DOCSLIB.ORG

Atomic Theory

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Atomic Theory History of the Modern Atomic Theory Chemistry The Atomic Theory • What do we know about atoms? • We know that atoms are composed of protons, neutrons, and electrons. The protons and neutrons comprise almost the entire mass of the atom and make up the nucleus. The electrons are in energy levels outside the nucleus residing in orbitals which contain a maximum of 2 electrons. The proton gives the atom its identity, but it is the electron which gives the atom its chemical properties. We know that elements consist of different isotopes, some of which are radioactive. • But HOW do we know all this stuff? • There have been MANY scientists studying the atom and radioactivity and their studies have cumulated in this vast knowledge of the atom and its properties. Democritus of Abdera • First to produce an elaborate and systematic view of the atomic theory. • Said that all matter is composed of tiny, INDIVISIBLE particles called atomos (today, called atoms) John Dalton • (1766 – 1844) • A Quaker and English schoolteacher who discovered he was colorblind. • Devised the atomic theory of matter: 1. All elements are composed of atoms. 2. All of the atoms of an element are identical and are different from the atoms of any other element. 3. Atoms are not created or destroyed in a chemical reaction. 4. Compounds always have the same numbers and kinds of atoms. • Published the first list of atomic weights and symbols which gave chemistry a language of its own. Joseph John Thomson • J.J. Thomson (1856 – 1940) • Discovered that atoms were made of pieces, not “indivisible” as previously thought. • Used cathode ray tube • Discovered that cathode rays are composed of negative particles that called ELECTRONS. Thomson’s Cathode Ray Tube Robert Andrews Millikan • Born March 22, 1868 in Morrison, Illinois • Determined the charge on an electron in his oil drop experiment • Showed that the electron is an extremely light particle Millikan’s Oil-Drop Experiment Ernest Rutherford • (1871 – 1937) • Was a research student under J.J. Thomson at Cambridge University • Gold Foil Experiment: all of an atom’s + charge is concentrated in a small core in the center- he called it the nucleus. • First model of the atom with a nucleus in the center and electrons on the outside. (Planetary model of the atom) • The atom is so small that it would take over 5 million atoms side-by- side to go across your notebook paper ; he postulated the nucleus to have almost all of the mass of the atom even though the nucleus is 1000x smaller than the atom itself. • Also studied radioactivity • Discovered and named alpha and beta radiation James Chadwick • 1891-1974 • English physicist • Worked with Rutherford • Imprisoned at beginning of WWI until Geiger’s laboratory interceded for his release. • Discovered the particle in the nucelus that has no charge- the neutron • Determined the mass of the neutron= 1.0067. Niels Henrik David Bohr • Born in Copenhagen on Oct. 7, 1885 (died 1962) • During the Nazi occupation of Denmark, Bohr escaped to Sweden where he became associated with the Atomic Energy Project with Albert Einstein. • Added to Rutherford’s model of the atom by including energy levels, outside of the nucleus, where electrons are located. • Said that electrons “jump” to higher energy levels when they absorb energy Benjamin Franklin • Franklin was well known for his studies on electricity and as well as his many inventions such as the Franklin stove, swim fins, glass harmonica, and bifocals. • Said there are two kinds of charges- (+) and (-). • Said that like charges repel and opposite charges attract (Law of Electrostatics) • Said that lightning is simply static electricity Henri Becquerel • 1852 – 1908 • Father of Radioactivity • Accidentally discovered radioactivity – he placed some Uranium on some unexposed film. He found an image on the film showing the crystalline structure of the uranium. He concluded the uranium emitted radiation which could penetrate paper opaque to light. Uranium could do this without an external source of energy. Marie Curie • Born Marya Sklodowska in Warsaw, Poland on Nov. 7, 1867; died 1934 • Dreamed of a scientific career, a concept inconceivable for a woman at that time. Lack of finances force her to become a private tutor. • Self-taught, she passed a physics degree with flying colors. Studied for her physics doctorate attempting to further study the effects and energy of uranium’s rays. • Married Pierre Curie, with whom she shared a laboratory. • She discovered polonium and radium in 1898. • She along with her husband and Henri Becquerel was awarded the Nobel Prize for Physics for their work in radioactivity. (1903) • In 1911, she was denied entrance into the Academy of Science, yet soon after she was honored with a Nobel Prize for Chemistry for determining the atomic weight of radium. Dmitri Ivanovich Mendeleev (1834 – 1907) • Born in Siberia, the youngest of 14 children (actual number varies from 11 to 17 depending on the source) • Very poor, but his mother saved money for him to attend