Lord Ernest Rutherford of Nelson (1871-1937)

 

 

The creator of modern atomic physics and forerunner of the nuclear age, one of the greatest scientists of the twentieth century. Awarded the Nobel Prize in Chemistry in 1908 and a baronetcy, choosing the title Baron Rutherford of Nelson, in 1931. In the words of Einstein, "a second Newton". The man who "tunneled into the very material of God": inventor, experimenter and Nelson farm boy.

 

Rutherford’s strengths as a scientist are legion. A prolific, practical inventor and scientific theorist whose ideas were based on rigorous experimentation; one of the original "demo or die" scientists; turning conjecture into fact. He attributed his willingness to experiment and find unorthodox solutions to his hardscrabble background in rural New Zealand: "We don’t have the money, so we have to think".

 

Three Discoveries

 

Ernest Rutherford’s three major discoveries shaped modern science, created nuclear physics and changed the way that we envisage the structure of the atom today.

 

Rutherford’s first discovery was that elements are not immutable, but can change their structure naturally, changing from heavy elements to slightly lighter elements. This led to him being awarded the Nobel Prize for Chemistry in 1908, at the age of 37, for his work on the transmutation of elements and the chemistry of radioactive material.

 

His second discovery, the nuclear model of the atom, became the basis for how we see the atom today: a tiny nucleus surrounded by orbiting electrons.

 

He built on this discovery for his third great achievement, the splitting of the atom, making him, as John Campbell says in his biography of Rutherford in The Dictionary of New Zealand Biography, "the world’s first successful alchemist".

 

Counting The Beats

 

Ernest Rutherford was born in Brightwater, near Nelson, New Zealand, in 1871, the fourth child and second son of 12 children, to James Rutherford, a mechanic, wheelwright, engineer, flax-miller and farmer and his wife, Martha Thompson, a school teacher before her marriage. Both parents were keen that their children gain an education, and were supporters of the small local schools where Ernest and his brothers and sisters began their schooling. Martha ensured the Rutherford children completed their homework with the dictum, "All knowledge is power."

 

From an early age Ernest was distinguished at school for his arithmetical abilities and his scientific curiosity, both qualities encouraged by his early teachers at the local Nelson schools, Harry Ladley at Foxhill and later by Jacob Reynolds at Havelock School. Reynolds gave extra lessons in Latin and algebra for the local children of above average ability, including Ern and Jim from the Rutherford clan. Ernest's early education, gained at school, from his family and from exploring the local farms and countryside with his siblings, awakened his interest in science and the keen skills of observation that are essential for all scientific minds. A school science text-book told of a method for determining the distance of an enemy's canon, a method which Ernest adapted to local surroundings during an electrical storm at Foxhill, as Eugene Grayland recounts in a reconstruction of an anecdote from Ernest’s childhood in Famous New Zealanders:

 

"James Rutherford, who had got out of bed to check on the storm, was surprised, more so when he heard his son talking to himself softly."

 

‘Ernest, what’s up, my boy?’ he called out.

 

‘I’m counting,’ the boy called back.

 

‘Counting?’

 

There was a rumble of thunder which shook the house.

 

‘Yes. If you count the seconds between the flash and the thunder clap and allow 1,200 feet for each second for the sound to travel, you can tell how close you are to the storm centre.’ "

 

Appropriately, Ernest's first recorded illicit experiment was a canon constructed from the brass tube of a hat-peg with a marble for a ball and a dose of gunpowder to ignite the device. Not the best example of Rutherford's experimental savvy, the resulting explosion failed to hit the target twenty metres away, but succeeded in destroying the structure.

 

The Rutherfords were a close knit family, gathering around the family piano to sing songs; forging a farming life with few amenities in a still isolated and rugged landscape. Though at Havelock two of Ernest’s brothers drowned in a childhood accident and another brother died as an infant, the life of the Rutherford siblings as the family moved around the countryside was also filled with the curiosity-satiating distractions of growing up in the New Zealand outdoors. The stimulus of farm-life: poaching eggs from bird-nests, orchard raiding, swimming in the Wai-iti river, shooting Kereru pigeons fat from feeding on berries, calculating the level for storage ponds at the flax-mill.

