Professor Peter S. Excell, Head of School of Computing and Communications Technology
It used to be the case that students of electrical and electronic engineering (and often also of physics) would groan at the mention of “Maxwell’s Equations” – deceptively brief but densely compressed statements of the behaviour of electric and magnetic fields that they all knew were important, but since they rarely needed to use them there was a natural reluctance to gain a full understanding of them.
The speaker is a person in the classic British “no good at maths” mould, who nonetheless appreciated that there was something significant in Maxwell’s Equations and who, through the accidents of a varied career, came to a need to get his head around them. Combining the best explanations to be found in textbooks with insights of his own, he feels that he reached relatively intuitive explanations, although as they still required several hours of lectures to present fully, only a rather general review can be given in a short lecture. Nonetheless, an attempt will be made to explain them in simple terms, appropriate to the specific audience.
The equations are significant because they predicted, almost out of the blue, the possibility of radio transmission of information: we take this for granted now, but the idea of sending invisible messages that can pass through walls, bend over hills and travel around the earth was mind-boggling at the time – and really should still be so today. The story of radio, itself very intriguing, will be reviewed, covering Maxwell, who discovered the principle, but couldn’t do anything with it; Hertz, who demonstrated radio waves, but died too young to exploit them; and Marconi, the “idle rich kid”, who became fired with a passion to turn them into a valuable facility for mankind. Others mentioned will include earlier pioneers like Faraday, Ampere and Coulomb, and Marconi contemporaries such as Oliver Lodge, Jagdish Bose, and the inventors of the radio valve.
The story will be brought up to date with consideration of
the massive changes resulting from the availability of cheap computer chips
(notably the development of mobile phones), and a discussion of where things
are going in the future.