the university. • First learned about chemistry by working in the glass factory where his mother worked. • Gave us the modern periodic table (his was by increasing atomic masses, where ours today is arranged by increasing atomic numbers. • Left spaces for elements which had not yet been discovered, but was able to predict what properties they would have by their location in his table. Henry Moseley • (1887 – 1915) • British chemist who studied under Rutherford. • Said that atoms contain a unique (+) charge in their nucleus and named it proton. • Said that protons give an element its identity (# of protons = Atomic #) • With the discovery of isotopes he determine the atomic weight was not the major player in the periodic law, but it was the atomic number. This discovery made the few problems with Mendeleev’s periodic table disappear. • The modern periodic table is now based on the atomic number of the elements. Albert Einstein • (1879 – 1955) in Germany • Studied violin & Judaism from age 6 – 13 • Failed an exam which would have allowed him to study as an electrical engineer • Renounced German citizenship in 1896, became a Swiss citizen in 1901 remaining stateless for these number of years. • In 1900 graduated as a teacher of mathematics and physics. • In 1905 showed how mass and energy were equivalent. (E = mc2) • Explained the photoelectric effect using Planck’s theory: light causes electrons to be ejected when it hits a piece of metal. There is a minimum frequency (energy) of light needed to eject an electron. • Said that light is composed of photon – discrete packets of energy • Received Nobel Prize in 1921 for his work on the photoelectric effect. Albert Einstein • Left Germany in Dec. 1932 as the Nazis came to power, never to return. • In 1940 Einstein became a US citizen, retaining his Swiss citizenship. • In 1944, he made a contribution to the war by handwriting his 1905 paper on special relativity and putting it up for auction. It raised $6,000,000. It resides today in the Library of Congress. • In 1952, after the death of the first President of Israel, the Israeli government offered him this position, of which he refused. Antoine-Laurent Lavoisier • Antoine Lavoisier (1743 – 1794) • Called the “Father of Modern Chemistry” because of his careful experiments and precise measurements. • French chemistry responsible for the Law of Conservation of Matter: “Matter, like energy, can neither be created or destroyed, only changed from one form to another.” • Major tool was the balance • Recognized the role that oxygen plays in burning and rusting • He was beheaded during the French Revolution. Joseph Proust • 1754-1826 • French chemist • “steadiness” of the composition of chemical compounds • Said that compounds always contain the same elements in the same proportions (Law of Definite Proportions) Michael Faraday • 1791-1867 • English chemist and physicist • Said that atoms are related to electricity, atoms contain particles that have electric charges The Infamous Kite Experiment Max Planck • 1858-1947 • German physicist • Stated the relationship between energy and frequency in his equation: E= hv. • Frequency and energy are directly proportional • Defined quantum: unique, fixed amount of energy absorbed and/or reflected by an object • Founder of Quantum Theory Colleagues • Albert Einstein and Niels Bohr. Atoms in a Crystal • Image of Silicon atoms arranged on a face of a crystal. This image was made by a Scanning Tunneling Microscope, a device that “feel” the cloud of electrons that form the outer surface of atoms, rather like a phonograph needle feels the grooves in a record. • Einstein’s studies and papers gave one of the first convincing proofs that atoms do exist as real objects. Einstein’s Letter to FDR • Einstein wrote a letter attempting to alert President Roosevelt of the severity of proceeding with nuclear reactions as a war tool. Arthur Compton • 1892-1962 • Said that light consists of tiny particles called photons • Said that photons could collide with electrons like two balls colliding with each other Werner Heisenberg • 1901-1976 • German physicist and one of the founders of quantum mechanics • Worked with Neils Bohr • Discovered Heisenberg Uncertainty Principle: position and momentum of a moving object cannot be known at the same time • Nobel Prize in Physics in 1932 Louie de Broglie • 1892-1987 • Said that moving particles exhibit wavelike behavior Wolfgang Pauli • (1900 – 1958) • Studied under Niels Bohr. • In 1924 proposed the quantum spin number for electrons and in 1925 gave the scientific world his best known work, the Pauli Exclusion Principle: • Said that electrons can have only one of two spins. • Said that only two electrons one orbital and that each electron in an orbital must have opposite spins. • Received the Nobel Prize in 1945. Group Portrait What did I do? • Antoine Lavoisier What important contributions did I make? • Marie Curie E = mc2 • Albert Einstein • What do you know about me? What did I contribute to chemistry? • Dmriti Mendeleev Together we made something Great! What is this? • Who used it to discover the electron?.
