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vol IV chap 13 sect 2

Volume IV: Universe

Previous: 13.1. Descriptions of laboratory instruments.


13.2. Accounts of experimental results.

The description of the Nobel Prize contributions is the same as in Section 13.1.

The experimental results.

(Source: Wikipedia commons)

Figure 13.3. Original plate obtained by Becquerel and table showing the main differences between natural and artificial radioactivity.

Ph1903 to Antoine Henri Becquerel “in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity” and to Pierre Curie and Marie Curie, née Sklodowska “in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel”.

WORK (Becquerel): “When Henri Becquerel investigated the newly discovered X-rays in 1896, it led to studies of how uranium salts are affected by light. By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate. Further studies made it clear that this radiation was something new and not X-ray radiation: he had discovered a new phenomenon, radioactivity.”

MLA style: Henri Becquerel – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Sun. 6 Oct 2024. https://www.nobelprize.org/prizes/physics/1903/becquerel/facts/

NOBEL LECTURE: On Radioactivity, a New Property of Matter by Becquerel.

MLA style: Henri Becquerel – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1903/becquerel/lecture/

WORK (Pierre Curie): “The 1896 discovery of radioactivity by Henri Becquerel inspired Marie and Pierre Curie to further investigate this phenomenon. They examined many substances and minerals for signs of radioactivity. They found that the mineral pitchblende was more radioactive than uranium and concluded that it must contain other radioactive substances. From it they managed to extract two previously unknown elements, polonium and radium, both more radioactive than uranium.”

MLA style: Pierre Curie – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Sun. 6 Oct 2024. https://www.nobelprize.org/prizes/physics/1903/pierre-curie/facts/

NOBEL LECTURE: Radioactive Substances, Especially Radium by Pierre Curie.

MLA style: Pierre Curie – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1903/pierre-curie/lecture/

WORK (Marie Curie): “The 1896 discovery of radioactivity by Henri Becquerel inspired Marie Skłodowska Curie and Pierre Curie to further investigate this phenomenon. They examined many substances and minerals for signs of radioactivity. They found that the mineral pitchblende was more radioactive than uranium and concluded that it must contain other radioactive substances. From it they managed to extract two previously unknown elements, polonium and radium, both more radioactive than uranium.”

MLA style: Marie Curie – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Sun. 6 Oct 2024. https://www.nobelprize.org/prizes/physics/1903/marie-curie/facts/

No Lecture was delivered by Mme. Curie

Ch1908 to Ernest Rutherford “for his investigations into the disintegration of the elements, and the chemistry of radioactive substances”.

WORK: “The discovery of radioactivity in 1896 led to a series of more in-depth investigations. In 1899 Ernest Rutherford demonstrated that there were at least two distinct types of radiation: alpha radiation and beta radiation. He discovered that radioactive preparations gave rise to the formation of gases. Working with Frederick Soddy, Rutherford advanced the hypothesis that helium gas could be formed from radioactive substances. In 1902 they formulated a revolutionary theory: that elements could disintegrate and be transformed into other elements.”

MLA style: Ernest Rutherford – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1908/rutherford/facts/

NOBEL LECTURE: The Chemical Nature of the Alpha Particles from Radioactive Substances by Rutherford.

MLA style: Ernest Rutherford – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1908/rutherford/lecture/

Ch1911 to Marie Curie, née Sklodowska “in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element”.

WORK: “After Marie Skłodowska Curie and Pierre Curie first discovered the radioactive elements polonium and radium, Marie continued to investigate their properties. In 1910 she successfully produced radium as a pure metal, which proved the new element's existence beyond a doubt. She also documented the properties of the radioactive elements and their compounds. Radioactive compounds became important as sources of radiation in both scientific experiments and in the field of medicine, where they are used to treat tumors.”

MLA style: Marie Curie – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1911/marie-curie/facts/

NOBEL LECTURE: Radium and the New Concepts in Chemistry by Marie Curie.

MLA style: Marie Curie – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1911/marie-curie/lecture/

Ch1935 to Frédéric Joliot and to Irène Joliot-Curie “in recognition of their synthesis of new radioactive elements”.