 

Making enough of a living to feed the family was a struggle at times. At Foxhill, James Rutherford ran a farm and flax-mill, and at Pelorus, where the family moved in 1883, he ran another flax-mill and in 1885 turned to saw-milling, manufacturing railway sleepers for the Government. However due to an economic downturn his contract was cancelled (while he was recovering from an accident which left him with five broken ribs) and he had to leave the family to look for new opportunity in the North Island. He founded a steam driven flax-mill in Pungarehu, Taranaki, employing twenty people, where he moved the family in 1888.

 

In the school holidays Ernest busied himself with farm chores, helping out at his father’s farm or mill. Ernest distinguished himself from his earliest days at school, but it took two attempts for him to win an education board scholarship to higher education, following his older brother George to Nelson College. For children of less than wealthy parents these were one of the few options available with which to obtain further learning. Ernest attended Nelson College as a boarder for three years, and came under the tuition of the master William Littlejohn, who taught him mathematics and elementary science. In addition to his academic prowess in his final year he was also head boy, dux, and played in the rugby First XV team as a forward.

 

He topped his class in every subject in his final year and won one of ten nationwide Junior Scholarships though again only after sitting the exam for a second time. In 1890 he enrolled at Canterbury College, University of New Zealand (now The University of Canterbury). At Canterbury College he continued to play rugby and took part in the student Dialectic Society (a debating club) and the Science Society.

 

Early Experiments

 

In 1892 Rutherford completed a Bachelor of Arts degree from Canterbury College and won the only Senior Scholarship available for mathematics in New Zealand. This made it possible for him to return to university for an honours year, completing a Master of Arts with double first class honours in mathematics and in physics.

 

At Canterbury he was taught by Professor Alexander Bickerton, whose "genuine enthusiasm for science gave a stimulus to me to start investigations of my own" as Rutherford would credit later. It was in 1893 that Rutherford's talent for original experimentation and research began to manifest itself: a penchant for creating innovative experiments to solve problems. The findings in his first year's research were based on his invention of a machine that could measure time differences of up to one hundred-thousandths of a second and with it he demonstrated that it was possible for iron to be magnetized by high frequency currents. In 1894 Ernst completed a Bachelor of Science in geology and chemistry and in 1895 was awarded an Exhibition of 1851 Science Research Scholarship (but only after the top-ranked candidate withdrew). Ernst elected to work as a research student at the Cavendish Laboratory, University of Cambridge, under Professor J.J. Thomson who was studying the conduction of electricity in rarefied gases, which led to Thompson's 1897 discovery of the electron, the first object discovered that was smaller than an atom. At Nelson College and Canterbury College, fostered by Bickerton, Ernest had been a merely excellent student, but it wasn't until the move to Cambridge on a scholarship designed to benefit young graduates from the outposts of Empire (Rutherford was amongst the first "foreign" students to be admitted to Cambridge, that is, those who had not been through the Cambridge undergraduate system) that his particular gifts were to be fully recognised. Family anecdote recalls that Ernest was on the farm working when he received news of the scholarship: "That's the last potato I will ever dig" he remarked.

 

Cambridge, McGill, Manchester

 

Once in Cambridge he amazed Thomson with his enthusiasm, tenacity and fresh approach. As Campbell has written, Rutherford went to Cambridge with a reputation as an innovator and inventor, and distinguished himself in several fields, initially by divining the electrical properties of solids and then using wireless waves as a method of signalling: "Rutherford was encouraged in his work by Sir Robert Ball, who had been scientific adviser to the body maintaining lighthouses on the Irish coastline; he wished to solve the difficult problem of a ship’s inability to detect a lighthouse in fog. Sensing fame and fortune, Rutherford increased the sensitivity of his apparatus until he could detect electromagnetic waves over a distance of several hundred metres. Thomson [...] quickly realised that Rutherford was a researcher of exceptional ability and invited him to join in a study of the electrical conduction of gases. The commercial development of wireless technology was thus left for Guglielmo Marconi."

