GENIUS OF RUTHERFORD

Press, Volume LXXIV, Issue 22376, 13 April 1938, Page 12

GENIUS OF RUTHERFORD

Tribute to Great Physicist

DR. C. COLERIDGE FARR’S ADDRESS

Commemoration Day at Canterbury College

The memory of Lord Rutherford was honoured at the Commemoration Day ceremony at Canterbury University College last evening. Rutherford came to the college on scholarship from Nelson, learned the first principles of scientific study there, and moved on to Cambridge, where his genius and industry carried him to the topmost pinnacle of scientific achievement.

In tribute to his memory, a lifelong friend of Rutherford, Dr. C. Coleridge Farr, a Fellow of the Royal Society and Emeritus Professor of Physics at Canterbury College, gave the Commemoration Day address on the achievements of the great New Zealander and their significance In the history of physics.

“In many respects the lives of the two most distinguished and famous experimental physicists that the world has known have been strikingly alike, Dr, Farr said. “Both Faraday and Rutherford were the sons of blacksmiths; both of them started life under difficult circumstances. Faraday was apprenticed to a bookbinder and was by trade a bookbinder himself. This was not a hopeful beginning from which to carve out a great career, but he attended Sir Humphrey Davy’s lectures at the Royal Institution and kept notes so carefully and bound them up so beautifully that when he went to Davy and asked to be appointed to a post in the laboratory Davy was impressed by what he had done and appointed him to a very junior position, but Faraday never had any university training and very little theoretical training at all apart from what he could pick up. In Faraday’s Steps

tical aims in view. Neither Rutherford nor Faraday paid the slightest attention to possible future utility in any of their work, nor, indeed, I think, does any other man, unless he is embarking upon the solution of a definite economic problem. Faraday’s results have certainly had a most surprising mechanical effect, and it is certain, too, that Rutherford’s work, which opens wide doors for further examination in a scientific way, will also have its own practical influence upon our lives and happiness, though it is too early yet to say what these effects will be. “But already there is one result of inestimable value to us. Rutherford s work was largely concerned with radium and its companion radioactive substances, and it was to him that we owe the analysis of the rays which are given off by these different substances. He showed us how to sift these complicated radiations into simpler components, and from the treatment of malignant growths by one or other of these types of rays, many people suffering from what, till their discovery and examination, were considered incurable cancers, have been cured, and many others have been relieved from pain. The examination of these rays and their analysis was, However, but a very small piece of his activities. The question whether, when their nature was analysed, they would have any utilitarian application, did not, I imagine, even enter his head, and he. like Faraday, left it to others to apply the results of his work to practical questions. “This is not the time, neither is this the place, to go into any detailed account of Rutherford’s researches. At present one has to dig through the publications of the various scientific societies, and that in many languages, to find them fuliy, though the greater number of papers dealing with his investigations is to be found either in the Philosophical Magazine or in the different publications of the Royal Society of London. An account of hia life is at present being written by Professor Eve, and will, it is hoped, be published by .the Cambridge University Press in November, and I imagine that, as is usual with the work of famous scientific men, his ‘Collected Papers’ will also be issued, perhaps as a memorial volume or series of volumes latch But still I may perhaps refer to one or two of these Individual researches. Structure of the Atom

