DOCSLIB.ORG

Hydrogen Atom IV- Real System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Hydrogen Atom IV- Real System Real hydrogen atom Masatsugu Sei Suzuki Department of Physics, SUNY at Binghamton (Date: February 04, 2016) Willis Eugene Lamb, Jr. (July 12, 1913 – May 15, 2008) was an American physicist who won the Nobel Prize in Physics in 1955 together with Polykarp Kusch "for his discoveries concerning the fine structure of the hydrogen spectrum". Lamb and Kusch were able to precisely determine certain electromagnetic properties of the electron (see Lamb shift). Lamb was a professor at the University of Arizona College of Optical Sciences. http://en.wikipedia.org/wiki/Willis_Lamb 1 Fig. From the note on quantum mechanics (E. Fermi). p.117. E. Fermi, Note on Quantum Mechanics (The Univversity of Chicago, 1961). The corrections to the Bohr energy are called the fine structure. They are all relativistic in nature. The energy of the electron in hydrogen can be expressed in terms of the fine structure constant, with the use of the perturbation theory. To the order of 2 : 1 2 E (0) m c2 , n 2 e n2 To the order of 4 : 1 1 3 E (1) E (0) 2 ( ) for l 0 n n n j 1/ 2 4n 1 3 E (1) E ( 0 ) 2 (1 ) for l 0 n n n 4n To the order of 5 : 2 the expression of the frequency for the Lamb shift (the non-relativistic case) (for n = 2), can be expressed as 5 3 mec 1 2 ln( 2 ) = 1038.27 MHz ≈ 1057 MHz (experimental value). 12 c 8.9 ___________________________________________________________________________ 1. Bohr model According to the Bohr model, the electron energy of the hydrogen atom is given by 2 2 (0) e E0 1 2 En 2 2 mec 2 , 2n aB n 2 n 2 2 ˆ pˆ e (0) H 0 nlm ( ) nlm En nlm , 2me rˆ where 2 4 2 4 e mee mec e 1 2 2 E0 2 2 2 mec 2aB 2 2 c 2 E0 =13.60569253 eV and the fine structure constant is e2 1 =7.2973525698 x 10-3 c 137.036 The Bohr radius is given by 2 aB 2 = 0.5291772109217 Å mee The velocity of the electron in the n-th state: e2 e2 c c 1 c vn n c n n n 137.036 3 n: principal quantum number l: Azimuthal quantum number m: magnetic quantum number e2 ((Note)) Fine structure constant (= ) c In physics, the fine-structure constant, also known as Sommerfeld's constant, commonly denoted α (the Greek letter alpha), is a fundamental physical constant characterizing the strength of the electromagnetic interaction between elementary charged particles. It is related to the elementary charge (the electromagnetic coupling constant) e, which characterizes the strength of the coupling of an elementary charged particle with the electromagnetic field, by the formula 2 (=e /(c ) ). Being a dimensionless quantity, it has the same numerical value in all systems of units. Arnold Sommerfeld introduced the fine-structure constant in 1916. https://en.wikipedia.org/wiki/Fine-structure_constant 2. Hydrogen fine structure The Schrödinger solution gives a very good description of the hydrogen atom. The motion of electrons is treated as a non-relativistic particle. In reality it is not. There are corrections to these values of the energy. From the Dirac’s relativistic electron theory, the approximation of the Hamiltonian can be derived as follows. 1 p4 e e 2 H p2 e σ (E p) E , 2 2 2 2 2 2 2me 8me c 4me c 8me c where e>0. (i) Third term: relativistic correction p2 m 2c4 p2c2 m c2 m c2 1 m c2 e e e 2 2 e me c p2 1 p4 m c2 [1 ...] m c2 e 2 2 4 4 e 2me c 8 me c p2 1 p4 ... 3 2 2me 8 me c (ii) The fourth term (Thomas correction): spin-orbit interaction 4 e Thomas term = . 2 2 σ (E p) 4me c For a central potential e2 1 e(r) V (r) , or (r) V (r) , r e where is the scalar potential, -e is the charge of electron (e>0 here). 