Ernest Rutherford

The New Zealand physicist Ernest Rutherford, who lived from August 30, 1871, to October 19, 1937, was a trailblazer in the fields of nuclear and atomic physics. "The Father of Nuclear Physics" and "The greatest experimentalist since Michael Faraday" are two titles that have been applied to Rutherford. He was given the Nobel Prize in Chemistry in 1908 "for his investigations into the chemistry of radioactive substances and the disintegration of the elements." Along with being the first to do the winning work in Canada, he was the first Oceanian Nobel laureate.

Some of the discoveries made by Rutherford include the name and distinction between alpha and beta radiation, the notion of radioactive half-life, and the radioactive element radon. Rutherford and Thomas Royds are credited with establishing the helium nuclei's composition of alpha radiation. He postulated in 1911 that the charge of an atom is concentrated in its tiny nucleus. This was accomplished by his identification and explanation of Rutherford scattering following Hans Geiger and Ernest Marsden's gold foil experiment, which led to the development of the Rutherford model of the atom. He conducted experiments in 1917 in which he attacked nitrogen nuclei with alpha particles, resulting in the first artificially induced nuclear reaction. Consequently, he detected the presence of a subatomic particle that he originally referred to as the "hydrogen atom" but now (more precisely) dubbed the proton. Alongside Henry Moseley, he is also known for having developed the atomic numbering system. Among his other accomplishments are the advancements in ultrasound technology and radio communications.

In 1919, Rutherford was appointed Director of the University of Cambridge's Cavendish Laboratory. James Chadwick made the neutron discovery in 1932 under his direction. Under his supervision, John Cockcroft and Ernest Walton carried out the first controlled experiment to divide the nucleus that same year. In recognition of his contributions to science, Rutherford was made a Baron by the peerages of Britain and New Zealand. He was interred in Westminster Abbey next to Charles Darwin & and Isaac Newton upon his death in 1937. In 1997, rutherfordium (104Rf), a chemical element, was named in his honor.

Childhood and schooling

In Brightwater, a town close to Nelson, New Zealand, on August 30, 1871, Ernest Rutherford was born. James Rutherford, an immigrant farmer and mechanic from Perth, Scotland, and his wife Martha Thompson, a schoolteacher from Hornchurch, England, had twelve children total, of whom he was the fourth. On Rutherford's birth certificate, "Earnest" was typed in error. His family referred to him as Ern. Rutherford relocated to Foxhill when he was five years old, where he attended Foxhill School. The Rutherford family relocated to Havelock, a town in the Marlborough Sounds after his father moved there when he was eleven years old in 1883. The purpose of the relocation was to be nearer the father's flax mill, which was located close to the Ruapaka Stream. Ernest was a Havelock School student.

Upon retrying in 1887, he was awarded a scholarship to attend Nelson College. He scored 452 out of 600 on his first exam try, including 75 out of 130 for geography, 76 out of 130 for history, 101 out of 140 for English, 200 out of 200 for arithmetic. He received the best grades of everyone from Nelson with these scores. At the time of his scholarship award, he had scored 580 out of 600. Havelock School gave him a five-volume bundle of books entitled The Peoples of the World after he was awarded the scholarship. From 1887 to 1889, he attended Nelson College, where in 1889, he held the position of head boy. He participated in rugby at the school as well. Despite having 15 months left of college, he turned down an offer of a government cadetship. After attempting again in 1889, he was awarded a scholarship by the University of New Zealand to attend Canterbury College between 1890 and 1894. He was involved in the Science Society and its debate society. He received his complicated BA in Latin, English, and mathematics from Canterbury in 1892; his MA in mathematics and physical science from the same institution in 1893; and his BSc in geology and chemistry from Canterbury in 1894.

After that, he created a novel kind of radio receiver. In 1895, the Royal Commission for the Exhibition of 1851 granted Rutherford an 1851 Research Fellowship, which allowed him to visit Cambridge University's Cavendish Laboratory in England to pursue graduate studies there. He received the Coutts-Trotter Studentship and a BA Research Degree from Trinity College, Cambridge, in 1897.

Education

Cambridge University

In light of the growing significance of science, the University of Cambridge has modified its regulations to permit graduates from other universities to obtain a Cambridge degree following two years of study and the successful completion of a recognized research project. Rutherford was the first student at the institution to do research. In addition to demonstrating that an oscillatory discharge will magnetize iron, which was previously known, Rutherford also discovered that an alternating current-generated magnetic field caused a magnetized needle to lose some of its magnetization. As a result, the needle became an electromagnetic wave detector-a phenomenon that was just recently identified. Such waves were predicted to exist in 1864 by the Scottish physicist James Clerk Maxwell, and they were discovered in laboratory tests by the German scientist Heinrich Hertz between 1885 and 1889. Rutherford invented a simpler, potentially practical device to detect electromagnetic waves, also known as radio waves. He worked at Cavendish Laboratory for a year after that, extending the device's sensitivity and range to half a mile. But Rutherford lacked the transcontinental vision and business acumen of Guglielmo Marconi, the Italian scientist who created the wireless telegraph in 1896.

