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  Born 130 years ago in rural New Zealand, Ernest Rutherford unraveled the mysteries of radioactivity, determined the structure of the atom, split the atom, and led research labs on two continents.
"It is given to but few men to achieve immortality, still less to achieve Olympian rank, during their own lifetime. Lord Rutherford achieved both. In a generation that witnessed one of the greatest revolutions in the entire history of science he was universally acknowledged as the leading explorer of the vast, infinitely complex universe within the atom, a universe that he was first to penetrate. " ----Eulogy in the New York Times, 1937  rnest Rutherford is to the atom what Darwin is to evolution, Newton to mechanics, Faraday to electricity, and Einstein to relativity. Rutherford's fame is based not on one discovery but rather on three separate occasions in which he radically altered our understanding of nature. These were three giant steps toward today's generally accepted understanding of the elemental building blocks of matter, atoms.
Through brilliantly conceived experiments, and with special insight, he explained the perplexing problem of radioactivity as the spontaneous disintegration of atoms. He also determined the nuclear structure of the atom, and, as the world's first successful alchemist, converted nitrogen into oxygen. Or put another way, he was first to split the atom. Any of his secondary discoveries, such as dating the age of the earth, would have given fame to a lesser scientist. For example, the first method invented to detect individual nuclear particles by electrical means, the Rutherford-Geiger detector, evolved into the Geiger-Muller tube. The modern smoke detector, responsible for saving so many lives in house fires, can be traced back to 1899 when, at McGill University in Canada, Rutherford blew tobacco smoke into his ionization chamber and observed the change in ionization. A country boy  is background is unique, in that he was born in New Zealand. A mere 50 years after formal European settlement, that remote British colony admitted him to its university, already 20 years old.
Ernest Rutherford was born at Spring Grove in rural Nelson on August 30, 1871, the second son and fourth child of 12 born to James and Martha Rutherford. Scottish James, who had arrived in New Zealand in 1843 as a four-year-old, became a wheelwright and engineer. As a boy Ernest was surrounded by hardworking people with technical skills. Martha Rutherford (formerly Thompson) was born in England and arrived in New Zealand in 1855 when she was 13. She worked as a teacher before she married. So Ernest and his siblings received a good education because of parents who appreciated education: James because he hadn't had much and Martha because she had. Ernest led the life typical of a child growing up in rural New Zealand. Family chores, such as milking cows and gathering firewood, ate up time after school. On Saturdays the boys were free for swimming in the creek and bird's-nesting (collecting and selling eggs from bird nests) to raise money for slingshot rubber and kite strings. At age 10 Ernest received his first science book. Among the many suggested experiments in it, one, on using the speed of sound to determine the distance to a firing cannon, gave him the knowledge to surprise his family by estimating the distance to a lightning flash. Perhaps it was also this book that inspired him to make a miniature cannon out of a hat peg, a marble, and blasting powder. The cannon exploded, without causing injury. Ernest was lucky to avoid the drowning fate of two of his brothers and lucky to be taught by a country schoolteacher of above-average ability. In 1887, 16-year-old Ernest, on his second attempt, won the only scholarship available to assist a boy from his area to attend the regional secondary school, Nelson College. For the next three years he boarded at Nelson College. In 1889 he was head boy, played on the rugby team, and, once again on his second attempt, won one of the 10 scholarships available nationally to assist attendance at a college of the University of New Zealand. University days  rom 1890 to 1894 Rutherford attended Canterbury College in Christchurch. There he played rugby and participated in the activities of the Dialectic Society (a student debating society), the graduation day celebrations (for which he cowrote one song), and the recently formed Science Society. In 1892 he passed his bachelor of arts in pure mathematics and Latin (both compulsory), applied mathematics, English, French, and physics.