1 1 dV 1 dV E V (r) e r , e e dr r er dr 1 dV 1 dV E p (r p) L , er dr er dr where L is an orbital angular momentum. Then the Thomas term is rewritten as e e 1 dV 2 2 σ (E p) 2 2 ( )σ L 4me c 4me c er dr 1 1 dV 2 2 S L 2me c r dr e2 1 2 2 3 S L 2me c r (Spin-orbit interaction) The spin angular momentum is defined by S σ , 2 which is an automatic consequence of the Dirac theory. (iii) The last term is called the Darwin term. The Darwin term changes the effective potential at the nucleus. It can be interpreted as a smearing out of the electrostatic interaction between the electron and nucleus due to zitterbewegung, or rapid quantum oscillation, of the electron. Sir Charles Galton Darwin (18 December 1887 – 31 December 1962) was an English physicist, the grandson of Charles Darwin. 5 e 2 The Darwin term = E 2 2 8me c For a hydrogen atom, 1 1 E 2V e2 4e (r) . e r It gives rise to an energy shift (the diagonal matrix element) 2 2 2 2 e 2 e 2 4 (r) (r) dr (r) (r) dr 2 2 nlm 2 2 nlm 8me c 2me c which is non-vanishing only for the s state. ______________________________________________________________________________ 3. Relativistic correction According to special relativity, the kinetic energy of an electron of mass m and velocity v is: p2 p4 K 2m 3 2 e 8me c . The first term is the standard non-relativistic expression for kinetic energy. The second term is the lowest-order relativistic correction to this energy. We apply the perturbation theory for this system. pˆ 2 e2 pˆ 4 Hˆ Hˆ Hˆ ( ) 0 R 2m rˆ 3 2 e 8me c where ˆ (0) H0 nlm En nlm , and 6 pˆ 2 e2 pˆ 4 Hˆ Hˆ 0 2m rˆ R 3 2 e , 8me c Noting that 2 2 ˆ e pˆ 2me (H 0 ) rˆ we calculate the matrix element e2 e2 nlm pˆ 4 nlm 4m 2 nlm (Hˆ )(Hˆ ) nlm e 0 rˆ 0 rˆ 2 2 (0) 2 (0) 1 4 1 4me [En 2e En e 2 ] r av r av ((Comment)) A. Das, Lectures on Quantum Mechanics 2nd edition (World Scientific, 2003) As a result, even though the energy levels are degenerate, we can still apply non-degenerate perturbation theory, since the potentially dangerous terms are zero because the numerator vanishes. Then we have the first order correction to the energy eigenvalue 1 ˆ ˆ 4 nlm H R nlm 3 2 nlm p nlm 8me c 1 (0) 2 (0) 1 1 2 4 2 [En 2e En e 2 ] 2mec r av r av Here we use 1 1 2 r av n aB , 7 1 1 2 r 3 2 1 av n a (l ) B 2 and 2 (0) 1 2 En mec 2 , 2 n where 2 2 e aB 2 (Bohr radius), (fine structure constant). mee c Then we find that (1) ˆ En nlm H rel nlm 1 1 3 m c2 4[ ] 2 e n3 (l 1/ 2) 4n4 m c2 4 1 3 e ( ) 2n3 l 1/ 2 4n 2 4 mec 4n 4 ( 3) 8n l 1/ 2 (0) 2 En 4n 2 ( 3) 2mec l 1/ 2 1 1 3 2E (0) ( ) n 1 n l 4n 2 where 4 2 (0) 2 1 2 4 (0) 1 2 En me c . En mec 4 n4 2 n 2 (1) ((Calculation of En )) Hydrogen 8 (1) En 1s (l = 0) -7.30456 cm-1 ________________________________________ 2s (l = 0) -1.18699 cm-1 2p (l = 1) -0.21305 cm-1 ________________________________________ 3s (l = 0) -0.378755 cm-1 3p (l = 1) -0.0901798 cm-1 3d (l = 2) -0.0324647 ________________________________________ 4s (l = 0) -0,165494 cm-1 4p (l = 1) -0.0437513 cm-1 4d (l = 2) -0.094027 cm-1 4f (l = 3) -0.00896766 cm-1 ((Note)) Commutation relations 4 ˆ pˆ H R 3 2 8me c We note that 2 ˆ 2 ˆ 2 ˆ [ pˆ , Lx ] [ pˆ , Ly ] [ pˆ , Lz ] 0 [ pˆ 2 , Lˆ2 ] 0 2 ˆ pˆ since the Hamiltonian of free particle H free is invariant under the rotation of the system, 2me Then we have ˆ ˆ ˆ ˆ ˆ ˆ [H free , Lx ] [H free , Ly ] [H free , Lz ] 0 . 9 ˆ ˆ2 [H free , L ] 0 These relations lead to the commutation relations 4 ˆ2 4 ˆ [ pˆ , L ] 0 , [ pˆ , Lz ] 0 since [ pˆ 4 , Lˆ2 ] pˆ 2[ pˆ 2 , Lˆ2 ] [ pˆ 2 , Lˆ2 ]pˆ 2 0 4 ˆ 2 2 ˆ 2 ˆ 2 [ pˆ , Lz ] pˆ [ pˆ , Lz ] [ pˆ , Lz ]pˆ 0 Thus we have ˆ ˆ2 ˆ ˆ [H R , L ] 0 , [HR ,Lz ] 0 Since ˆ ˆ2 ˆ ˆ [H0, L ] 0 , [H 0 , Lz ] 0 with pˆ 2 e2 Hˆ 0 2m rˆ e We note that ˆ ˆ2 ˆ ˆ [H, L ] 0 , [H, Lz ] 0 but ˆ ˆ [H R , H ] 0 ((Perturbation theory-non-degenerate case)) 10 ˆ ˆ2 ˆ is a simultaneous eigenket of H, L , and Lz ; ˆ ˆ2 2 ˆ H E , L l(l 1) , Lz m We apply the perturbation theory for the non-degenerate case; ˆ ˆ (0) (1) (0) (1) (0) (1) (H0 H R )( n n ...) (En En ...)( n n ...) with (0) n nlm 0-th order ˆ (0) (0) (0) H0 n En n -th order ˆ (0) ˆ (1) (0) (1) (1) (0) H R n H0 n En n En n (0) Multiplying n from the left-side of this equation (0) ˆ (0) (0) ˆ (1) (0) (0) (1) (1) n H R n n H 0 n En n n En or (1) (0) ˆ (0) En n H R n ˆ nlm H R nlm 1 1 3 E (0)[1 2 ( ) n 1 n l 4n 2 The energy depends on both n and l.