Load more

Recommended publications
  • Harry Truman, the Atomic Bomb and the Apocalyptic Narrative
    Volume 5 | Issue 7 | Article ID 2479 | Jul 12, 2007 The Asia-Pacific Journal | Japan Focus The Decision to Risk the Future: Harry Truman, the Atomic Bomb and the Apocalyptic Narrative Peter J. Kuznick The Decision to Risk the Future: Harry stressed that the future of mankind would be Truman, the Atomic Bomb and theshaped by how such bombs were used and Apocalyptic Narrative subsequently controlled or shared.[3] Truman recalled Stimson “gravely” expressing his Peter J. Kuznick uncertainty about whether the U.S. should ever use the bomb, “because he was afraid it was so I powerful that it could end up destroying the whole world.” Truman admitted that, listening In his personal narrative Atomic Quest, Nobel to Stimson and Groves and reading Groves’s Prize-winning physicist Arthur Holly Compton, accompanying memo, he “felt the same who directed atomic research at the University fear.”[4] of Chicago’s Metallurgical Laboratory during the Second World War, tells of receiving an urgent visit from J. Robert Oppenheimer while vacationing in Michigan during the summer of 1942. Oppenheimer and the brain trust he assembled had just calculated the possibility that an atomic explosion could ignite all the hydrogen in the oceans or the nitrogen in the atmosphere. If such a possibility existed, Compton concluded, “these bombs must never be made.” As Compton said, “Better to accept the slavery of the Nazis than to run a chance of drawing the final curtain on mankind.”[1] Certainly, any reasonable human being could be expected to respond similarly. Three years later, with Hitler dead and the Nazis defeated, President Harry Truman faced Truman and Byrnes en route to Potsdam, July a comparably weighty decision.
    [Show full text]
  • Atomic Physics & Quantum Effects
    KEY CONCEPTS ATOMIC PHYSICS & QUANTUM EFFECTS 1. PHOTONS & THE PHOTOELECTRIC EFFECT Max Planck explained blackbody radiation with his quantum hypothesis, which states that the energy of a thermal oscillator, Eosc, is not continuous, but instead is a discrete quantity given by the equation: Eosc = nhf n = 1, 2, 3,... where f is the frequency and h is a constant now known as Planck’s constant. Albert Einstein extended the idea by adding that all emitted radiation is quantized. He suggested that light is composed of discrete quanta, rather than of waves. According to his theory, each particle of light, known as a photon, has an energy E given by: E = hf Einstein’s theory helped him explain a phenomenon known as the photoelectric effect, in which a photon of light strikes a photosensitive material and causes an electron to be ejected from the material. A photocell constructed from photosensitive material can produce an electrical current when light shines on it. The kinetic energy, K, of a photoelectron displaced by a photon of energy, hf, is given by: K = hf - φ where the work function, φ, is the minimum energy needed to free the electron from the photosensitive material. No photoemission occurs if the frequency of the incident light falls below a certain cutoff frequency – or threshold frequency – given by: φ f0 = h Einstein's theory explained several aspects of the photoelectric effect that could not be explained by classical theory: • The kinetic energy of photoelectrons is dependent on the light’s frequency. • No photoemission occurs for light below a certain threshold frequency.