Just a few months after Rutherford arrived at the Cavendish, physicist Wilhelm Conrad Röntgen made the discovery of X-rays in Germany. X-rays fascinated scientists and laypeople alike because they could capture silhouette photos of bone structure in a living hand. Scientists were especially interested in finding out what they were and their qualities. Rutherford was unable to turn down Thomson's kind invitation to work with him on a study looking into how X-rays affected a gas's conductivity. A landmark work on ionization-the splitting of atoms or molecules into both positive and negative components, or ions-and the attraction of charged particles to electrodes with opposite polarity was the result of this.

Rutherford investigated various radiations that created ions, while Thomson investigated the charge-to-mass ratio of the most frequent ion, which was subsequently named the electron. Rutherford studied radiation from ultraviolet light first and, subsequently, radiation from uranium. (1896 saw the discovery of uranium radiation by French physicist Henri Becquerel.) Rutherford was shown by placing uranium close to thin foils that the radiation was more complicated than previously believed. While one type of radiation was readily absorbed or blocked by a very thin foil, another type frequently penetrated the same thin foil. For the sake of convenience, he called these radiation types beta and alpha, respectively. (It was subsequently discovered that the beta particle is equivalent to an electron or its positive form, a positron, and the alpha particle is equivalent to the nucleus of an ordinary helium atom, which is composed of two protons and two neutrons.) These radiations became the main focus of research for a few years after that, with radioactive elements-also known as radioelements-earning the majority of scientific attention as they began to release radiation.

University of McGill

Because of his research prowess, Rutherford was appointed to a position at McGill University in Montreal, home of one of the top laboratories in the Western Hemisphere. He and a colleague discovered that thorium released a gaseous radioactive product that he named "emanation" after shifting their focus to another of the few elements that were known to be radioactive at the time. Consequently, a strong active deposit was left behind, which quickly separated into thorium A, B, C, and so on. It's interesting to note that some radioelements lost radioactivity after chemical treatment but eventually recovered it back, whereas other materials, which were initially strong, gradually lost activity. This gave rise to the notion of half-life, which is, to put it in modern terminology, the amount of time needed for half of the atomic nuclei in a radioactive sample to decay. Half-lives can vary from seconds to billions of years and are specific to each radioelement, making them a great means of identification.

Rutherford realised that the increasing number of radioelements meant he needed professional chemical assistance. In that order, he drew in the expertise of German postdoctoral researcher Otto Hahn, Yale University professor Bertram Borden Boltwood, and McGill demonstrator Frederick Soddy. Rutherford's greatest achievement at McGill was co-developing the transformation theory, sometimes known as the disintegration hypothesis, with Soddy in 1902-1903. Atoms were considered stable bodies, and alchemy and its theories of turning elements like lead into gold had long since been banished from what was called modern chemistry. However, Rutherford and Soddy now asserted that the atom itself contained the energy responsible for radioactivity and that the spontaneous release of an alpha or beta particle indicated a chemical transition from one element to another. They anticipated controversy around this iconoclastic hypothesis, but their overwhelming experimental data silenced critics.

It was soon discovered that the radioelements belonged to three families, or decay series, with actinium, uranium, and thorium at the head and inactive lead at the end. As per Rutherford's recommendation, Boltwood positioned radium in the uranium series and demonstrated that the age of ancient rocks was within the billion-year range by utilizing the gradually increasing lead content in a mineral. Because the alpha particle possessed a palpable mass, Rutherford believed it to be essential to transformations. He found that it was positively charged, but he was unable to identify if the ion was hydrogen or helium. Rutherford married his New Zealand sweetheart while attending McGill and rose to fame. At a period when few women pursued science degrees, he welcomed an increasing number of female research students to his lab. In addition to writing magazine articles and giving popular speeches, he was also the author of radiation (1904), the best-selling textbook of the time on radiation. He received medals and a fellowship in the Royal Society of London. Soon after, job offers followed.

Manchester University

Although there was a strong scientific community in North America, Europe was the core of physics worldwide. Rutherford took up the offer of a post at the University of Manchester in 1907, whose physics laboratory was the best in England, surpassed only by Thomson's Cavendish Laboratory. A year later, he was awarded the Nobel Prize in Chemistry in recognition of his work in Montreal.

