Star Turn

Problems understanding radars? Melody Mellor discovers that it's as easy as knocking out a fluffy bunny and downing a wee dram.

Desmond McLernon takes a sip of whiskey as the students shuffle to their seats. The students look bemused. "I don't usually drink during lectures," he tells them. "I bet you're wondering what Jamieson's Irish whiskey has to do with this lecture. But without it, none of today's modern communication technology would be possible."

Placing his glass to one side, Dr McLernon launches into his lecture: "From Morse to the Internet: a History of Electronic Communications". The two-hour talk is for MA students from mostly non-science backgrounds from the Institute of Communications Studies at Leeds University. The purpose is to chart the progress of electronic communications from their humble beginnings in 1837 to the present.

Dr McLernon delivers a fact-packed lecture with wit and authority. He uses an array of electronic devices: a tiny lapel microphone amplifies his voice; a "magic wand" highlights sections of the Powerpoint-generated screen; computer animation and soundclips illustrate technical points; and a "visualiser" amplifies images of seminal electronic artefacts on screen. It is a far cry from chalk and talk.

Electronic communication began in 1844 with Samuel Morse's public telegraph service's famous message, "What hath God wrought?" explains Dr McLernon. "I've often wondered what this meant." Telegraphs made an immediate social, political and military impact. Communications between generals in the field and politicians in different countries could be sent in hours instead of days and weeks. The conduct of the Crimean war, for example, was aided by a hastily built 340-mile submarine cable to the Crimean peninsula.

Wireless communications were developed in the late 19th century. James Clerk Maxwell's mathematical theory of electromagnetic waves travelling at the speed of light was verified by Heinrich Hertz, but it was Guglielmo Marconi, a young Italian with no formal university education, who exploited this discovery with wireless telegraphy and voice communication.

Dr McLernon and Dave Whiteley, a computer expert from the West Yorkshire Bat Group, use a live bat, sonagram and banter to illustrate the frequency and wavelength of electromagnetic radiation. Bats use ultrasound (non-electromagnetic waves) to map surroundings. Low frequencies (large wavelengths) detect big, inedible objects such as trees. High frequencies (small wavelengths) identify small, tasty objects.

Dr McLernon and Mr Whiteley then start bouncing small rubber balls off the floor and knocking furry toys into nets to student cheers. The large bounces represent low frequencies and miss the toys, the small bounces hit. The idea is to demonstrate the need for smaller wavelengths to "hit" smaller targets - the principle behind electromagnetic radar.

Dr McLernon describes how electronics has made it possible to amplify, transmit and receive signals over longer distances. The triode thermionic valve (1907) preceded its solid-state equivalent, the transistor, in 1947.

Modern computers are built around integrated circuits - many transistors on a single piece of silicon - developed by Jack Kilby in 1958. Complex mathematical signal-processing algorithms, implemented on smaller and faster integrated circuits, today mean that the proliferation and refinement of electronic communications seems unstoppable.

Recent developments include a Samsung cellular watchphone akin to a Star Trek communicator and the first commercial imaging satellite (Ikonos) with one-metre picture resolution. Transistors are now so small that they use molecules as building blocks. More than 1,000 million transistors can be held on a single chip. Optical communication speeds of tera (one million million) bits per second will be viable soon, in comparison with Morse's equivalent of about four bits per second.

"Teenagers will soon be carrying mobile pocket videophones. It sounds like science fiction but it's only a matter of time as processing speed and bandwidths increase. The future of electronic communication is almost anything you can imagine," says Dr McLernon.

And the whiskey? After taking another generous drink, Dr McLernon explains. "In the 19th century, a girl was born in County Wexford to a prominent Irish family. She was a great singer and had ambitions to perform at Covent Garden but her parents forbade it.

"They consoled her with a trip to Italy and it was there that she met and married an Italian gentleman twice her age. She bore him a son, christened Guglielmo Marconi. His Irish mother was called Annie Jamieson. Cheers."