    [Show full text]
  • I. I. Rabi Papers [Finding Aid]. Library of Congress. [PDF Rendered Tue Apr
    I. I. Rabi Papers A Finding Aid to the Collection in the Library of Congress Manuscript Division, Library of Congress Washington, D.C. 1992 Revised 2010 March Contact information: http://hdl.loc.gov/loc.mss/mss.contact Additional search options available at: http://hdl.loc.gov/loc.mss/eadmss.ms998009 LC Online Catalog record: http://lccn.loc.gov/mm89076467 Prepared by Joseph Sullivan with the assistance of Kathleen A. Kelly and John R. Monagle Collection Summary Title: I. I. Rabi Papers Span Dates: 1899-1989 Bulk Dates: (bulk 1945-1968) ID No.: MSS76467 Creator: Rabi, I. I. (Isador Isaac), 1898- Extent: 41,500 items ; 105 cartons plus 1 oversize plus 4 classified ; 42 linear feet Language: Collection material in English Location: Manuscript Division, Library of Congress, Washington, D.C. Summary: Physicist and educator. The collection documents Rabi's research in physics, particularly in the fields of radar and nuclear energy, leading to the development of lasers, atomic clocks, and magnetic resonance imaging (MRI) and to his 1944 Nobel Prize in physics; his work as a consultant to the atomic bomb project at Los Alamos Scientific Laboratory and as an advisor on science policy to the United States government, the United Nations, and the North Atlantic Treaty Organization during and after World War II; and his studies, research, and professorships in physics chiefly at Columbia University and also at Massachusetts Institute of Technology. Selected Search Terms The following terms have been used to index the description of this collection in the Library's online catalog. They are grouped by name of person or organization, by subject or location, and by occupation and listed alphabetically therein.
    [Show full text]
  • Arthur Holly Compton
    Arthur Holly Compton ALSO LISTED IN Physicists ALSO KNOWN AS Arthur Holly Compton FAMOUS AS Nobel Prize Laureate in Physics NATIONALITY American Famous American Men RELIGION Baptist BORN ON 10 September 1892 AD Famous 10th September Birthdays ZODIAC SIGN Virgo Virgo Men BORN IN Wooster, Ohio, USA DIED ON 15 March 1962 AD PLACE OF DEATH Berkeley, California, USA FATHER Elias Compton MOTHER Otelia Catherine SIBLINGS Karl Taylor Compton, Wilson Martindale Compton SPOUSE: Betty Charity McCloskey CHILDREN Arthur Allen Compton, John Joseph Compton EDUCATION University of Cambridge, The College of Wooster, Princeton University DISCOVERIES / INVENTIONS Compton Effect AWARDS: Nobel Prize for Physics (1927) Matteucci Medal (1930) Franklin Medal (1940) Hughes Medal (1940) Arthur Holly Compton was a renowned American physicist who first rose to fame with his famous revolutionary discovery of the Compton Effect for which he also won the Nobel Prize in Physics. This discovery confirmed the dual nature of electromagnetic radiation as both a wave and a particle. Thomson was initially interested in astronomy before he shifted his focus to the study of quantum physics. He started his research in Cavendish Laboratory of Cambridge University and this research led to the discovery of Compton Effect. Later on, during the Second World War, Compton became head of the Manhattan Project’s Metallurgical Laboratory. Manhattan Project developed the first nuclear weapons of the world and Compton played a key role in it. He also served as Chancellor of Washington University in St. Louis. Under his leadership, the University made remarkable academic progress; the university formally desegregated its undergraduate divisions, named its first female full professor, and enrolled a record number of students.
