Transmission
One of my favourite physics demonstrations is one that shows how sound can be indirectly transferred from one place to another using a beam of light. The speaker of something that plays music is disconnected and instead connected to a light emitting diode. That is then made to flicker, faster than we can see, by the electrical signal which would have vibrated the speaker. If the flickering light is pointed at a photocell, something that detects light, and that is connected to an amplifier and then a separate speaker, a very distorted sound is heard. If something to guide the light, such as a length of fibre optic cable, is placed between the flickering light and the detector, then the quality of the sound played improves and the distance between them can be made much bigger. It is all rather magical when the sound comes out of the speaker even though it is not connected to the source of the music by any wires.
If you are on the School site on a dark winter’s evening and look towards the south west, you could almost be forgiven for thinking that you are in Central Paris and seeing double. Why?... well because there in the distance are the Droitwich radio masts with bright red warning lights on the top.
Standing over 200 metres high, two thirds the height of the Eiffel Tower, and 90 years old, the masts were originally the world’s most modern long wave radio transmitters. They helped transmit both BBC radio programmes and, in the Second World War, coded messages for the French Resistance. Radio, like light, is, as you will know, an electromagnetic wave and so it can travel though nothingness very quickly, carrying a signal – a message if you like. Of course, the key is making sure that the message is transmitted clearly, in the right direction, well received and then converted into a useful form…just like the sound which eventually comes out of the speaker in the demonstration I described.
We have come a long way since 1901, when Italian physicist Guglielmo Marconi successfully sent the first radio transmission across the Atlantic Ocean. Despite detractors who believed the curvature of the Earth would limit transmission to 200 miles or less, Marconi’s Morse-code signal transmitting a message, which amounted to just the letter “s”, travelled over 2,000 miles from Cornwall, England, to Newfoundland, Canada. The letter S, which was three Morse code dots, represented 3 bits, or 3/8 of a byte. Today it is thought that nearly 500 exabytes of data are electronically transmitted each day around the world - that’s 5x1020 bytes, compared to Marconi’s fraction of a single byte, and you will be all too aware of the various data you receive in a whole host of different ways all the time.
So why am I saying all this? Well, one of the most basic forms of communication between humans is talking and listening. Someone speaks, we hear the sound and information is transferred; indeed, from the moment we were born we started absorbing language and other communication cues. However, there is so much more to effective communication than that and particularly to listening: if hearing is the passive intake of sound, listening is the active, intentional process of understanding and interpreting what we hear – what the person transmitting the information really wants us to take from them.
In the busyness of a typical day, it is hard to be a good listener. We may have other things to do or there may be all sorts of other distracting noise around us. However, from time to time, listening really well can be vital: giving someone our undivided attention, blocking out peripheral noise and actively engaging with what they are saying. By doing that we let the person know that what they are telling us really matters, through the words that come from their mouth but also through their emotions, body language and so on. How they are acting may be at least as important as their spoken words.
The author Mark Twain said, the right word may be effective, but no word was ever as effective as a rightly timed pause and perhaps that is worth reflecting upon in the modern world where we have such a rapid exchange of data; all those bytes zipping around the Globe all the time. However, for us as humans, communication is more so much than an exchange of data – more than the transmission and reception of a wave, radio, light or sound. The challenge is for us to pick up on the other things, the emotions that go with the words, indeed sometimes it isn’t what a person says but rather what they don’t say which tells more than their words. That can be hard to hear, but we do need to try to listen well.