WORK (Joliot and Joliot-Curie): “Radiation from radioactive substances also became an important tool in investigating atoms. When Frédéric Joliot and Irene Joliot-Curie bombarded a thin piece of aluminum with alpha particles (helium atom nuclei) in 1934, a new kind of radiation was discovered that left traces inside an apparatus known as a cloud chamber. The pair discovered that the radiation from the aluminum continued even after the source of radiation was removed. This was because aluminum atoms had been converted into a radioactive isotope of phosphorus. That meant that, for the first time in history, a radioactive element had been created artificially.”

MLA style: Frédéric Joliot – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1935/joliot-fred/facts/

NOBEL LECTURE: Chemical Evidence of the Transmutation of Elements by Joliot.

MLA style: Frédéric Joliot – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1935/joliot-fred/lecture/

NOBEL LECTURE: Artificial Production of Radioactive Elements by Joliot-Curie.

MLA style: Irène Joliot-Curie – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1935/joliot-curie/lecture/

Ph1938 to Enrico Fermi “for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons”.

WORK: “Discovered in 1932, the neutron proved to be a powerful new tool for studying atoms. When Enrico Fermi irradiated heavy atoms with neutrons, these were captured by the atomic nuclei, creating new and often radioactive isotopes. In 1934, Fermi and his colleagues discovered that when neutrons are slowed down, e.g. by paraffin shielding, the interaction rate with nuclei increases. This revelation led to the discovery of many hitherto-unknown radioactive isotopes.”

MLA style: Enrico Fermi – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1938/fermi/facts/

NOBEL LECTURE: Artificial Radioactivity Produced by Neutron Bombardment by Fermi.

MLA style: Enrico Fermi – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1938/fermi/lecture/

(Source: Wikipedia commons)

Figure 13.4a. A photon coming from the left interacts with a virtual photon in an atom and produces a pair of one electron (in green) and a positron (in red).

(Source: Wikipedia commons)

Figure 13.4b. First experimental observation of a neutrino: an invisible neutrino collides with a proton, producing a muon and a pion.

Ph1906 to Joseph John Thomson “in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases”.

WORK: “The idea that electricity is transmitted by a tiny particle related to the atom was first forwarded in the 1830s. In the 1890s, J.J. Thomson managed to estimate its magnitude by performing experiments with charged particles in gases. In 1897 he showed that cathode rays (radiation emitted when a voltage is applied between two metal plates inside a glass tube filled with low-pressure gas) consist of particles— electrons—that conduct electricity. Thomson also concluded that electrons are part of atoms.”

MLA style: J.J. Thomson – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Wed. 28 Jun 2023. https://www.nobelprize.org/prizes/physics/1906/thomson/facts/

NOBEL LECTURE: Carriers of Negative Electricity by Thomson.

MLA style: J.J. Thomson – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1906/thomson/lecture/

Ph1923 to Robert Andrews Millikan “for his work on the elementary charge of electricity and on the photoelectric effect”.

WORK: “During the 1890s the theory that electricity was conveyed by a miniscule unit, the electron, gained acceptance. In 1910 Robert Millikan succeeded in precisely determining the magnitude of the electron’s charge. Small electrically charged drops of oil were suspended between two metal plates where they were subjected to the downward force of gravity and the upward attraction of an electrical field. By measuring how the various drops of oil moved about, Millikan showed that their charge always was a multiple of a precisely determined charge—the electron’s charge.”

MLA style: Robert A. Millikan – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Wed. 28 Jun 2023. https://www.nobelprize.org/prizes/physics/1923/millikan/facts/

NOBEL LECTURE: The Electron and the Light-Quant from the Experimental Point of View by Millikan.

MLA style: Robert A. Millikan – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1923/millikan/lecture/

Ph1935 to James Chadwick “for the discovery of the neutron”.

WORK:” When Herbert Becker and Walter Bothe directed alpha particles (helium nuclei) at beryllium in 1930, a strong, penetrating radiation was emitted. One hypothesis was that this could be high-energy electromagnetic radiation. In 1932, however, James Chadwick proved that it consisted of a neutral particle with about the same mass as a proton. Ernest Rutherford had earlier proposed that such a particle might exist in atomic nuclei. Its existence now proven, it was called a “neutron”.”

MLA style: James Chadwick – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1935/chadwick/facts/

NOBEL LECTURE: The Neutron and Its Properties by Chadwick.

MLA style: James Chadwick – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1935/chadwick/lecture/

Ph1936 to Carl David Anderson “for his discovery of the positron”.

