea of a weightless matter called ‘ether’.

Faraday had another idea. He came to believe in the idea of fields made up of lines of force – the lines of force demonstrated so graphically by the patterns of iron filings around a magnet. This meant that action at a distance simply did not happen, but things moved only when they encountered these lines of force, which were not imaginary, but had a physical reality. Faraday appreciated that magnets induced electric currents by creating moving lines of magnetic force that carried an electrical charge as they moved.

The idea of fields of force is almost taken for granted, but in Faraday’s time it was so radical that few even understood it, let alone agreed with it. They could see the idea of areas of magnetic influence, but the idea of electro-magnetic fields was completely beyond them. Mathematicians dismissed Faraday’s ideas for their lack of mathematics. In 1855, Faraday wrote, ‘How few understand the physical lines of force. They will not see them, yet all the researches on the subject tend to confirm the views I put forth many years since … I am content to wait, convinced as I am of the truth of my views.’ And he was right.

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