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Susan Douglas on: The Concept of Wireless Communication
Susan Douglas Q: Tell me about this idea of the gap existing between revolutions in transportation and communication and coming together.

SD: As this century of progress came to close, there were two revolutions that were especially celebrated: the revolution in transportation and the revolution in communication. On the transportation side, of course, there had been enormous changes in railroad technology, streetcars, and in ship technology. Ships become bigger, faster. On the other hand, there had been revolutions in telegraph, cable, telephone, but these revolutions had not converged yet. And what was so powerful and compelling about wireless aboard ships was that it brought those two revolutions together so that you had speedier, bigger ships that now also were no longer incommunicado once they were out at sea. With wireless people felt that there was something instantaneous about life that there hadn't quite been before. That they could send a message and just a few minutes later it would arrive some place else, and there really was a sense that they could be simultaneously in two places at once. That they could send a message that really vaulted them over space and time in a way that was very new and quite magical.

The electromagnetic spectrum is a very difficult concept to wrap your mind around. It's invisible, we can't see it, we can't feel it, we can't smell it. And it was a difficult concept in 1899, and it's s difficult one today. And the most common metaphor that's been used to help people understand how radio works is the pond and the stone. You throw a stone into a pond and waves radiate out and the farther they get away from the stone, which is the transmitter, the more they dissipate and die out. One concept that emerged in the 1890s to help people understand that these waves moved through something was the ether. The ether was thought to be this sort of mystical magical medium through which radio waves moved and it helped people kind of understand or get a material grip on how radio waves might operate.

Wireless is based on the principal that rapid changes in electric or magnetic forces send waves spreading out through space. One way to achieve such a change is with a spark. And that's what Marconi initially used. Now he moderated the spark--short for dots, long for dashes--with the telegraph key. When he pressed down a telegraph key, the spark gap which was Marconi's transmitter sent waves out into space, and they were picked up at the receiving end. Initially Marconi used a device called the coherer, which was connected to a piece of tape, much like a telegraph tape but this tape was very erratic, it would record static as well as dots and dashes. And so eventually the coherer was replaced by a device called a magnetic detector which was connected to earphones because the human ear is a much more sensitive detector of dots and dashes than a mechanical device can ever be. And so Jack Binns being an accomplished operator would be able to hear the dots and dashes in his headphones and distinguish those from static.

On the receiving end, you put your earphones on and you hear a variety of things: roars, crashes, static, all kinds of stuff. And what you as an operator have to do is figure out which are dots and dashes, which are static, which are interference, and know the difference. And then jot down what you're hearing. And so one of the skills of an operator is being able to hear not just what's a dot and a dash, but skilled operators learned the fist of other operators. They could tell who was sending at what time because they became such adept hearers.

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