“At that time, however, there was not much theory. Faraday himself laid the foundation of it and Maxwell added the superstructure, I doubt « there were many scholarships in ms day, for he was born In 1791 and none of the provincial universities, were in existence. Rutherford, starting life 80 years later (he was born in 1871) began in circumstances which for that period were almost as difficult. He ■was on© of a large family, and lus parents were not well off and could not give him many educational advantages. Indeed, he started at the tiny little Havelock school, and I understand that there is a pen still sticking in the ceiling of that school — in spite of unimaginative painters, school building inspectors, and others of that sort—which Rutherford threw there as a dart, s , , , “And so these two great leaders'of experimental physics began their careers under much the same conditions in so far as the 80 years which supervened between them permitted similarity. Each owed his life’s work to a fortunate chance. Faraday’s life and therefore the world’s knowledge would have been very different if he had not succeeded in catching the eye of Sir Humphrey Davy; and Ruther-( ford’s chance came through his having allotted to him a scholarship he did not actually' win—the 1851 Exhibition ScholarshiPr-a scholarship which Dr., McLaurln wax . forced to turn down owing to family-etonsideratiotxs. • “Time enough elapsed, since Faraday lived and oiad,,for us tor be, able to see what, the world owes to his researches. I suppose the most striking of his discoveries was. that of the induction of electric! currents, but for 20 years after it was made there were but few practical applications of it. The world was feeling its way in regions previously unknown. To-day it it not too much to say that civilisation stands upon this earth with one of its feet firmly planted upon that discovery, for It is the basis of all our modem progress. Modem heavy electrical engineering—the transmission of electric energy, wireless communication. flying; all are based upon this as a fundamental discovery. “For how many thousands years —or Is it tens of thousands of years?— the world has been creeping up to' tlus, I do not know. The discovery of the induction of electric. currents in 1831 was one of the “trigger" actions which started men’s minds thinking in new directions. Rutherford’s work itself, indeed, depends on Faraday’s discoveries; the. work ot a later generation is built upon the foundation laid by an earlier one. Practical SeeolU “It Is not yet possible to say where Rutherford’s .discoveries will lead us. It Is certainly- not possible to say what practice advantages or applications they may have. It Is neither desirable nor is It necessary to do so. He would be but a poor, and I hope end think, a very unsuccessful sexen- . tifle man who started out on his investigation* with only, or mainly prac-

“I suppose that the paper, -yvhich had the most immediate and .most farreaching effect on* thought and work was ; one of perhaps two. Either it was one in which Rutherford and Soddy proposed, as an-, explanation of the radiations of the radioactive substances, that the radio-active elements were creaking down into other more simple substances, that the atom, that is to say, of one substance, was changing into the atom of another, and that the radiations it was emitting were the evidences of that change; or else it was a paper published about 1911, giving a picture of the actual structure of an atom Itself. The first of these two papers opened quite new ground, for before this everybody had regarded matter of different sorts,- for example, copper and lead, as made so from the beginning. “The atoms of these substances, it was thought—the smallest fundamental parts of each one of them were identical with the other atoms of the same substance —were all of them cast in the same mould and not capable of further subdivision or change. Indeed, the word ‘atom’ means indivisible or undivided. But here was another picture, for if the radio-active atoms were atoms in process of breaking down, well, it showed that they were divisible and were structures of great complexity. This disintegration theory fell upon the ears of an astonished World. “One doesn't get from the bottom of a ladder to a point well up it without climbing up the intermediate rungs, and so it was that the passage from this breaking up theory to a picture of atomic structure took a considerable number of years. The activity of both Rutherford and his Students was at this time, from 1900 to 1910, most remarkable. Papers giving an account of work done and knowledge gained poured out at a tremendous rate, both from Montreal, .where Rutherford first lived, and afteriwards from Manchester, to which he moved.

“But as I have said, perhaps the next great epoch-making event was the publication of a paper giving his ideas of what an atom was like. Others, particularly J. J. Thomson and Nagoaka, had tried to formulate views of atoirilc , structure, but neither of their pictures stood up to the light of the searching Inquiry of scientific investigation. mainly that of Rutherford and his school; and it was not until the publication of Rutherford’s paper that this problem became nearly solved. , “The atoms of all substances turned out to bef vast electrical structures of great complexity—a complexity which depended upon the particular substances, gold, lead, mercury, copper, arid involved vast electrical structures built in the tiniest of universes, the universe' of the ultra-ultra-ultra-, microscopic. These structures were vast as compared with the sizes of the component parts Into which some of them were disintegrating, but tiny as compared with even the smallest of those measures by which the ordinary man la accustomed to conceive “It is now, I hope, well known to most people that' Rutherford’s structure wss one built on similar lines to the solar system and consisted of a nucleus, the dominating centre of tne atom, surrounded by a ® of planetary electrons. This Picture, promulgated by him in 1911, withstood the attacks of many scientific men mid much experimentalising, and ha» emerged without: much change as tne conception of atomic strutture held to-day. Much work, many taverfigations. and great advances, to which time and occasion do not Permit me to refer, resulted from this 1911 work of Rutherford's, but there are perhaps only one or two more to which I can> even refer. Breaking the Atom “With the knowledge experience gained from 20 years of experimental work with radio-active. substances Rutherford decided ™£^i try and smash the nucleus of »tem (he. chose nitrogen); by ih^.To/smsrih/ ,it - ho must hit it fair arid square, and of aU things U P till 1 then it was the most minute thlng I known but twa The shsnnes of hitting

