Marsden, Ernest

views updated Jun 27 2018

MARSDEN, ERNEST

(b. Rishton, near Blackburn, Lancashire, England, 19 February 1889; d. Lowry Bay, New Zealand, 15 December 1970)

atomic physics, administration.

Ernest was the second of the five children, including four sons, of Phoebe (Holden) and Thomas Marsden, a weaver, later a draper and hardware dealer. He won scholarships to Queen Elizabeth’s Grammar School in Blackburn and in 1906 to the University of Manchester, where he took the honors course in physics under Arthur Schuster and supplemented his scholarship by teaching.

In 1907, under Ernest Rutherford’s influence, Marsden became interested in radioactivity. His most important research work was done as an undergraduate in Rutherford’s department at the University of Manchester. Assisting Hans Geiger by counting α particles fired down a glass tube, he found that they were diffusely reflected from the tube walls. On Rutherford’s suggestion he found that a particles are scattered through large angles from a metal surface, the scattering varying with the atomic weight of the metal. From these results (1909) Rutherford conceived the nuclear theory of atomic structure (1911). Marsden completed his B.Sc. in 1909 with first-class honors, became a Hatfield Scholar at Manchester, and was then appointed lecturer in physics at East London College (1910). Returning to Manchester as John Harling Fellow (1911-1912), he continued with Geiger experiments that tested Rutherford’s predictions and confirmed his conception. Marsden took part in this series of experiments, since recognized as some of the most beautiful ever performed, when he was only twenty-four years old. He Succeeded Geiger as lecturer and research assistant (1912-1914) and was awarded the degree of D.Sc. in 1914.

In 1913 Marsden married Margaret Sutcliffe of Colne, Lancashire (d. 1957); they had a daughter and a son. In 1914, on Rutherford’s recommendation, he was appointed professor of physics at Victoria University College, Wellington, New Zealand, succeeding T. H. Laby. Soon after arriving in New Zealand early in 1915, he joined the territorial forces and volunteered for overseas service with the Divisional Signals, but was transferred to the Royal Engineers sound-ranging unit in France, perfecting techniques for directing artillery fire on enemy batteries. He was twice mentioned in dispatches and awarded the Military Cross (1919).

After the war Marsden resumed his university post, showing his gift for getting what he wanted by obtaining a new physics building, and always pursuing many extramural enthusiasms. “The exhilaration and excitement,” he claimed,“are always in the chase—the conclusion is invariably an anticlimax.” He believed the secret of staying enthusiastic about one’s work was to change jobs every decade. In 1922 he became assistant director of the New Zealand Education Department, pursuing his scientific interests in his spare time. In 1926 he assisted Sir Frank Heath, who was invited to advise the New Zealand government on the application of science to industry.

As a result of the Heath Report (1926), the government established a Department of Scientific and Industrial Research (DSIR) with Marsden as permanent secretary. He tackled the new job with enthusiasm, informality, impatience of red tape, and a warm feeling for people. The new department was created by consolidating physical science units from other state departments (Dominion Observatory, Dominion Laboratory, Geological Survey, Meteorological Service), but New Zealand’s most urgent needs were biological, to serve agriculture and pastoral farming. Marsden persuaded the wheat, dairy, wool, tobacco, and hops industries that cooperative research was worthwhile and practical, establishing, with their financial support, research associations to serve their needs and interests. Plant research and soil bureaus were established; other units worked on entomology, fats research, plant chemistry, geophysical exploration, and physical testing. Marsden played a very personal role in promoting these agencies.

Although set back by economic depression in the 1930’s. Marsden remained to experience the challenge of the first Labour government (1935), which increased science funding. The DSIR played a vital part in World War II in the areas of munitions production, import substitutes, dehydrated foods, and submarine detection. Marsden trained in radar production at Bawdsey Manor, England, returning to New Zealand to promote the local manufacture of radar sets used in the Pacific before United States production took over. In 1943 a chance meeting with James Chadwick and Mark Oliphant in Washington led to ten young New Zealand physicists’ participating in the early years of atomic energy development.

