ERNEST RUTHERFORD
Ernest
Rutherford was born on August 30, 1871, in Nelson, New Zealand, the
fourth child and second son in a family of seven sons and five daughters.
His father James Rutherford, a Scottish wheelwright, emigrated to New
Zealand with Ernest's grandfather and the whole family in 1842. His
mother, née Martha Thompson, was an English schoolteacher, who, with her
widowed mother, also went to live there in 1855.
Ernest received his early education in Government schools and at the age
of 16 entered Nelson Collegiate School. In 1889 he was awarded a
University scholarship and he proceeded to the University of New Zealand,
Wellington, where he entered Canterbury College. He graduated M.A. in 1893
with a double first in Mathematics and Physical Science and he continued
with research work at the College for a short time, receiving the B. Sc.
degree the following year. That same year, 1894, he was awarded an 1851
Exhibition Science Scholarship, enabling him to go to Trinity
College, Cambridge, as a research
student at the Cavendish Laboratory
under J.J.
Thomson. In 1897 he was awarded the B.A. Research Degree and the
Coutts-Trotter Studentship of Trinity College. An opportunity came when
the Macdonald Chair of Physics at McGill
University, Montreal, became vacant, and in 1898 he left for Canada to
take up the post.
Rutherford returned to England in 1907 to become Langworthy Professor of
Physics in the University of Manchester,
succeeding Sir Arthur Schuster, and in 1919 he accepted an invitation to
succeed Sir Joseph Thomson as Cavendish Professor of Physics at Cambridge.
He also became Chairman of the Advisory Council, H.M. Government,
Department of Scientific and Industrial Research; Professor of Natural
Philosophy, Royal Institution, London;
and Director of the Royal Society
Mond Laboratory, Cambridge.
Rutherford's first researches, in New Zealand, were concerned with the
magnetic properties of iron exposed to high-frequency oscillations, and
his thesis was entitled Magnetization of Iron by High-Frequency
Discharges. He was one of the first to design highly original
experiments with high-frequency, alternating currents. His second paper, Magnetic
Viscosity, was published in the Transactions of the New Zealand
Institute (1896) and contains a description of a time-apparatus
capable of measuring time intervals of a hundred-thousandth of a second.
On his arrival at Cambridge his talents were quickly recognized by
Professor Thomson. During his first spell at the Cavendish Laboratory, he
invented a detector for electromagnetic waves, an essential feature being
an ingenious magnetizing coil containing tiny bundles of magnetized iron
wire. He worked jointly with Thomson on the behaviour of the ions observed
in gases which had been treated with X-rays, and also, in 1897, on the
mobility of ions in relation to the strength of the electric field, and on
related topics such as the photoelectric effect. In 1898 he reported the
existence of alpha and beta rays in uranium radiation and indicated some
of their properties.
In Montreal, there were ample opportunities for research at McGill, and
his work on radioactive bodies, particularly on the emission of alpha
rays, was continued in the Macdonald Laboratory. With R. B. Owens he
studied the "emanation" of thorium and discovered a new noble
gas, an isotope of radon, which was later to be known as thoron. Frederick
Soddy arrived at McGill in 1900 from Oxford,
and he collaborated with Rutherford in creating the "disintegration
theory" of radioactivity which regards radioactive phenomena as
atomic - not molecular - processes. The theory was supported by a large
amount of experimental evidence, a number of new radioactive substances
were discovered and their position in the series of transformations was
fixed. Otto
Hahn, who later discovered atomic fission, worked under Rutherford at
the Montreal Laboratory in 1905-06.
At Manchester, Rutherford continued his research on the properties of the
radium emanation and of the alpha rays and, in conjunction with H. Geiger,
a method of detecting a single alpha particle and counting the number
emitted from radium was devised. In 1910, his investigations into the
scattering of alpha rays and the nature of the inner structure of the atom
which caused such scattering led to the postulation of his concept of the
"nucleus", his greatest contribution to physics. According to
him practically the whole mass of the atom and at the same time all
positive charge of the atom is concentrated in a minute space at the
centre. In 1912 Niels
Bohr joined him at Manchester and he adapted Rutherford's nuclear
structure to Max
Planck's quantum theory and so obtained a theory of atomic structure
which, with later improvements, mainly as a result of Heisenberg's
concepts, remains valid to this day. In 1913, together with H. G. Moseley,
he used cathode rays to bombard atoms of various elements and showed that
the inner structures correspond with a group of lines which characterize
the elements. Each element could then be assigned an atomic number and,
more important, the properties of each element could be defined by this
number. In 1919, during his last year at Manchester, he discovered that
the nuclei of certain light elements, such as nitrogen, could be
"disintegrated" by the impact of energetic alpha particles
coming from some radioactive source, and that during this process fast
protons were emitted. Blackett
later proved, with the cloud chamber, that the nitrogen in this process
was actually transformed into an oxygen isotope, so that Rutherford was
the first to deliberately transmute one element into another. G.de
Hevesy was also one of Rutherford's collaborators at Manchester.
An inspiring leader of the Cavendish Laboratory, he steered numerous
future Nobel Prize winners towards their great achievements: Chadwick,
Blackett, Cockcroft
and Walton; while other laureates worked with him at the Cavendish for
shorter or longer periods: G.
P. Thomson, Appleton,
Powell,
and Aston.
C.D. Ellis, his co-author in 1919 and 1930, pointed out "that the
majority of the experiments at the Cavendish were really started by
Rutherford's direct or indirect suggestion". He remained active and
working to the very end of his life.
Rutherford published several books: Radioactivity (1904); Radioactive
Transformations (1906), being his Silliman Lectures at Yale
University; Radiation from Radioactive Substances, with James
Chadwick and C. D. Ellis (1919, 1930) - a thoroughly documented book which
serves as a chronological list of his many papers to learned societies,
etc.; The Electrical Structure of Matter (1926); The Artificial
Transmutation of the Elements (1933) ; The Newer Alchemy (1937)
Rutherford was knighted in 1914; he was appointed to the Order of Merit in
1925, and in 1931 he was created First Baron Rutherford of Nelson, New
Zealand, and Cambridge. He was elected Fellow of the Royal Society in 1903
and was its President from 1925 to 1930. Amongst his many honours, he was
awarded the Rumford Medal (1905) and the Copley Medal (1922) of the Royal
Society, the Bressa Prize (1910) of the Turin Academy of Science, the
Albert Medal (1928) of the Royal Society of Arts, the Faraday Medal (1930)
of the Institution of Electrical Engineers, the D.Sc. degree of the
University of New Zealand, and honorary doctorates from the Universities
of Pennsylvania, Wisconsin, McGill, Birmingham,
Edinburgh, Melbourne,
Yale, Glasgow, Giessen,
Copenhagen, Cambridge, Dublin, Durham,
Oxford, Liverpool, Toronto,
Bristol, Cape
Town, London and Leeds.
Rutherford married Mary Newton, only daughter of Arthur and Mary de Renzy
Newton, in 1900. Their only child, Eileen, married the physicist R. H.
Fowler. Rutherford's chief recreations were golf and motoring.
He died in Cambridge on October 19, 1937. His ashes were buried in the
nave of Westminster Abbey, just west of Sir Isaac Newton's tomb and by
that of Lord Kelvin.
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