Tuesday, July 26, 2005

Waiting for broadband

Today I'll be sitting around waiting for the person from ilDana to install wireless broadband intenet. They've put up an antenna across Ventry Harbor at Cuan Pier that will provide coverage for anyone in line-of-sight, which pretty much covers the parish. One more component to the bath of radiation we live in.

Electromagnetic waves were predicted theoretically by the Scottish physicist James Clerk Maxwell in 1864. Twenty-two years later they were experimentally demonstrated by the German Heinrich Hertz, who in effect made the first radio broadcast and reception. At Hertz's transmitter a spark jumped back and forth between two metal spheres 50 million times a second. Across the room a similar spark was instantly produced at the receiver. Invisible electrical energy had passed through space at the speed of light.

A spark dancing between two spheres -- an unpretentious beginning for the age of radio, television, mobile phones and wireless internet. Some years ago I saw replicas of Hertz's experimental apparatus at the MIT Museum. The replicas were built in the late l920s by German model-maker Julius Orth, working from the originals. The first transmitter and receiver had a basement-workshop simplicity about them. Hertz proved the existence of electromagnetic waves with constructions of wood, wire, string, and sealing wax.

His original radio waves were twenty feet long, later two feet, and his equipment was correspondingly large. His focusing reflectors, refractor, polarizer, coaxial transmission line, and other apparatus filled the room at the MIT Museum like stage props from some 19th century opera. The replicas were beautiful in an antique sort of way -- yellow varnish, tarnished metal, the patina of crusty wax. They evoked the day when a clever person with a halfway-decent workshop and a knack for construction could unravel mysteries of the cosmos.