Marsden was the right man to establish New Zealand’s DSIR on a liberal basis of both basic and applied research, but for the postwar period he believed he was not the right man. Retiring from DSIR he became scientific liaison officer in London (1947–1954), representing New Zealand at conferences and promoting renewal of oil prospecting and an iron industry from magnetic irons and ores. He delivered the Rutherford Lecture in South Africa just prior to retiring in June 1954. He continued to work for science in retirement, promoting New Zealand’s participation in International Geophysical Year (IGY), Antarctic exploration, use of geothermal energy, and petroleum investigations that led to a gas-condensate industry. His main interest was in the health hazards of radiation, both natural and man made activities. In 1958 he married Joyce Winifred Chote of Wellington, who became his constant companion and assistant in such retirement interests. They traveled widely for meetings and research, and visited Taiwan, where Marsden advised on scientific development. In 1966 he suffered a stroke, but retained an interest in science although confined to a wheelchair.

Rather short in stature, Marsden had a neat, brisk figure, expressive eyes, and a penetrating mind. His voice retained a Lancashire intonation. He enjoyed good health, was genial, puckish, and full of fun, and had a zest for life and for science. His contagious enthusiasm inspired others, who were stimulated to do their best. He could readily communicate with laymen, children, and the media. He liked routine in his life, claiming that this saved the mental energy of constantly making unimportant decisions. He was gregarious and became an active member of the Rotary Club.

Ernest Marsden was appointed CBE (1935) and CMG (1946) and was knighted in 1958. His contribution to the Allied war effort won him the United States Medal of Freedom (Bronze Palms). He was a Fellow of the Royal Society of New Zealand (1921) and of the Royal Society of London (1946) and received honorary degrees from Oxford and Manchester universities and from Victoria University of Wellington.

BIBLIOGRAPHY

I. Original Works. Marsden owes his reputation as an atomic physicist to about twenty papers, the majority dealing with α particles, mostly written jointly with H. Geiger, T. Barratt, C. G. Darwin, and others, between 1909 and 1915. These and other publications are listed in the memoir by C. A. Fleming in Biographical Memoirs of Fellows of the Royal Society, 17 (1971), 463–496. His later papers, reports, articles, and lectures cover a wide interdisciplinary spectrum, reflecting the busy life of a scientific leader and administrator whose interest in Rutherford and in radioactivity persisted. His letters and other papers are in the Alexander Turnbull Library. Wellington.

II. Secondary Literature. Sir Ernest Marsden 80th Birthday Book. P. Van Asch et al., eds. (Wellington. New Zealand, 1969), includes personal anecdotes and tributes to his career and achievement. See also the biographical memoir by F. R. Callaghan in Proceedings of the Royal Society of New Zealand, 99 (1971), 111–125. For background on the history of experiments that supported the nuclear atom, see J. L. Heilbron, “The Scattering of Alpha and Beta Particles and Rutherford’s Atom,” in Archive for History of Exact Science, 4 (1968), 247– 307.

C. A. Fleming

Complete Dictionary of Scientific Biography

Marsden, Ernest

views updated May 18 2018

Marsden, Ernest

ENGLISH PHYSICIST
Ca. 1888–1970

Ernest Marsden studied at the University of Manchester under Ernest Rutherford and Hans Geiger. Although a physicist, he would help elucidate something of value to all chemists: the internal structure of the atom. This was accomplished by observing the path of α -particles in Rutherford's famous "gold foil experiment," in which it was really the human eye, pressed to a short-focus telescope for hours on end in a thoroughly darkened room, that was the detector.

According to Rutherford, Marsden, a twenty-year-old undergraduate, became involved after Rutherford and Geiger decided that Marsden should begin research work. Rutherford thought that Marsden might be able to discover if α -particles could be scattered through a large angle. Geiger and Marsden spent 1909 in the "gloomy cellar" of the physics laboratories at Manchester, watching for the little sparks that announced the unlikely recoil of α -particles. About 1 in 8,000 did, and this result, published in 1909 as "On a Diffuse Reflection of the α -Particle," formed the basis for Rutherford's nuclear model of the atom and the discovery of the proton.

Geiger and Marsden continued to study the deflection of α -particles, and in 1913 (after observing over 100,000 scintillations at a rate of 5 to 90 per minute) correlated nuclear charge with atomic number . In 1914 and 1915 Marsden continued to study the impact of α -particles on matter; these experiments led to Rutherford's 1919 fortuitous attainment of the alchemist's dream: the artificial transmutation of the elements.

Marsden returned to his native New Zealand in 1915 where, on Rutherford's recommendation, he was appointed professor of physics at Victoria University in Wellington. He held various academic and governmental posts until his retirement in 1954. The national fund for the support of science in New Zealand was renamed the Sir Ernest Marsden Fund in his honor.

see also Geiger, Hans; Rutherford, Ernest.

Mark A. Pichaj