Lecture 5 - But electrons aren't coloured!
It is not very difficult to grasp the idea that an electric signal can be made to follow the changes of physical quantities such as the pressure of sound waves or the brightness of different parts of a scene. The relationship can be quite simple; a large signal can represent a high pressure or a bright light, and a small signal can represent a low pressure or a dim light. But how can an electric signal describe a sensation like colour?
The various colours w e see around us are certainly different but, whatever the difference is, it does not readily fit into the 'large' and 'small' type of description. If we are to use electric signals to convey accurate information about colours, we need first to know how to analyse colour in terms of quantities that can be measured. Electric signals can convey accurate information of measured values and with a knowledge of these the correct colours can be reproduced at the receiving end.
About the 1972 CHRISTMAS LECTURES
In his 1972 CHRISTMAS LECTURES, Geoffrey G Gouriet explores the past, present and future of radio communications, and the science that lies behind it.
Radio waves are all around us, continuously being produced and received through man-made devices enabling us to connect with each other and communicate information. Geoffrey Gouriet, through the course of six Lectures, takes us on a journey through history from the first telephone to the 'Viewphone' and with the aid of exciting demonstrations, he explains how devices in our house like the TV translate broadcasted signals into moving pictures.
Gouriet begins with an introduction to electromagnetic waves and the principle behind it as well as how electricity can be used to transmit information.
We then learn how we can get rid of the wires and transmit information through the 'ether' using radio waves and utilizing the layers of the Earth's atmosphere to reach distant locations; the basis of radio and TV broadcasting.
Finally, Gouriet demonstrates how TVs and radios work and how the broadcasted signal is translated. In his last lecture, he gives us a 'vision of the future' outlining how different technologies were currently (then) in development and he even sets up a live broadcast using small dishes from within the lecture theatre.