WORK:” In developing quantum mechanical theory, Dirac predicted that all matter has a kind of mirror image—antimatter. A particle and its antiparticle, if charged, should have opposite charges. By studying the tracks of cosmic ray particles in a cloud chamber, in 1932 Carl Anderson discovered a positively-charged particle with a mass seemingly equal to that of an electron. Anderson’s particle was the first antiparticle proven by experiment and was named a “positron”.

MLA style: Carl D. Anderson – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1936/anderson/facts/

NOBEL LECTURE: The Production and Properties of Positrons by Anderson.

MLA style: Carl D. Anderson – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1936/anderson/lecture/

Ph1959 to Emilio Gino Segrè and to Owen Chamberlain “for their discovery of the antiproton”.

WORK (Segrè and Chamberlain): “The matter around us has a kind of mirror image—antimatter. A particle and its antiparticle have an opposite electrical charge, among other things. The electron’s antiparticle positron was the first to be discovered. With high concentrations of energy, a pair of particles and antiparticles can be created, but when a particle and an antiparticle meet, both are annihilated and their mass is converted into radiation. In a 1955 experiment with a powerful particle accelerator, Emilio Segrè and Owen Chamberlain confirmed the existence of the proton’s antiparticle, the antiproton.”

MLA style: Emilio Segrè – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1959/segre/facts/

NOBEL LECTURE: Properties of Antinucleons by Segré.

MLA style: Emilio Segrè – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1959/segre/lecture/

NOBEL LECTURE: The Early Antiproton Work by Chamberlain.

MLA style: Owen Chamberlain – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1959/chamberlain/lecture/

Ph1984 to Carlo Rubbia and Simon van der Meer "for their decisive contributions to the large project, which led to the discovery of the field particles W and Z, communicators of weak interaction".

WORK (Rubia): “According to modern physics, four fundamental forces are at work in nature. Weak interaction, which, for example, causes beta decay in atomic nuclei, is one of these. In theory, these forces are conveyed by particles—the weak interaction by W and Z particles. Carlo Rubbia proposed and led experiments that, by allowing protons and antiprotons to collide at very high speeds, would prove the existence of these particles. In this way, the existence of W and Z particles was verified in 1983.”

MLA style: Carlo Rubbia – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1984/rubbia/facts/

NOBEL LECTURE: Experimental Observation of the Intermediate Vector Bosons \(W^+\), \(W^–\) and \(Z^0\) by Rubia.

MLA style: Carlo Rubbia – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1984/rubbia/lecture/

WORK (Meer): “According to modern physics, there are four fundamental forces in nature. The weak interaction, responsible for e.g. the beta-decay of nuclei is one of them. According to the theory forces are mediated by particles: the weak interaction by the so called heavy bosons W, Z, about 100 times more massive than the proton. Simon van der Meer developed a method to accumulate a large number of energetic antiprotons in an accelerator ring. These were used in experiment where antiprotons and protons of high energy were brought to collide. In these experiments W and Z particles were discovered in 1983.”

MLA style: Simon van der Meer – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1984/meer/facts/

NOBEL LECTURE: Stochastic Cooling and the Accumulation of Antiprotons by der Meer.

MLA style: Simon van der Meer – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1984/meer/lecture/

Ph1988 to Leon M. Lederman, Melvin Schwartz and Jack Steinberger “for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino”.

WORK (Lederman, Schwartz and Steinberger): “In decays of certain elementary particles, neutrinos are produced; particles that occasionally interact with matter to produce electrons. Leon Lederman, Melvin Schwartz, and Jack Steinberger managed to create a beam of neutrinos using a high-energy accelerator. In 1962, they discovered that, in some cases, instead of producing an electron, a muon (200 times heavier than an electron) was produced, proving the existence of a new type of neutrino, the muon neutrino. These particles, collectively called “leptons”, could then be systematically classified in families.”

MLA style: Leon M. Lederman – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 20 Jul 2023. https://www.nobelprize.org/prizes/physics/1988/lederman/facts/

NOBEL LECTURE: Observations in Particle Physics from Two Neutrinos to the Standard Model by Lederman.

MLA style: Leon M. Lederman – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 20 Jul 2023. https://www.nobelprize.org/prizes/physics/1988/lederman/lecture/

NOBEL LECTURE: The First High Energy Neutrino Experiment by Schwartz.