 

Rutherford’s advances in the study of radioactive atoms (most notably discovering that two different emissions, named alpha and beta rays, emanate from radioactive atoms) and his genius for experimentation secured his reputation, even compared to his brilliant mentor Thomson. In 1898, at the age of 27, Rutherford moved to McGill University in Montreal, where he was offered the position of Professor of Physics.

 

The McGill years, from 1898 to 1907, were significant for two major developments. Firstly, Rutherford was finally on a secure enough financial footing to marry his long-time fiancée Mary Georgina Newton (the daughter of Rutherford’s landlady in Christchurch, a prohibitionist called Mary Newton who was prominent in the movement which saw the women of New Zealand granted the vote from 1893). Rutherford and Mary were married in 1900 in Christchurch. Their only child, a daughter Eileen, was born in 1901.

 

Secondly it was at McGill that he made the first of his three major discoveries. Assisted by chemist Frederick Soddy, he unravelled the mysteries of radioactive atoms. Going against a popularly accepted belief that elements were immutable (as the derivation of the word atom implies: from the Greek tomos, to cut, and a meaning not; therefore something unsplittable - a conceptual billiard ball), Rutherford showed that some heavy atoms spontaneously decay into slightly lighter, and chemically different, atoms. His book on this subject, Radioactivity, was published in 1904, followed by others in 1906 and 1930. It was this discovery and his work on the chemistry of radioactive materials, that led to him being awarded the Nobel Prize in Chemistry in 1908 for his "investigations into the disintegration of the elements, and the chemistry of radioactive substances."

 

While at McGill Rutherford also developed a range of applications, such as one for measuring vibrations caused by streetcars and one for allowing trains to signal to stations using wireless telegraphy. Much of the apparatus he developed for his research at McGill is today housed at McGill's Rutherford Museum.

 

In 1907, Rutherford was lured back to England, at the age of 36, to become Professor of Physics at Manchester University.

 

Dissecting The Atom

 

In 1907 Rutherford began a debate with physicist Antoine Becquerel on how alpha particles, reacted when they were ejected from radioactive material. Discovering that alpha particles tended to bounce off air molecules, he surmised that there had to be something at the centre of atoms to deflect them. He tested his assumptions by bouncing alpha particles off a sheet of gold leaf and determined that the most powerful part of an atom was a very small, heavy, core at its centre, a central electric charge concentrated at a point - the nucleus. This was surrounded by a cloud of electrons made up of an opposing electrical charge. This concept of opposite charges which, as David Eliot Brody and Arnold R Brody noted, "marks the beginning of the modern understanding of the structure of the atom", was Rutherford’s second great discovery. As Campbell says, "the nuclear model of the atom had been born".

 

This orbiting model was the most revolutionary idea of Rutherford’s career, as Nigel Costley, writing in the Sunday Star Times, relates: "Prior to Rutherford the best model of the atom was JJ Thomson's plum pudding which pictured it in a thin cloud of positive charges, with electrons dotted amongst it, like so many raisins in a plum pudding. Rutherford’s experiments showed the pudding idea was wrong, replacing it with a solar system model. An incredibly dense positively charged nucleus lay at the centre which was tiny compared to the whole atom; like a postage stamp in a football field. "Through his studies of radioactivity in the 1890s he discovered alpha particles which became, in his skilled and determined hands, the chief weapon in prising out the secrets of the sub-atomic world. These particles were known to be 7400 [closer to 7273] times heavier than electrons and when he fired them in huge numbers at a strip of very thin gold foil, it was expected they would effortlessly pass straight through. However a surprisingly high number were deflected [...]. Rutherford was astonished: "It was as if you fired a 15-inch shell at a sheet of tissue paper and it came back to hit you." From these deflections he was able to calculate the size of the nucleus."

 

During World War I Rutherford worked on acoustic methods of detecting submarines and developed several new technologies. He then drew on a lifetime’s strengths in practical experimentation for the third great breakthrough of his career.

