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Susan Douglas on: People's Perception of Wireless
Susan Douglas Q: At first, how did people generally perceive wireless?

SD: You know, whenever anybody talks about radio, they use the word miracle, and we see the word miracle used a lot at the turn of the century and then again in the 20s. And to us, the word miracle has become so evacuated of meaning. We use it to describe mayonnaise, right? So that it's hard for us to really grasp that this was miraculous. People were used to seeing wires strung up everywhere to transmit communication. Here, there was nothing. And people regarded this with great awe and reverence and mystery, and it really seemed utterly miraculous to them that somehow through the air communication could travel.

Q: How did this mysterious technology work, in simple terms?

Wireless is based on the principle that rapid changes in electric and magnetic forces send waves spreading through space. One way you can generate such a rapid change is through a spark, and that's what Marconi used. He used a device called a spark gap, and the spark gap produced high voltage alternating current, which indeed sent waves out into space. Now, what he did was connected this to a telegraph key, and he sought to moderate the spark gap emissions by sending short bursts of energy--those were dots--and long bursts of energy--those were dashes. Now, on the receiving end, you had to be able to pick these signals up. Marconi was a wonderful technological revisionist. He borrowed lots of different components from different inventors and put them together in a system that worked. On the receiving end, he borrowed a device called the coherer, which was filled with shavings of metal filings. When the electromagnetic waves, the radio waves, hit the coherer, these filings cohered, hence the name, and they allowed a current to pass through, and so you'd get the signal. Then a little tiny hammer tapped the coherer, knocked the coherence out of the filings, and so they were ready to pick up the next incoming signal. As you could imagine, this was a rather slow and tedious method of reception, but it did work.

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