Along with German physicist Hans Geiger, Rutherford created an electrical counter for ionized particles. Geiger refined the device, which led to the creation of the Geiger counter-an instrument used worldwide for radioactivity measurement. The glassblower in the lab was quite skilled. With his help, Rutherford and his pupil Thomas Royds were able to separate out some alpha particles and use spectrochemical analysis to determine that they were helium ions. Following his visit to Rutherford's lab, Boltwood and the scientist collaborated to recalculate the rate at which helium is produced from radium, allowing them to compute Avogadro's number precisely. Sir J.J. Thomson's theory that the atom is a uniformly dispersed substance was refuted by Rutherford in 1909. Rutherford realized that the bulk of the gold atom must be concentrated in a small dense nucleus because most of the alpha particles in his beam passed through the foil entirely, and only a small percentage were scattered by huge angles.

Rutherford investigated the alpha particle's modest scattering when it collided with a foil, maintaining his long-standing interest in the particle. When Geiger joined him, the amount of quantitative data they collected increased. Rutherford recommended that an undergraduate student named Ernest Marsden hunt for large-angle scattering in 1909 when he required a research assignment. Rutherford later remarked, "It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper, and it came back and hit you," with some embellishment after Marsden discovered that a small percentage of alphas had been twisted more than 90 degrees from their initial path. Scientist Ernest Rutherford thought of the atom as a tiny solar system comprising electrons circling a hefty nucleus and the nucleus taking up a very small portion of the atom. Rutherford proposed his concept, which had a nucleus made up only of protons before the neutron was found.

Since electrostatic attraction or repulsion could turn a heavy, charged particle like alpha through such a large angle, Rutherford (1911) reasoned that an atom could not be a homogeneous solid but rather mostly consist of empty space with its mass centered in a tiny nucleus. The biggest scientific contribution of Rutherford was this revelation (the Rutherford atomic model) and the experimental evidence that backed it up, yet it was not widely acknowledged outside of Manchester. But Niels Bohr, the Danish scientist, demonstrated its significance in 1913. After visiting Rutherford's lab the previous year, Bohr returned as a faculty member from 1914 to 1916. He clarified that while orbital electrons cause chemical qualities radioactivity is attributed to the nucleus. By incorporating the novel idea of quanta, or particular discrete energy values, into the electrodynamics of orbits, his theory-the Bohr atomic model-explained spectral lines as the result of electrons absorbing or releasing energy as they transition between orbits. Another of Rutherford's several students, Henry Moseley, offered a similar explanation for the elements' X-ray spectrum sequence, citing the electron charge on the nucleus. As a result, a cogent new understanding of nuclear physics and atomic physics was created. Rutherford's laboratory was practically empty during World War I, and he was actively engaged in antisubmarine research. In addition, he served on the Board of Invention Research of the Admiralty. Rutherford studied the collision between alpha particles and gases when he had time to go back to his previous areas of interest. Nuclei, or individual protons, were driven to the detector in the case of hydrogen, as was predicted. Unexpectedly, though, protons also emerged when alphas collided with nitrogen. A nuclear reaction in a stable material was artificially induced, as Rutherford revealed in 1919, explaining his third major finding.

Career

One of the first "aliens" (those without a Cambridge degree) to be permitted to do research at the university when Rutherford started his studies there, he also had the honour of studying under J. J. Thomson. At 800 meters, Rutherford discovered radio waves with Thomson's encouragement. For a short while, he held the record for the furthest electromagnetic wave detection range. However, when he presented his findings at the British Association meeting in 1896, he found that Guglielmo Marconi had surpassed him with radio waves that had traveled nearly 16 kilometers.

Return of Ernest Rutherford to Cambridge

Rutherford spent the rest of his career dealing with such nuclear reactions, returning to the University of Cambridge to take over as head of the Cavendish Laboratory after Thomson's death in 1919. Manchester-based physicist James Chadwick was one of Rutherford's colleagues whom he recruited to Cavendish. When combined, they produced metamorphoses by exposing several light elements to alpha radiation. However, because one another's charges repulsed the alphas, they were unable to enter the nuclei of the more powerful substances. Moreover, scientists were unable to ascertain whether the alpha rebounded off or fused with the target nucleus following impact. More sophisticated technology was required in both situations.

