A little ‘light’ reading

Midlothian Science Festival celebrates International Year of Light 2015

UNESCO has designated 2015 as the International Year of Light to commemorate the 150th anniversary of the work of a Scottish scientist who showed that light consists of electromagnetic waves. The scientist was James Clerk Maxwell, a member of the Clerk family of Penicuik Estate, who was born in Edinburgh but spent his childhood on a country estate at Glenlair, near Castle Douglas in Galloway. James Clerk MaxwellHe later attended Edinburgh Academy and the University of Edinburgh where he excelled in Physics and Mathematics. He went on to have a very successful career at Aberdeen University, King College, London and Cambridge University but he remained close to his Scottish roots and always regarded Glenlair as his home. Although he died in Cambridge, he was buried beside his parents in the old kirkyard at Parton, near Glenlair.

His analysis of the experimental work of Michael Faraday was to lead to a unified theory of electricity and magnetism, the theory of electromagnetic waves and the foundation of much of our modern communications technology. Sadly, James Clerk Maxwell died in 1879 at the age of only 48, before his theory could be applied to the generation of radio waves. This was done in Germany in 1887 by Heinrich Hertz who demonstrated wireless communication over a distance of a few metres using what he called “Professor Maxwell’s electric waves”. Surprisingly, he did not see any application for this work but it would be exploited to great effect by Marconi and others …and the rest is history!

Maxwell also did pioneering work on colour perception by the human eye, showing that any colour could be created by combining Red, Green and Blue light in the appropriate ratios. He went on to demonstrate the world’s first colour photograph – of a piece of tartan ribbon. The year was 1861, long before colour film was invented, but he had proved the basic physical principles on which modern digital cameras are based.

sir John Clerk with torchJames Clerk Maxwell is not well known by the general public, even in Scotland. When the IYL2015 was announced in 2014, planning was in place for a range of events, worldwide, to commemorate his work and to help to raise his profile. Howie Firth, Director of the Orkney International Science Festival, suggested that a ‘Maxwell Torch’ or light baton – rather like an Olympic Torch – should be created and that it should appear at all the Science Festivals in Scotland during 2015. An appropriate torch has been designed, built and donated by Mike Stoane Lighting of Loanhead. Its first public appearance was at the Music Hub in Penicuik in March when it was accepted by Sir Robert Clerk, a relative of James Clerk Maxwell. The event was a lecture with music, covering the biography and scientific work of Maxwell, entitled “James Clerk Maxwell – a man of Science, Poetry and Music.”

Since then, the Maxwell Torch has appeared at events all over the country, from the Edinburgh International Science Festival in April to the Orkney International Science Festival in September and it will be appearing again at the Midlothian Science Festival in October.

Harald HaasOne of the highlights of the festival will be the Midlothian Lecture at the Lasswade Centre on Monday 5th when Prof Harald Haas will describe how LED lighting can be used instead of radio to transmit information – a novel application of Maxwell’s work known as Li-Fi.

Dalkeith Kings Park is the venue for another event on Friday 16th, Park in the Dark, which will feature an exhibition and family entertainment based on the theme of light. The Maxwell Torch will be making an appearance prior to a Parade of Lanterns.  We also have some lovely dance sessions at the Lasswade Centre which explore the science of light.

So why should we make such a fuss and commemorate some scientific work that was done 150 years ago? Well, that work was truly brilliant in every sense of the word. Maxwell had the vision and the mathematical ability to show that experimental results available at that time concerning electricity and magnetism were consistent with light being an electromagnetic wave. He calculated the speed at which electromagnetic waves would travel through space and found a value very close to the speed of light which had already been measured experimentally by Armand Fizeau in France in 1849.

Maxwell concluded:

“This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws.”

This has been described as one of the greatest leaps ever made in human thought.

The subsequent applications of Maxwell’s work have brought enormous benefits to mankind, worldwide. We now carry wireless communication in our pockets in the form of mobile phones; we have radio and television broadcasting, worldwide; his work on colour vision is used in digital cameras and colour printers – the list is a long one. On the centenary of Maxwell’s birth in 1931, Albert Einstein said

“His work was most profound and the most fruitful that physics has experienced since the time of Newton”.

So, whenever we watch television, make a mobile phone call or take a digital photograph we should remember the boy from Glenlair in Galloway who would become one of the world’s greatest scientists.

Author: Juliet Ridgway-Tait

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