His mathematical ability won him the one senior scholarship in mathematics available in New Zealand. This allowed him to return for a further (honors or master's) year, during which he took both mathematics and physics. The physics course required an original investigation, so Rutherford elected to extend an undergraduate experiment to determine if iron was magnetic at very high frequencies of magnetizing current. Through this work, he developed two devices: a magnetic detector of very fast current pulses; and a simple mechanism for switching two electrical circuits, with a time interval between them that could be adjusted to be as short as two hundred thousandths of a second. In 1893 Rutherford obtained a master of arts degree with double first-class honors, in mathematics and mathematical physics and in physical science (electricity and magnetism). Having failed for the third time to obtain a permanent job as a schoolteacher, and having briefly considered going into medicine, Rutherford had few other career options. He seemed to be limited to tutoring, to help support himself while carrying out a bit more research in electrical science. Meanwhile, far away in England, the educational trust of the Royal Commission for the Exhibition of 1851 had initiated scholarships to allow graduates of universities in the British Empire to go anywhere in the world and work on research of importance to their home country's industries. Every second year, one scholarship was available for a new graduate of the University of New Zealand. (A candidate for a scholarship had to be enrolled at the university.) Thus it was that in 1894 Rutherford returned to Canterbury College, where he took geology and chemistry for a bachelor of science degree. For the research work required of a candidate, he extended his researches of the previous year to even higher frequencies using the damped oscillatory current from a Leyden jar (an electrical capacitor) or a Hertzian oscillator. He showed that a steel needle surrounded by a wire loop in the discharge circuit was indeed magnetized for frequencies as high as 500 million cycles per second. Further, by slowly dissolving the needle in acid he showed that only a very thin surface layer of the needle was magnetized. Approaching the new physics  y good fortune, the university's first choice for nomination to the Exhibition of 1851 scholarship was unable to accept it. The university therefore nominated Rutherford, the only other candidate, who was duly awarded it.
Ernest Rutherford left New Zealand in 1895 as a highly skilled 23-year-old. He held three degrees from the University of New Zealand and had a reputation as an outstanding researcher and innovator working at the forefront of electrical technology. His brilliance at experimental research was already established. He elected to work with Professor J.J. Thomson of Cambridge University's Cavendish Laboratory. Rutherford adapted his detector of very fast transient currents
Encouraged by Sir Robert Ball, who wished to find a way for ships to detect a lighthouse in the fog, Rutherford increased the sensitivity of his apparatus. In February 1896 he could detect electromagnetic waves over a distance of several hundred meters, then a world record. At this moment, as Rutherford was on the verge of establishing the foundations of wireless signaling, Thomson, who was about to discover the first object smaller than an atom (the electron), invited him to join in a study of the electrical conduction of gases. Wireless telegraphy was thus left for Guglielmo Marconi to develop and commercialize. Working with Thomson, Rutherford developed several ingenious techniques for studying the mechanism whereby applying a high voltage across normally insulating gases causes them to become electrical conductors. When X rays were discovered a few months later, he used them to initiate electrical conduction in gases. He repeated this with rays from radioactive atoms when they were discovered in 1896. Rutherford's interest soon switched to understanding radioactivity itself, an interest that became his life's work, but his contribution to the earlier fields should not be forgotten. Unraveling radioactivity  n 1898 Rutherford discovered that two quite separate types of emissions came from radioactive atoms; he named them alpha and beta rays. Beta rays were soon shown to be high-speed electrons.
