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ARTICLE JOHN AMBROSE FLEMING AND THE CENTENARY OF A NOBEL PRIZE “IN SCIENCE IT IS THE TRIFLES THAT COUNT” BHUPATI CHAKRABARTI* n occasionally used English adjective ‘ambidextrous’ describes a person whose both A hands can work with equal agility. In Mahabharata Arjuna was designated as one with that ability. And from our experience we know that it is easier to designate someone either as ‘right handed’ or as ‘left handed’ but not with that adjective. But in the field of Physics we have at least one very well known ‘ambidextrous’ person. Students learn about his left hand rule when the principle of an electric motor is explained to them and then they find that the same scientist rules with his right hand when it comes to explaining of the principle of an electric generator or dynamo. The man responsible for these, John Ambrose Fleming was born one hundred and sixty years ago in 1849. And he was really an ambidextrous scientist who contributed both in theoretical and applied physics with equal aplomb. Not only for his two rules those go by his name but for his immense contributions in the field of radio transmission and radio telegraphy in an active career that spanned for nearly seventy five years. It began in the last quarter of the nineteenth century and continued to the first half of the twentieth century. And probably his most famous and of course most useful invention that where Fleming had a role and this was the Prize that we has completed a century of its existence a few years back did talk about a lot last year during the celebration of is the diode valve. With the electronics ruling the roost of 150th birth anniversary of Sir J.C. Bose for the reasons the technological innovations that we come across in well known. today’s world this is possibly right time that we look back to this ‘first electronic device’ and its colourful inventor The valve came to be known as Fleming valve and Sir John Ambrose Fleming. Moreover this year, 2009 marks now we call it a diode valve while the Americans call it a the centenary year of the Physics Nobel Prize that went vacuum tube. It was in 1904 the British Engineer Fleming to Marconi and Karl Fardinand Braun for their was working as a consultant to Marconi, the Italian ‘development of wireless telegraphy’. This was a work physicist who was at that time took up the responsibility of establishing trans-Atlantic telegraphy. They were actually looking for a receiver for the radio waves and * Department of Physics, City College, Kolkata 700 009 [email protected] Fleming was deeply involved in the work. Since Fleming 112 SCIENCE AND CULTURE, MARCH-APRIL, 2010 and developed what is known as crystal detector that he introduced as a part of the wireless detector. In has to be noted that the name of Italian scientist Marconi appeared in all media and in a large number of conferences and seminars last year (2008) when the world observed the 150th birth anniversary of Sir J.C. Bose. Marconi was not only inspired by the ideas of Sir J.C. Bose on the wireless communication by millimeter waves, he closely followed the works of Hertz, Oliver Lodge and others. He actually took special interest in the subject rightly also worked earlier as a consultant with Thomas Alva gauging the commercial prospect of wireless Edison who discovered thermionic emission in 1883 he communication for which scientists, technologists and of was aware of the effect known as ‘Edison effect’ after the course entrepreneurs were putting up efforts right from name of its discoverer. That definitely helped Fleming to the middle of nineteenth century. Marconi was guided by patent his, nay the mankind’s first electronic device back Fleming in a big way to achieve the reliable transatlantic in 1904. And it was a relatively crude form of what is now wireless communication. Moreover Fardinand Braun’s work known as a diode valve. He took patent of this invention was there to pave the way for first trans-Atlantic wireless in the same year i.e. in 1904 and that invention was came communication. Fleming was senior to Marconi by about to be known as Fleming valve. 25 years and in early 20th century Fleming was an established professor of Electrical engineering. In 1909, The one-way conduction, better known as exactly 100 years back when Marconi won the Nobel Prize rectification was actually discovered by Karl Ferdinand in Physics, he actually shared it with Karl Ferdinand Braun Braun (1850-1918) in 1874. He first found that metal wire but Fleming was not there in the winner’s list. It did hurt contacts on lead sulphide or galena crystals shows very Fleming. The winning of Nobel Prize was in a way was high resistance when current is sent through in one very special for Marconi as he was possibly the first direction while the other direction offers much smaller industrial physicist to get that recognition. He was not resistance. Braun persisted with the research in the field affiliated to any academic institution at that time. Rather Fleming diode valves, 1904-1905 VOL. 75, NOS. 3–4 113 he had his own company and the work he undertook was actually part of his commercial venture. He was, in today’s parlance an entrepreneur par excellence that floated a company in his name, took patents of his work and was quick enough to shift his base from Italy to England just to pursue his goal of achieving the wireless communication across the Atlantic. It is not easy to quantify one single person’s contribution in a particular scientific or technological breakthrough yet it is now acknowledged that Marconi got the inspiration of his work from Sir J.C. Bose while Fleming was among the leaders who saw the execution of the project that may be termed as the ‘trans-Atlantic wireless communication’. Sir J.C. Bose left the research Oscillation valves first employed by Fleming in October, 1904 field of wireless communication well before 1909 and could appreciate Marconi’s achievement in his writings. But Fleming still very much involved in teaching and research in engineering possibly a bit upset as the Nobel Prize also eluded him. Fleming was indeed a very interesting personality. He was a student of Maxwell in 1877 under whom he studied electricity and magnetism at Cambridge. The subject proved to be extremely interesting for young Fleming and he completed his D.Sc. under the great physicist Maxwell who had a very untimely demise in 1879 only at the age of forty-eight. But this brief association with Maxwell kept a deep imprint in the future career of Fleming who developed his lifelong interest for electricity An early model of a Fleming diode valve, 1905 and the related instrumentation. It was the infancy of electric lighting though it was gaining popularity. Fleming in 1881 joined the electric company founded by Edison as a consultant that he continued for next ten years and began to develop different equipment and accessories for electric lighting. This served two basic purposes, one the electric lighting become gradually popular and Fleming came out with a number of important inventions in the field of photometry. The way Fleming worked both at the industry as well as in the academic institution is quite remarkable considering his time. Fleming actually had a keen interest in the subject of electrical engineering. But as one can understand that without the emergence of electricity as a viable and attractive component of our daily life the subject of electrical engineering cannot emerge. That is why Fleming was doing next best option available i.e. Physics. He however had an excellent flare for delivering good quality lecture and he did so in the University College of London (UCL) on his favourite topics related to electricity and its different aspects. Finally in 1885 the UCL asked him to The Fleming oscillation valve, ca. 1910 build up a department with Fleming as the professor. It 114 SCIENCE AND CULTURE, MARCH-APRIL, 2010 Fleming joined the company of Marconi as a consultant in 1899 while he was a professor at UCL. At that time Marconi was trying hard to send transatlantic wireless signals that he finally succeeded in 1901 and now we know it was possible for the existence of ionosphere in the upper atmosphere till unknown at that time. But this signal was not detectable or could be converted into speech, as there was no suitable detector. Fleming while addressing this problem actually came up with the invention of the diode valve. He was a keen observer of the phenomena that used to take place during an experiment conducted in the laboratory. He used to make it a point to look at every small thing critically with the eye of an inventor. The background for this invention is even better expressed in his own words, that shows how as an experimentalist he used to take critical look at the happenings at the laboratory. He said “In 1882, as electrical adviser of the Edison Electric Light Company of London, I was brought into close touch with the many problems of incandescent lamps and I began to study the was a job indeed close to his heart and he did it with a great success and continued in his position for the next forty years. Part of the patent drawing of the first wireless detector to use a An experimental lamp which John Ambrose Fleming used thermionic valve, 1904 VOL.

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