MLA style: Melvin Schwartz – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 20 Jul 2023. https://www.nobelprize.org/prizes/physics/1988/schwartz/lecture/

NOBEL LECTURE: Experiments with High-Energy Neutrino Beams by Steinberger.

MLA style: Jack Steinberger – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 20 Jul 2023. https://www.nobelprize.org/prizes/physics/1988/steinberger/lecture/

Ph1995 "for pioneering experimental contributions to lepton physics" jointly with one half to Martin L. Perl "for the discovery of the tau lepton" and with one half to Frederick Reines "for the detection of the neutrino"

WORK (Perl): “According to modern physics, everything in the universe is composed of small building blocks—particles that can be arranged in a model with different families. Many particles do not exist in nature, but can be created in experiments where they quickly disintegrate into other particles, leaving trails behind them. In a series of experiments from 1974 to 1977 in which electrons and positrons were made to collide, Martin Perl discovered a new particle—the tau particle. The discovery meant that there was an additional family of particles alongside two previously known families.”

MLA style: Martin L. Perl – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1995/perl/facts/

NOBEL LECTURE: Reflections on the Discovery of the Tau Lepton by Perl.

MLA style: Martin L. Perl – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1995/perl/lecture/

WORK (Reines): “During the beta decay of a nucleus, a neutron is converted to a proton and an electron is produced. In studying the electron’s velocity, it was clear that this decay violated energy-conversation and other laws. It was thus proposed that an additional particle—a neutrino—was formed during beta decay. In the early 1950s, Frederick Reines passed radiation from a nuclear reactor through a water tank and discovered reactions that proved the neutrino’s existence.”

MLA style: Frederick Reines – Facts. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1995/reines/facts/

NOBEL LECTURE: The Neutrino: From Poltergeist to Particle by Reines.

MLA style: Frederick Reines – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2024. Fri. 1 Nov 2024. https://www.nobelprize.org/prizes/physics/1995/reines/lecture/

(Source: Wikipedia commons)

Figure 13.5. Radio image of a black hole in the center of galaxy Messier 87.

Ch1922 to Francis William Aston “for his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his enunciation of the whole-number rule”.

WORK: “After it became clear that elements could have different isotopes, i.e., occur in different variants with different atomic weights, Francis Aston developed the mass spectrograph in 1919 to map the different isotopes. In the mass spectrograph, beams of atoms were generated in a tube with the aid of an electrical field. When the beams passed through an electrical and magnetic field, the lighter isotopes were bent more than the heavier ones. Aston came to the conclusion that the weight of the isotopes was very close to whole-number multiples of a unit.”

MLA style: Francis W. Aston – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1922/aston/facts/

NOBEL LECTURE: Mass Spectra and Isotopes by Aston.

MLA style: Francis W. Aston – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1922/aston/lecture/

Ph1927 to Arthur Holly Compton “for his discovery of the effect named after him”.

WORK: “According to Einstein’s photoelectric effect theory, light consists of quanta, “packages” with definite energies corresponding to certain frequencies. A light quantum is called a photon. When Arthur Compton directed X-ray photons onto a metal surface in 1922, electrons were emancipated and the X-rays’ wavelength increased because some of the incident photon energy was transferred to the electrons. The experiment confirmed that electromagnetic radiation could also be described as photon particles following the laws of mechanics.”

MLA style: Arthur H. Compton – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Wed. 28 Jun 2023. https://www.nobelprize.org/prizes/physics/1927/compton/facts/

NOBEL LECTURE: X-rays as a Branch of Optics by Compton.

MLA style: Arthur H. Compton – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1927/compton/lecture/

Ph1937 to Clinton Joseph Davisson and George Paget Thomson “for their experimental discovery of the diffraction of electrons by crystals”.

WORK (Davisson and Thomson): ”In the beginning of the 19th century, quantum physics evolved from the idea that energy is conveyed in only certain fixed amounts. An early finding indicated that light can be regarded as both waves and particles. Later it was proposed that matter, such as electrons, also can be described as both waves and particles. In 1927 Clinton Davisson and G.P. Thomson demonstrated, independently of one another, that electrons could be described as waves. When an electron beam passed through a nickel crystal, diffraction patterns appeared.”