For the former, by the late 1920s, the greater energy generated in particle accelerators was accessible. The first nuclear transition was really generated by two of Rutherford's students, John D. Cockcroft of England & Ernest T.S. Walton of Ireland, in 1932. Using a high-voltage linear accelerator, they attacked lithium with protons, splitting it into two alpha particles. (For this achievement, the two shared the 1951 Nobel Prize in Physics.) Regarding what actually happened in a collision, Scottish physicist Charles T.R. Wilson invented the cloud chamber in the Cavendish lab. This allowed scientists to see the tracks left by charged particles and earned him the 1927 Nobel Prize in Physics. A little over 400,000 alpha collisions were photographed in 1924 thanks to modifications made to the cloud chamber apparatus by the English physicist Patrick M.S. Blackett. Of these, eight demonstrated disintegrations, in which the alpha particles were absorbed into the target nucleus before the nucleus ruptured into two fragments. For this and other significant contributions to our understanding of nuclear processes, he was given the 1948 Nobel Prize in Physics.

Rutherford Model

Ernest Rutherford, a physicist who was born in New Zealand, proposed the Rutherford model (1911) as a description of the atomic structure. According to the idea, each atom consists of a small, compact, positively charged core known as the nucleus, around which almost all of the mass is concentrated. The electrons, or light, negative elements, orbit the nucleus at a certain distance, resembling planets orbiting the Sun. Sir J.J. Thomson's theory that the atom is a uniformly dispersed substance was refuted by Rutherford in 1909. Rutherford realised that the bulk of the gold atom must be concentrated in a small dense nucleus because most of the alpha particles in his beam passed through the foil entirely and only a small percentage were scattered by huge angles.

In 1909, Ernest Marsden, an undergraduate student working with Rutherford and German physicist Hans Geiger, conducted a series of experiments that led to the hypothesis that the nucleus was compact and dense in order to explain the scattering of alpha particles through thin gold foil. A lead shield protected a radioactive source that released alpha particles, which are positively charged particles that are 7,000 times larger than electrons and identical to the nucleus of a helium atom. The radiation went through a slit in a lead screen and was focussed into a narrow beam. A slit was covered with a thin layer of gold foil, and a screen that had been fluorescently coated with zinc sulphide was used as a counter to identify alpha particles. A scintillation, or flash of light produced when an alpha particle struck a fluorescent screen, was visible through a viewing microscope that was fixed to the back of the screen. Since the screen was moveable, Rutherford and his colleagues could check to see if the gold foil was deflecting any alpha particles.

According to the gold foil, the majority of alpha particles flowed through it directly, suggesting that open space makes up the majority of each atom. A small amount of alpha particle deflection was observed, indicating possible interactions with additional positively charged atom-wide particles. A very small number of alpha particles even rebounded back towards the source, while the rest were distributed at wide angles. "It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper, and it came back and hit you," Rutherford remarked famously after that. Such tremendous repulsion could only be explained by a positively charged and somewhat hefty target particle, like the suggested nucleus. It was believed that the negative electrons orbiting the nucleus in circular paths were responsible for electrically balancing the positive nuclear charge. The gravitational force of attraction between the Sun and the rotating planets was compared to the electrostatic force of attraction between electrons the nucleus. There was no obstruction to the alpha particles' passage throughout the majority of this planetary atom.

The English physicist Sir J.J. Thomson's "plum-pudding" atomic model, which proposed that electrons were lodged in a positively charged atom like plums in a pudding, was superseded by the Rutherford model. In a few years, the Bohr atomic model-which included some early quantum theory-superseded the Rutherford model, which was entirely based on classical physics.

Physics behind nuclear energy

The reason Rutherford is referred to as "the father of nuclear physics" is that his work as laboratory director and his individual research led to the establishment of the nuclear structure of the atom and the fundamental characteristics of radioactive decay as a nuclear process. Using naturally occurring alpha particles, Patrick Blackett, a research fellow under Rutherford, showed induced nuclear transmutation. Rutherford's group later showed artificially induced nuclear reactions & transmutation using protons from an accelerator.

Rutherford passed away too soon to witness the development of Leó Szilárd's theory of controlled nuclear chain reactions. Szilárd said, however, that Rutherford's statement regarding his experimentally induced transmutation in lithium-which appeared in the September 12, 1933, issue of The Times-was the source of his inspiration when considering the potential for a nuclear chain reaction that could produce regulated energy. During his address, Rutherford mentioned the work done in 1932 by his students John Cockcroft & Ernest Walton, who used a particle accelerator they had built to bombard lithium with protons, "splitting" it into alpha particles. Although Rutherford recognized that the energy released from the split lithium atoms was enormous, he also realized that the project was not feasible as a practical source of energy due to the energy required for the accelerator and its inherent inefficiency in splitting atoms in this manner (even today, accelerator-induced fission of light elements remains too inefficient to be used in this manner).