 

Radioactivity had shown that some atoms spontaneously split, but in 1917 (reported 1919) the committed alchemist Rutherford, as McLauchlan writes, "detected the transmutation of one elementary material, nitrogen, into another, oxygen, which was induced artificially when the nitrogen atom was bombarded by the natural alpha articles of radium." Rutherford was, as he describes the process himself with typical understatement, "playing with marbles." He was using alpha particles to eject protons from materials containing hydrogen when he found the same thing happened in nitrogen (which doesn't contain hydrogen). But more importantly the proton came out at higher energy than it could have received by collision.

 

In that year Rutherford had written to Niels Bohr that, "... I am also trying to break up the atom by this method ... Regard this as private."

 

Effectively Rutherford had "broken up" or split the atom. With this experiment, he was the first human to create a "nuclear reaction", though a weak one. From Rutherford's first discovery onwards he had swept away accepted models of the stable atom, altered the course of modern science and made possible the development of nuclear physics. Once more Rutherford's demonstrations had changed the way we viewed and conceived of the world, breaking through the gross world of matter into the subtle world of atoms.

 

Return to Cambridge

 

Rutherford returned to Cambridge’s Cavendish Laboratory as Director, in 1919, and became well known for a personality to match his achievements, mentoring and directing others towards great discoveries. Prof. S. Devons in A Hundred Years and More of Cambridge Physics: Rutherford's Laboratory recounts: "Cambridge, and the Cavendish Laboratory especially, was an established, renowned centre of science. In the early 1930's its lustrous reputation was as high as ever. These years were indeed the "golden age" of the Cavendish ... His influence there seemed a wholly natural phenomenon. Benevolent guidance, leadership and intellectual authority flowed from him, and loyalty was returned. One would no more question his influence on those around him than one would that of the sun on the satellite planets. Rutherford, the Cavendish Professor, was the centre of light and warmth and life. It was the natural order of things."

 

Michael Kelly (one of the many New Zealanders who followed in Rutherford’s wake to study physics at Cambridge and now a world leader in the field of solid-state physics) has said that because of his tenacity, Rutherford was popularly known as "crocodile", because, as well as connoting the father of the family, a crocodile can never see its tail. It always looks forward and that’s how he was ... he would make bold imaginative leaps at what might be going on before setting up the experiments to check it. There are other people who work in much more formalistic ways, but he had an idea on the main chance."

 

Rutherford set high standards of research at Cambridge. Michael Kelly again: "Rutherford’s style of doing research set the tone for much of the experimental work done at Cambridge. His was very much a sealing wax and cotton style – ‘let’s have a go’."

 

A Genius For Astonishment

 

In Richard Rhodes’ book The Making of the Atomic Bomb, one of Rutherford’s protegees, James Chadwick, summed up his mentor as follows: "Rutherford’s ultimate distinction was ‘his genius to be astonished’." This key to Rutherford’s thought and approach reflects Rutherford’s background as much as his personality: growing up in the then rough and ready New Zealand backblocks, he was relatively free of the social constraints and acceptance of intellectual assumptions that marked the more genteel culture of British physicists. What Rhodes has called the "braiding of country-boy acuity with a profound frontier innocence" made Rutherford free of preconceptions and independent of accepted theories and assumptions, leading to his originality as a thinker and experimenter. A fellow student in his early days at Cambridge noted: "We've got a rabbit here from the Antipodes, and he's burrowing mighty deeply."

 

In his survey of Rutherford’s life, Nigel Costley reports that: "…you could tell when work was going well in Rutherford’s laboratory: he strode about singing a spirited rendition of "Onward Christian Soldiers." His character, full of hearty good humour interspersed with imperious commands, was more that of a boisterous colonial farmer than the world’s leading scholar. Yet by virtue of his forceful personality and an intuition for picking the right experiment, he was a revolutionary …. There was a paradox in this combination of an elderly conservative gentleman of the "old school" and the proponent, nay the discoverer, of the latest word in this most modern field of knowledge: atomic and subatomic physics…it was all part of the scene: Cambridge, the Cavendish and Rutherford alike; traditional forms and radical ideas; an enduring, time-beaten outer shell containing and protecting the vital, quickening activity within."