MLA style: Clinton Davisson – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Wed. 28 Jun 2023. https://www.nobelprize.org/prizes/physics/1937/davisson/facts/

NOBEL LECTURE: The Discovery of Electron Waves by Davisson.

MLA style: Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/1937/davisson/lecture/

NOBEL LECTURE: Electronic Waves by Thomson.

MLA style: Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1937/thomson/lecture/

Ch1944 to Otto Hahn “for his discovery of the fission of heavy nuclei”.

WORK: “The discovery of the neutron in 1932 provided a powerful new tool for investigating atoms. When Otto Hahn and Fritz Strassman irradiated uranium with neutrons in 1939, they created barium, which was far too light an element to be a decay product of uranium. Hahn's long-time colleague, Lise Meitner, and her nephew, Otto Frisch, tackled the problem from a theoretical standpoint and proved that the uranium nucleus had been split. The phenomenon, later called “fission”, proved important in developing nuclear weapons and energy.”

MLA style: Otto Hahn – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1944/hahn/facts/

NOBEL LECTURE: From the Natural Transmutations of Uranium to Its Artificial Fission by Hahn.

MLA style: Otto Hahn – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/chemistry/1944/hahn/lecture/

Ph1951 to Sir John Douglas Cockcroft and to Ernest Thomas Sinton Walton “for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles”.

WORK (Cokcroft): ”Ernest Rutherford used alpha particles from radioactive elements to study nuclear reactions and used his findings to convert nitrogen into oxygen. However, only a very few nuclear reactions could be achieved using alpha particles. John Cockcroft and Ernest Walton developed a device, an accelerator, to generate more penetrating radiation. Using a strong electric field, protons were accelerated to high velocities. In 1932, they bombarded lithium with protons, causing their nuclei to split and producing two alpha particles.”

MLA style: John Cockcroft – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1951/cockcroft/facts/

NOBEL LECTURE: Experiments on the Interaction of High-Speed Nucleons with Atomic Nuclei by Cockcroft.

MLA style: John Cockcroft – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1951/cockcroft/lecture/

WORK (Walton): “Ernest Rutherford used alpha particles from radioactive elements to study nuclear reactions and used his findings to convert nitrogen into oxygen. However, only a very few nuclear reactions could be achieved using alpha particles. Ernest Walton and John Cockcroft developed a device, an accelerator, to generate more penetrating radiation. Using a strong electric field, protons were accelerated to high velocities. In 1932, they bombarded lithium with protons, causing their nuclei to split and producing two alpha particles.

MLA style: Ernest T.S. Walton – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1951/walton/facts/

NOBEL LECTURE: The Artificial Production of Fast Particles by Walton.

MLA style: Ernest T.S. Walton – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Thu. 3 Aug 2023. https://www.nobelprize.org/prizes/physics/1951/walton/lecture/

Ph2002 to Raymond Davis Jr. and Masatoshi Koshiba “for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos” and to Riccardo Giacconi “for pioneering contributions to astrophysics, which have led to the discovery of cosmic X-ray sources”.

WORK (Davis): “In certain nuclear reactions (such as when protons combine to form helium nuclei) elusive particles called neutrinos are created. Raymond Davies wanted to detect neutrinos in radiation from space to confirm the theory that this kind of nuclear reaction is the source of the sun’s energy. Beginning in the 1960s, he placed a large tank containing a chlorine-rich liquid inside a mine. In rare cases, a neutrino interacted with a chlorine atom to form an argon atom. By counting these argon atoms, neutrinos from space could be detected.”

MLA style: Raymond Davis Jr. – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 30 Jun 2023. https://www.nobelprize.org/prizes/physics/2002/davis/facts/

NOBEL LECTURE: A Half-Century with Solar Neutrinos by Davis.

MLA style: Raymond Davis Jr. – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2002/davis/lecture/

WORK (Koshiba): “Certain nuclear reactions, including those where hydrogen atoms combine with helium, form elusive particles called neutrinos. By proving the existence of neutrinos in cosmic radiation, Raymond Davis showed that the sun's energy originates from such nuclear reactions. From 1980, Masatoshi Koshiba provided further proof of this through measurements taken inside an enormous water tank within a mine. In rare cases, neutrinos react with atomic nuclei in water, creating an electron and thus a flash of light that can be detected.”