Barred in the near term from advancement at Cambridge, Rutherford accepted a professorship at McGill University in Montreal in 1898. (The following year Cambridge University changed its rules to allow earlier promotion to fellowship.) The laboratories at McGill were very well equipped. As Rutherford wrote to his wife to be, "I am expected to do a lot of work
At McGill, Rutherford promptly discovered radon, a chemically unreactive but radioactive gas. In this he was assisted by his first research student, Harriet Brookes. With the later help of a young chemist, Frederick Soddy, Rutherford unraveled the mysteries of radioactivity, showing that some heavy atoms spontaneously decay into slightly lighter atoms. This was the work that first brought him to world attention. He was elected a fellow of the Royal Society of Canada in 1900 and of London in 1903. His first book, Radioactivity, was published in 1904. In 1908 he was awarded the Nobel Prize in chemistry for his investigations into
On realizing that lead was the final decay product of uranium, Rutherford proposed that if the decay rate of uranium were known, and the relative proportions of lead and uranium in a sample were measured, it should be possible to date minerals. Subsequently, this technique was used for placing a lower limit on the age of the formation of the planet. Radioactive dating of geological samples underpins modern geology. While in Canada, Rutherford was regularly head-hunted by American universities and institutions, for example Yale and the Smithsonian Institute. The main result of these approaches was that McGill kept upping his salary. Rutherford always had a shift in mind but only to Britain, to be nearer the main centers of science and to have access to more, and better, research students. The atom unveiled  hus when he was offered a chair at Manchester University back in England, Rutherford readily accepted it. Transferring there in 1907 he showed convincingly what he had long suspected, namely that the alpha particle was a helium atom stripped of its electrons. He and an assistant, Hans Geiger, developed the sustainable electrical method of repetitively and rapidly detecting single particles emitted by radioactive atoms, the Rutherford-Geiger detector. With this he could determine such important physical constants as Avogadro's number, the number of atoms or molecules in one gram-mole of material.
At McGill, Rutherford had noted that a narrow beam of alpha particles
In 1911, Rutherford deduced from these results that almost all the mass of an atom--an object so small that it would take over five million of them side by side to cross a period on this page--is concentrated in a nucleus a thousand times smaller than the atom itself. (If the orbital electrons in all the atoms in a human body were compressed into the nucleus, we would occupy the space of a grain of sand.) The nuclear model of the atom had been born.
Rutherford's only patent is from his development of a directional hydrophone used for locating submarines. That patent was assigned to the British Admiralty, for whom he worked during World War I. When the Americans finally entered the war in 1917, Sir Ernest Rutherford (he had been knighted in 1914) led the delegation to transfer submarine-detection knowledge to them. He fruitlessly advised the American government to use young scientists on problems associated with war work rather than waste their lives and skills in the trenches. (One of Rutherford's brightest students, Harry Moseley, on track for a Nobel Prize for his work on using X rays to probe the electronic structure of atoms, had been killed in Turkey.) Near the end of the war Rutherford returned to the pursuit of nonwar science. While bombarding light atoms with alpha rays, he observed outgoing protons whose energy was larger than that of the incoming alpha particles. From this observation he correctly deduced that the bombardment had converted nitrogen atoms into oxygen atoms. He thus became the world's first successful alchemist and the first person to split the atom, his third great claim to fame. Return to Cambridge n 1919 Rutherford became the director of Cambridge University's Cavendish Laboratory, leading it through a decade of consolidation, setting up a first-class research team, and tidying up loose ends. In 1925 he traveled to Australia and New Zealand to give public lectures and visit his ailing parents. Rutherford was then an imposing figure: tall, well-built, and with bright blue eyes. The six-week tour of New Zealand, his fourth and last visit to his homeland,