it lair and square were almost less than infinitesimal. . . “He calculated that if he aimed at it he had about one chance in one thousand million ol hitting it. But he had available a machine-gun which was ejecting an enormous number of missiles a second and at a speed of 12,000 miles a second, and so he used this substance and _ once m about one thousand million times he hit the nucleus and broke it. To read of a performance like this alter .it is an accomplished fact is a fascinating story, but it does not, told as he told it, seem so difficult. To do a thing a second time after it has once been done is generally easy but this changing of one atom into another had been a problem that had been before the ■world from the dawn of history. “The problem of converting one element into another was that of the old alchemists, but theirs were mostly sordid motives. It has been the subject of many futile experiments from the time of Caligula, at any rate, until now. The trouble with these old people is that they did not know the problem they were up against. Rutherford did, and, moreover, he had this advantage over the old people: his motives were of the purest, theirs were dominated by considerations of profit. He not only was the Master Alchemist—the first man artificially and deliberately to convert one element into another, but he also, as I have said previously, showed that throughout the flow of time Nature herself had been automatically doing this very same thing, though not in the same way, and examples of it were to be seen in the heavy or radio-active elements. “It was not perhaps the actual conversion of one element into another, of nitrogen into oxygen and hydrogen, or is it carbon and hydrogen, interesting and most important though that was, which made this. bombardment experiment so far-reaching; it was the fact that the method of bombardment first used by Rutherford afforded another means of studying the structure of even the nucleus of an atom itself. A Single Course

“Before Rutherford’s time we had thought that an atom had no structure. Yet here he was. 17 or 18 years before the end of his life, actually studying the internal structure of something whose volume was one thousand million million times smaller than even that small thing. And for these last 17 or 18 years of his life, now most unfortunately brought to its close, he has been actually * dismembering the very nucleus of an atom itself and throwing light upon its makeup. “He and his band of research students at Cambridge have dug deeply into the very core of the atom, and it is quite true to say that we now know a great deal more of the building stones and energy levels of the nucleus of an atom than we knew of the atom itself 30 years ago or even 26 years ago. Indeed, 30 years ago men only suspected, but did not certainly know, that the atom itself had any structure. Now, owing to the work of Rutherford and his school, we know that its core or nucleus also has structure, and of a not very dissimilar character though the component parts are different. “With the exception of an abrupt change at the outset of his life, Rutherford has followed one line of research throughout his scientific career. He has, as it were, followed along a fundamental branch of the tree planted 80 years earlier by Faraday. Out ot this fundamental branch, as it grew under his care and development, many side shoots started to grow, and some of them might perhaps have looked even more alluring and stronger in their early growth than the branch he was following. A less far-seeing man might easily have been led oil into these interesting side issues, but he has left them alone, having seen them budding vigorously. These subdevelopments have always been taken up and carried on by others, and some of them are now considerable branches, from which still other branches are starting to shoot. “About 28 years ago, at a time when Sir J. J. Thomson was just completing 23 years’ tenure of the Cavendish Chair of Physics at Cambridge, a history of Ihe Cavendish Laboratory covering the regimes of Maxwell. Lord Rayleigh, and so much of Thomson’s own tenure as was then completed, was written, and it was said then that it might be doubted whether any post in the world’s history had ever been held by three men of such supreme and varied genius. It was not until six or seven years later that Sir J. <i. Thomson retired and became Master of Trinity, and Rutherford succeeded him in the chair. If when this History was written the question was only a little doubtful, there can be no doubt whatever about a larger and more embracing statement of the same kind to-day, and it can be said without any hesitation whatever that there is no post in the British Empire, or indeed in the world, which has been held by four men of such supreme and varied genius as Maxwell. Rayleigh, Thomson. and Rutherford."