 

Simplicity was the key to Rutherford, says Devons: "There was an extraordinary transparent honesty and a deceptive simplicity about the clear distinction between fact and theory (opinion). He was impatiently hostile to any attempt to obscure or to conceal or to complicate unnecessarily…it was the remarkable combination of a most powerful imagination counterbalanced by a sense of utter honesty that was most impressive and mystifying. Rutherford's emphasis on simplicity is proverbial: ("I'm a simple man myself..."). Simple ideas and simple apparatus, but powerful, conclusive results; simple, unpretentious appearances, but striking inferences: these were the Cavendish trademarks."

 

Rutherford was a man of great energy and persistence, a keen golfer and motorist, and a mentor for young science students in Britain, especially New Zealanders.

 

The Great Mentor

 

James Chadwick, who won the Nobel Prize for Physics in 1935 for discovering the neutron (a particle first predicted to exist by Rutherford in 1920), was only one of a number of scientists who studied under Rutherford who achieved lasting fame. Another notable young colleague was Niels Bohr, who won his own Nobel Prize (for Physics in 1922) for placing the electrons in stable orbits around Rutherford's nucleus and thus explaining the origin of light emitted by hydrogen atoms. While at Manchester, Rutherford's assistant was Hans Geiger, and the 1907 Rutherford-Geiger detector was improved in 1928 to become the Geiger-Muller tube we know today for measuring radiation. Robert Oppenheimer, later to be known as the "father of the atomic bomb" for his leading role in developing the bomb in the Los Alamos Laboratory during the Second World War, also studied at Cavendish under Rutherford. As well, John Cockroft and Ernest Walton were driven by Rutherford to construct the first high energy accelerator and were the first to use it to split the nucleus using entirely artificial means.

 

The National Hero

 

Rutherford won a series of honours for his work, including the 1908 Nobel Prize for Chemistry, and 21 honorary degrees. He has been featured on the stamps of four countries: New Zealand, Sweden, Russia and Canada. He was named Baron Rutherford of Nelson in 1931 at the age of 59, choosing as his coat of arms a design that included a kiwi and a Maori warrior. He remained proud of his New Zealand origins and his family: on being awarded his baronetcy, he sent a telegram to his mother: "Now Lord Rutherford. More your honour than mine. Ernest." 

 

However the baronetcy was awarded at a sad time in his life: 8 days before the award the Rutherford’s only daughter Eileen had died, nine days after the birth of her fourth child.

 

On the visits Rutherford made back home to New Zealand he was a celebrated figure. In 1925 he came home for the last time, for six weeks, to see family and give lectures. In Auckland he stated, "I have always been very proud of the fact that I am a New Zealander." Described by reporters of the day as "an imposing figure, tall, well-built and with bright blue eyes", Campbell chronicles how Rutherford was hailed as a national hero, lectured to packed halls and called for the Government to protect New Zealand’s natural heritage. He also called for an institute to be set up in which New Zealand scientists could carry out research that would benefit farmers: this assisted in the establishment of the Department of Scientific and Industrial Research in 1926.

 

He was still a seemingly healthy vigorous man, when he entered hospital for a minor hernia operation after straining himself by cutting down some trees on his property. Within a few hours of the operation on 15th October it was clear his intestines were not working. His intestines never worked again. Four days later, he suddenly said to his wife from his sickbed, "I want you to leave one hundred pounds to Nelson College. You can see to it." Then he added more loudly, "Remember, a hundred to Nelson College." He hardly spoke after that according to his wife, and at the early age of sixty-six Rutherford died, late on 19 Oct, 1937. His ashes were interred at Westminster Abbey near the tombs of Isaac Newton and Lord Kelvin. His medals were gifted to Canterbury College, now University of Canterbury. In 1992 his image was placed on the new New Zealand $100 note.

 

 

 

 

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