Robyn Arianrhod on the sesquicentential one of the most important discoveries that helped create the world we live in today:
It’s hard to imagine life without mobile phones, radio and television. Yet the discovery of the electromagnetic waves that underpin such technologies grew out of an abstract theory that’s 150 years old.
Our knowledge of the existence of such waves is a direct result of James Clerk Maxwell’s theory of electromagnetism which was first published in January 1865.
Electromagnetism itself was discovered physically rather than theoretically. Some time around 1820, the Danish physicist Hans Oersted noticed that when you switch on an electric current, a nearby magnet – such as the needle of a compass – actually jumps, as if the changing electric current was itself a magnet.
Then, in 1831 (the year Maxwell was born in Edinburgh) the English physicist and chemist Michael Faraday discovered that if you move a magnet through a coil of wire, you create an electric current in the wire without the aid of batteries or other electricity supply.
Faraday was so intrigued by the surprising ability of moving magnets to create electricity that he created a tiny prototype of the electric generator. He also created a prototype of the electric motor, but it would take decades before engineers were able to develop working motors and generators.
Nevertheless, basic technologies had begun to flow almost immediately after the phenomenon of electromagnetism was discovered: in particular, the telegraph – the first high-speed global telecommunications system.