    [Show full text]
  • RHIC Begins Smashing Nuclei
    NEWS RHIC begins smashing nuclei Gold at STAR - side view of a collision of two 30 GeV/nucleon gold End view in the STAR detector of the same collision looking along beams in the STAR detector at the Relativistic Heavy Ion Collider at the direction of the colliding beams. Approximately 1000 tracks Brookhaven. were recorded in this event On Monday 12 June a new high-energy laboratory director for RHIC. It was a proud rings filled, the ions will be whipped to machine made its stage debut as operators in moment for Ozaki, who returned to 70 GeV/nucleon. With stable beams coasting the main control room of Brookhaven's Brookhaven from Japan to oversee the con­ around the rings, the nuclei collide head-on, Relativistic Heavy Ion Collider (RHIC) finally struction and commissioning of this eventually at the rate of tens of thousands of declared victory over their stubborn beams. challenging machine. collisions per second. Several weeks before, Derek Lowenstein, The high temperatures and densities Principal RHIC components were manufac­ chairman of the laboratory's collider-acceler­ achieved in the RHIC collisions should, for a tured by industry, in some cases through ator department, had described repeated fleeting moment, allow the quarks and gluons co-operative ventures that transferred tech­ attempts to get stable beams of gold ions to roam in a soup-like plasma - a state of nology developed at Brookhaven to private circulating in RHIC's two 3.8 km rings as "like matter that is believed to have last existed industry. learning to drive at the Indy 500!".
    [Show full text]
  • The Adventures of a Citizen Scientist
    The Adventures of a Citizen Scientist Perhaps one never knows one’s parents, really knows them. You never know their early lives and, as a kid, you’re living inside your own skin, not theirs. After that you’re out of there. Growing up in Chicago, I never knew my dad was famous. He was just a firm, affectionate, if too busy father figure, who loved music and the outdoors, played tennis better than I could, was awfully good with tools, and could explain scientific ideas so well that I almost understood them. I knew he was a physicist and taught at the University, and he and mother often took me on lecture or research trips, but I didn’t know what it was all about. During the war, when he was one of those in charge of the bomb project and we’d moved to Oak Ridge, he was just a hard-working ordinary man doing a job like everybody else. August 6th, 1945, brought a dramatically different perspective, as you might expect. My father was suddenly a national and world figure. That fall, as I went off to college, I began to hear something of his achievements — not only the bomb, but the cosmic ray studies and the Nobel Prize, with all that seemed to entail. At that moment, too, he’d become Chancellor of Washington University in St. Louis, and my college was his college, where his father had been Professor of Philosophy and Psychology and Dean. I was in Wooster, Ohio, the town in which my father had grown up, with his childhood house just down College Avenue.
    [Show full text]
  • Otto Stern Annalen 4.11.11
    (To be published by Annalen der Physik in December 2011) Otto Stern (1888-1969): The founding father of experimental atomic physics J. Peter Toennies,1 Horst Schmidt-Böcking,2 Bretislav Friedrich,3 Julian C.A. Lower2 1Max-Planck-Institut für Dynamik und Selbstorganisation Bunsenstrasse 10, 37073 Göttingen 2Institut für Kernphysik, Goethe Universität Frankfurt Max-von-Laue-Strasse 1, 60438 Frankfurt 3Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6, 14195 Berlin Keywords History of Science, Atomic Physics, Quantum Physics, Stern- Gerlach experiment, molecular beams, space quantization, magnetic dipole moments of nucleons, diffraction of matter waves, Nobel Prizes, University of Zurich, University of Frankfurt, University of Rostock, University of Hamburg, Carnegie Institute. We review the work and life of Otto Stern who developed the molecular beam technique and with its aid laid the foundations of experimental atomic physics. Among the key results of his research are: the experimental test of the Maxwell-Boltzmann distribution of molecular velocities (1920), experimental demonstration of space quantization of angular momentum (1922), diffraction of matter waves comprised of atoms and molecules by crystals (1931) and the determination of the magnetic dipole moments of the proton and deuteron (1933). 1 Introduction Short lists of the pioneers of quantum mechanics featured in textbooks and historical accounts alike typically include the names of Max Planck, Albert Einstein, Arnold Sommerfeld, Niels Bohr, Max von Laue, Werner Heisenberg, Erwin Schrödinger, Paul Dirac, Max Born, and Wolfgang Pauli on the theory side, and of Wilhelm Conrad Röntgen, Ernest Rutherford, Arthur Compton, and James Franck on the experimental side. However, the records in the Archive of the Nobel Foundation as well as scientific correspondence, oral-history accounts and scientometric evidence suggest that at least one more name should be added to the list: that of the “experimenting theorist” Otto Stern.