MLA style: Masatoshi Koshiba – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2002/koshiba/facts/

NOBEL LECTURE: Birth of Neutrino Astrophysics by Koshiba.

MLA style: Masatoshi Koshiba – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2002/koshiba/lecture/

WORK (Giacconi): “Stars and galaxies emit not only visible light, but also X-rays. However, the X-rays dissipate as they pass through the earth’s atmosphere, so X-rays from the cosmos have to be studied by means of telescopes in satellites. Beginning in the 1960s, Riccardo Giacconi made several pivotal contributions to the development of such telescopes. With the telescopes, he discovered X-ray sources outside our own solar system, cosmic background radiation with X-ray wavelengths as well as X-ray sources that probably contain black holes.”

MLA style: Riccardo Giacconi – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 30 Jun 2023. https://www.nobelprize.org/prizes/physics/2002/giacconi/facts/

NOBEL LECTURE: The Dawn of X-Ray Astronomy by Giacconi.

MLA style: Riccardo Giacconi – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2002/giacconi/lecture/

Ph2015 to Takaaki Kajita and Arthur B. McDonald “for the discovery of neutrino oscillations, which shows that neutrinos have mass”.

WORK (Kajita): “The Standard Model used by modern physics has three types of a very small and elusive particle called the neutrino. In the Super-Kamiokande detector, an experimental facility in a mine in Japan in 1998, Takaaki Kajita detected neutrinos created in reactions between cosmic rays and the Earth’s atmosphere. Measurements showed deviations, which were explained by the neutrinos switching between the different types. This means that they must have mass. The Standard Model, however, is based on neutrinos lacking mass and the model must be revised.”

MLA style: Takaaki Kajita – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 30 Jun 2023. https://www.nobelprize.org/prizes/physics/2015/kajita/facts/

NOBEL LECTURE: Discovery of Atmospheric Neutrino Oscillations by Kajita.

MLA style: Takaaki Kajita – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2015/kajita/lecture/

WORK (McDonald): “The Standard Model used by modern physics has three types of a very small and elusive particle called the neutrino. In an experimental facility in a mine in Canada in 2000, Arthur McDonald studied neutrinos created in nuclear reactions in the sun. Measurements showed deviations, which were explained by the neutrinos switching between the different types. This means that they must have mass. The Standard Model, however, is based on neutrinos lacking mass and the model must be revised.”

MLA style: Arthur B. McDonald – Facts. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 30 Jun 2023. https://www.nobelprize.org/prizes/physics/2015/mcdonald/facts/

NOBEL LECTURE: The Sudbury Neutrino Observatory: Observation of Flavor Change for Solar Neutrinos by McDonald.

MLA style: Arthur B. McDonald – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Fri. 4 Aug 2023. https://www.nobelprize.org/prizes/physics/2015/mcdonald/lecture/

Ph2020 to Roger Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity” and to Reinhard Genzel and Andrea Ghez “for the discovery of a supermassive compact object at the centre of our galaxy”.

WORK (Genzel and Ghez): “A black hole is a supermassive compact object with a gravitational force so large that nothing, not even light, can escape from it. Since nothing, not even light, can escape black holes, they can only be observed by the radiation and the movement of nearby objects. Since the 1990s, Reinhard Genzel and Andrea Ghez with their respective research teams, have developed and refined techniques for studying the movement of stars. Observations of stars in the area around Sagittarius A* in the middle of our galaxy, the Milky Way, revealed a super massive black hole.”

MLA style: Reinhard Genzel – Facts – 2020. NobelPrize.org. Nobel Prize Outreach AB 2023. Sat. 1 Jul 2023. https://www.nobelprize.org/prizes/physics/2020/genzel/facts/

NOBEL LECTURE: A Forty Year Journey by Genzel.

MLA style: Reinhard Genzel – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Mon. 17 Jul 2023. https://www.nobelprize.org/prizes/physics/2020/genzel/lecture/

NOBEL LECTURE: From the Possibility to the Certainty of a Supermassive Black Hole by Ghez.

MLA style: Andrea Ghez – Nobel Lecture. NobelPrize.org. Nobel Prize Outreach AB 2023. Mon. 17 Jul 2023. https://www.nobelprize.org/prizes/physics/2020/ghez/lecture/


Next: 13.3. Contributions made by theoretical approaches.