Noise

Music ought to be but not always is the epitome of wanted sound. In contrast, according to Wikipedia, noise is any unwanted sound. But that cannot always be true.

In most cases noise is not only unwanted but it is also impossible to eradicate. In electronics, noise it is that "hiss" you hear from the speaker even when no music is playing. It is most likely thermal noise and is caused by the random fluctuations of electrons. Every resistor (and an electronics circuit has many) must exhibit thermal noise. The analog in hearing is the hiss that young ears can just about hear due to Brownian motion of air molecules hitting the ear-drum. The only way to eradicate either example of noise is to reduce the temperature to absolute zero but for most of us this is impractical. Much effort is devoted in electronics to minimizing noise or to extracting the wanted "signal" from the inevitable noise "floor". Because it is unwanted, "noise" by definition carries no information. Whereas "signal" by definition most decidedly does carry information. As an electronics engineer I suppose that a good part of my life is spent fighting noise in order to extract signal.

Because we are not used it, total silence can be unnerving. Personally I like it to be quiet. That is one reason why I like living in the country and to do stuff like climbing mountains. Although I dislike man-made noise I love to hear the wind, rain or sea. Some people like to imitate such sounds to help them sleep.

My son and his family have recently moved from the USA to live in Ireland. His girls apparently are so used to noise that they cannot sleep without a noise machine and so they brought one with them. Having suffered the inevitable from plugging it into 230V mains I had opportunity to open it up and discovered with surprise that it consisted simply of an electric fan (so I replaced the motor).  Surprise, because the same thing could have been achieved with some simple electronics and I reckon the manufacturing cost might be and certainly the running cost would be less. To think that they are paying good money for electricity to generate noise which the majority of us are trying to eradicate!

Television Centre

Back in the days of analogue TV the video electrical signal was distributed via coaxial cable. Simplistically, the blood, sweat and tears of a TV production was sent to the transmitter and thence to its millions of viewers via such a cable. In a tea-time discussion when I was working for the BBC the philosophical question was raised - what if the transmitter were replaced by a 75-ohm resistor? Television Centre with its coaxial cable output would be none the wiser. In this way the highly ordered signal that conveyed and thus was the essence of this production would be all "used up" or dissipated in that resistor. Which is kind of the inverse of a resistor generating thermal noise.