    [Show full text]
  • Chicago Physics One
    CHICAGO PHYSICS ONE 3:25 P.M. December 02, 1942 “All of us... knew that with the advent of the chain reaction, the world would never be the same again.” former UChicago physicist Samuel K. Allison Physics at the University of Chicago has a remarkable history. From Albert Michelson, appointed by our first president William Rainey Harper as the founding head of the physics department and subsequently the first American to win a Nobel Prize in the sciences, through the mid-20th century work led by Enrico Fermi, and onto the extraordinary work being done in the department today, the department has been a constant source of imagination, discovery, and scientific transformation. In both its research and its education at all levels, the Department of Physics instantiates the highest aspirations and values of the University of Chicago. Robert J. Zimmer President, University of Chicago Welcome to the inaugural issue of Chicago Physics! We are proud to present the first issue of Chicago Physics – an annual newsletter that we hope will keep you connected with the Department of Physics at the University of Chicago. This newsletter will introduce to you some of our students, postdocs and staff as well as new members of our faculty. We will share with you good news about successes and recognition and also convey the sad news about the passing of members of our community. You will learn about the ongoing research activities in the Department and about events that took place in the previous year. We hope that you will become involved in the upcoming events that will be announced.
    [Show full text]
  • Report and Opinion 2016;8(6) 1
    Report and Opinion 2016;8(6) http://www.sciencepub.net/report Beyond Einstein and Newton: A Scientific Odyssey Through Creation, Higher Dimensions, And The Cosmos Manjunath R Independent Researcher #16/1, 8 Th Main Road, Shivanagar, Rajajinagar, Bangalore: 560010, Karnataka, India [email protected], [email protected] “There is nothing new to be discovered in physics now. All that remains is more and more precise measurement.” : Lord Kelvin Abstract: General public regards science as a beautiful truth. But it is absolutely-absolutely false. Science has fatal limitations. The whole the scientific community is ignorant about it. It is strange that scientists are not raising the issues. Science means truth, and scientists are proponents of the truth. But they are teaching incorrect ideas to children (upcoming scientists) in schools /colleges etc. One who will raise the issue will face unprecedented initial criticism. Anyone can read the book and find out the truth. It is open to everyone. [Manjunath R. Beyond Einstein and Newton: A Scientific Odyssey Through Creation, Higher Dimensions, And The Cosmos. Rep Opinion 2016;8(6):1-81]. ISSN 1553-9873 (print); ISSN 2375-7205 (online). http://www.sciencepub.net/report. 1. doi:10.7537/marsroj08061601. Keywords: Science; Cosmos; Equations; Dimensions; Creation; Big Bang. “But the creative principle resides in Subaltern notable – built on the work of the great mathematics. In a certain sense, therefore, I hold it astronomers Galileo Galilei, Nicolaus Copernicus true that pure thought can
    [Show full text]
  • James Chadwick and E.S
    What is the Universe Made Of? Atoms - Electrons Nucleus - Nucleons Antiparticles And ... http://www.parentcompany.com/creation_explanation/cx6a.htm What Holds it Together? Gravitational Force Electromagnetic Force Strong Force Weak Force Timeline - Ancient 624-547 B.C. Thales of Miletus - water is the basic substance, knew attractive power of magnets and rubbed amber. 580-500 B.C. Pythagoras - Earth spherical, sought mathematical understanding of universe. 500-428 B.C. Anaxagoras changes in matter due to different orderings of indivisible particles (law of the conservation of matter) 484-424 B.C. Empedocles reduced indivisible particles into four elements: earth, air, fire, and water. 460-370 B.C. Democritus All matter is made of indivisible particles called atoms. 384-322 B.C. Aristotle formalized the gathering of scientific knowledge. 310-230 B.C. Aristarchus describes a cosmology identical to that of Copernicus. 287-212 B.C. Archimedes provided the foundations of hydrostatics. 70-147 AD Ptolemy of Alexandria collected the optical knowledge, theory of planetary motion. 1214-1294 AD Roger Bacon To learn the secrets of nature we must first observe. 1473-1543 AD Nicholaus Copernicus The earth revolves around the sun Timeline – Classical Physics 1564-1642 Galileo Galilei - scientifically deduced theories. 1546-1601, Tycho Brahe accurate celestial data to support Copernican system. 1571-1630, Johannes Kepler. theory of elliptical planetary motion 1642-1727 Sir Isaac Newton laws of mechanics explain motion, gravity . 1773-1829 Thomas Young - the wave theory of light and light interference. 1791-1867 Michael Faraday - the electric motor, and electromagnetic induction, electricity and magnetism are related. electrolysis, conservation of energy.
