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The golden age of wireless

Rupert Goodwins AnchorDesk

Published: 12 Dec 2001 16:48 GMT

Got a minute? Step into this time machine, and bring a radio. A good one, mind, with shortwave.

First stop, prehistoric Earth. Tune around and you'll hear some low frequency whistles, crashes from distant thunderstorms, noise from the Sun, perhaps even a star or two. Apart from aurora -- which makes radio waves that sound eerily like birds singing -- and lightning strikes, the Earth is silent across the bands.

Nothing much happens until the mid 19th century, when the birth of electrical machinery starts to add great gouts of pure grinding noise to the airwaves. It's a fact of physics that when you start or stop moving current through a wire, it gives off radio waves -- but nobody knows this yet. That takes a German called Heinrich Hertz, who discovers that a current in one loop of wire can create a spark in another nearby. Hang around his lab with your Sony in the year of his discovery, 1887, and all you'll hear is buzzing.

Things get interesting in 1895, the year after Hertz dies. A young aristocratic Italian, Marconi, sends the first radio signal -- three dots, the Morse for 'S' -- three kilometres around a hill in Italy. Set the time machine controls forward six years to exactly 100 ago, 12th December 1901. A rocky bit of Cornwall has sprouted aerials, as has its counterpoint in Newfoundland. This time, the transmitter is powerful enough to cross the Atlantic, and thoroughly untuned -- our radio picks up the di-di-dit of the by now traditional S all over the place.

From this point on, the primordial peace of the airwaves is a thing of the past. Transmissions multiply beyond count. The 20th century belongs to wireless -- Churchill's growling defiance, Armstrong on the moon, TV pictures of the fall of the Berlin Wall -- and it seems that its dominance is unshakable.

Fast forward to the present day, though, and tune to 800KHz, where the original transatlantic transmission is thought to have taken place. If you're lucky, you'll get an AM station. More likely, you'll get an ungodly racket: radio frequency energy is at the heart of all our digital equipment, and it leaks all over the place. Put your radio next to your computer, and you'll hear your PC thinking. It's not a pretty noise.