Rutherford was elevated to the peerage in the New Year's honors list for 1931, thus becoming Ernest, Lord Rutherford of Nelson. He chose to include in his coat of arms a kiwi, a Maori warrior, and Hermes Trismegistus, the patron saint of knowledge and alchemists. His shield is quartered by the curves of the decay and growth of radioactivity. His Latin motto, Primordia Quaerere Rerum (which translates as "To Seek the Nature of Things"), was chosen from Lucretius' On the Nature of the Universe. He spoke only twice in the House of Lords, on both occasions in support of industrial research. Guided by Rutherford, the Cavendish Laboratory became one of the preeminent sites in the world where the onrushing theoretical developments of physics were tied to experimental discoveries. The lab's contributions in 1932 are of particular note. In that year, James Chadwick discovered the neutron, whose existence Rutherford had predicted a decade earlier. In the interim Rutherford had often mentioned to Chadwick what properties this new particle must have. Also in 1932, Cavendish researchers John Cockcroft and Ernest Walton finally split the atom by bombarding the element lithium with protons, the nuclei of hydrogen atoms, which had been accelerated to very high speeds in a high-voltage accelerator they had created. This was the first nuclear fission induced by entirely artificial means. (Rutherford's earlier fission was not entirely artificial, as he used naturally accelerated alpha particles from a radioactive source.) For years Rutherford had assumed that to penetrate the nucleus of an atom one would need particles accelerated through a few million volts to match the energy with which particles were ejected from radioactive atoms. Hence he had cajoled British industry to push development of high-voltage sources. The breakthrough though came from George Gamow's application of quantum mechanics to show that lower energies would be more efficient at penetrating the atomic nucleus. After Cockcroft and Walton's success and following Gamow's theoretical lead, Rutherford had Mark Oliphant build a lower-voltage accelerator with a particle beam that was much higher in density. They used their new accelerator to bombard heavy hydrogen (deuterium, H2) with itself, discovering thereby not only tritium (H3, the third isotope of hydrogen) but the light isotope of helium (He3). Senior statesman of science  utherford served his science, laboratory, university, and adopted country well. He campaigned for Cambridge University to grant women the same privileges as men. He carried out regular public duties such as supporting the freedom of the British Broadcasting Corporation from government censorship, served on its panel of advisers, and gave regular radio talks on his work. When Hitler rose to power in Germany in 1933 and commenced his non-Aryan policy, Lord Rutherford helped found, and was president of, the Academic Assistance Council, which aided displaced academics. This was to be one of the biggest mass migrations of scientists the world had seen, and it began the transference of the center of science from Europe to America. These aspects of his life's work are almost forgotten but deserve greater recognition. Most Sundays he played golf for recreation.
Ernest Rutherford died at age 66 on October 19, 1937, because of delays in operating on his partially stangulated umbilical hernia. His ashes were interred in London's Westminster Abbey, near the remains of Isaac Newton and other notable British scientists. Lady Rutherford retired to Christchurch, New Zealand, where she died in 1954. Rutherford's medals, possibly the best assemblage of scientific medals in the world, were given to the University of Canterbury. During his lifetime Rutherford was awarded scientific prizes and honorary degrees from many countries and fellowships of many societies and organizations (such as the Royal College of Physicians and the Institution of Electrical Engineers). Among other honors he was elected president of the Royal Society (1926--1930) and president of the Institute of Physics (1931--33). He was decorated with the Order of Merit in 1925. Death did not stop the public acclamation. Buildings have been named in his honor in many countries, and he has appeared on the stamps of four nations. Rutherford's discoveries are his real memorial. What many have forgotten is his humility in giving his coworkers more than full credit. While he was at Manchester he chose not to put his name on a third of the papers reporting on radioactivity, though he had initiated almost every investigation. Often he would do the preliminary work, then hand the topic to a student or colleague. His humility should also be a memorial. 
Additional Reading John Campbell, Rutherford: Scientist Supreme, AAS Publications, Christchurch, New Zealand, 1999. ------, Rutherford's Ancestors, AAS Publications, Christchurch, New Zealand, 1996. (Inquiries to aas@its.canterbury.ac.nz):On the Web Additional Reading:"Uranium Radiation and the Electrical Conduction Produced by It"--a scientific paper by Ernest Rutherford http://dbhs.wvusd.k12.ca.us/Chem-History/Rutherford-Alpha&Beta.html Ernest Rutherford--Nobel biography with hypertext links http://www.obel.se/chemistry/laureates/1908/rutherford-bio.html Rutherford Organization (forthcoming) http://www.rutherford.org.nz John Campbell is the convenor of the Rutherford Birthplace Project. He teaches physics at the University of Canterbury in New Zealand. He can be reached at j.campbell@phys.canterbury.ac.nz |
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