    [Show full text]
  • Wolfgang Pauli
    W OLFGANG P A U L I Exclusion principle and quantum mechanics Nobel Lecture, December 13, 1946 The history of the discovery of the « exclusion principle », for which I have received the honor of the Nobel Prize award in the year 1945, goes back to my students days in Munich. While, in school in Vienna, I had already ob- tained some knowledge of classical physics and the then new Einstein rel- ativity theory, it was at the University of Munich that I was introduced by Sommerfeld to the structure of the atom - somewhat strange from the point of view of classical physics. I was not spared the shock which every physicist, accustomed to the classical way of thinking, experienced when he came to know of Bohr’s « basic postulate of quantum theory » for the first time. At that time there were two approaches to the difficult problems con- nected with the quantum of action. One was an effort to bring abstract order to the new ideas by looking for a key to translate classical mechanics and electrodynamics into quantum language which would form a logical gen- eralization of these. This was the direction which was taken by Bohr’s « correspondence principle ». Sommerfeld, however, preferred, in view of the difficulties which blocked the use of the concepts of kinematical models, a direct interpretation, as independent of models as possible, of the laws of spectra in terms of integral numbers, following, as Kepler once did in his investigation of the planetary system, an inner feeling for harmony. Both methods, which did not appear to me irreconcilable, influenced me.
    [Show full text]
  • ALVAREZ Adventures of a Physicist by Luis W. Alvarez Basic Books
    ALVAREZ Adventures of a Physicist By Luis W. Alvarez Basic Books. 292 pp. $19.95 RABI Scientist and Citizen By John S. Rigden Basic Books. 302 pp. $21.95 Isidor Isaac, Sabi and Luis W. Alvarez By Alan Lightman NE SENSES Luis Alvarez' deep regret that he has been praised only by the greatest physicists alive, that Rutherford and Faraday and Newton cannot find their way to Berke- 0ley to celebrate his work. Resigned to present and fu- ture admirers, Alvarez tells us in his autobiography, Alvarez, that he had the longest Nobel Prize citation ever, was the first physicist to win the National Medal of Science, the first to use cosmic rays for a practical died out. Then he helped propose that the tnceum naa purpose, the first civilian to land an airplane under ra-, come from a giant asteroid, which threw dust in the air dar control (using the first ground-controlled approach and blocked out the sun for several years. system, which. he invented). Once our eyes have ad- Alvarez is among a handful of physicists who have, justed to this incandescent egotism, we indeed see a by their personal force, created schools, surrounding genius, who eventually endears himself with his aston- themselves with talented young apprentices who later ishing honesty. Alvarez joins the happy company of sally forth with the know-how and style of their mas- Freeman Dyson's Disturbing the Universe and Richard ter. John Wheeler was also one of these gurus. Robert Feynman's Surely You're Joking, Mr. Feynnulti!, all Oppenheimer was another.
    [Show full text]