Load more

Recommended publications
  • Charles Hard Townes (1915–2015)
    ARTICLE-IN-A-BOX Charles Hard Townes (1915–2015) C H Townes shared the Nobel Prize in 1964 for the concept of the laser and the earlier realization of the concept at microwave frequencies, called the maser. He passed away in January of this year, six months short of his hundredth birthday. A cursory look at the archives shows a paper as late as 2011 – ‘The Dust Distribution Immediately Surrounding V Hydrae’, a contribution to infrared astronomy. To get a feel for the range in time and field, his 1936 masters thesis was based on repairing a non-functional van de Graaf accelerator at Duke University in 1936! For his PhD at the California Institute of Technology, he measured the spin of the nucleus of carbon-13 using isotope separation and high resolution spectroscopy. Smythe, his thesis supervisor was writing a comprehensive text on electromagnetism, and Townes solved every problem in it – it must have stood him in good stead in what followed. In 1939, even a star student like him did not get an academic job. The industrial job he took set him on his lifetime course. This was at the legendary Bell Telephone Laboratories, the research wing of AT&T, the company which set up and ran the first – and then the best – telephone system in the world. He was initially given a lot of freedom to work with different research groups. During the Second World War, he worked in a group developing a radar based system for guiding bombs. But his goal was always physics research. After the War, Bell Labs, somewhat reluctantly, let him pursue microwave spectroscopy, on the basis of a technical report he wrote suggesting that molecules might serve as circuit elements at high frequencies which were important for communication.
    [Show full text]
  • Wolfgang Pauli Niels Bohr Paul Dirac Max Planck Richard Feynman
    Wolfgang Pauli Niels Bohr Paul Dirac Max Planck Richard Feynman Louis de Broglie Norman Ramsey Willis Lamb Otto Stern Werner Heisenberg Walther Gerlach Ernest Rutherford Satyendranath Bose Max Born Erwin Schrödinger Eugene Wigner Arnold Sommerfeld Julian Schwinger David Bohm Enrico Fermi Albert Einstein Where discovery meets practice Center for Integrated Quantum Science and Technology IQ ST in Baden-Württemberg . Introduction “But I do not wish to be forced into abandoning strict These two quotes by Albert Einstein not only express his well­ more securely, develop new types of computer or construct highly causality without having defended it quite differently known aversion to quantum theory, they also come from two quite accurate measuring equipment. than I have so far. The idea that an electron exposed to a different periods of his life. The first is from a letter dated 19 April Thus quantum theory extends beyond the field of physics into other 1924 to Max Born regarding the latter’s statistical interpretation of areas, e.g. mathematics, engineering, chemistry, and even biology. beam freely chooses the moment and direction in which quantum mechanics. The second is from Einstein’s last lecture as Let us look at a few examples which illustrate this. The field of crypt­ it wants to move is unbearable to me. If that is the case, part of a series of classes by the American physicist John Archibald ography uses number theory, which constitutes a subdiscipline of then I would rather be a cobbler or a casino employee Wheeler in 1954 at Princeton. pure mathematics. Producing a quantum computer with new types than a physicist.” The realization that, in the quantum world, objects only exist when of gates on the basis of the superposition principle from quantum they are measured – and this is what is behind the moon/mouse mechanics requires the involvement of engineering.
    [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]
  • Physics Nobel 1997 Carl E. Wieman
    Julius Pluecker KLEIN TREE #1 c Dr. John Andraos, 2002 (Marburg, 1824) Klein bottle Carl L.F. Lindemann Max Born Richard Bornstein (Erlangen, 1873) (Goettingen, 1907) (Goettingen, 1872) proof that pi is transcendental (1882) Physics Nobel 1954 Sommerfeld model of the atom (1916) Hund's rules Born-Haber cycle (1919) Maria Goeppert-Mayer Born-Oppenheimer Victor Weisskopf (1925) Bigeleisen-Goeppert-Mayer (Goettingen, 1931) approximation (1927) heavy atom approximation (1947) discoveries relating to nuclear shell structure (1949) Max L.H. Delbrueck Physics Nobel 1963 Discoveries concerning Willis Eugene Lamb, Jr. Julian Schwinger Nicholas Kemmer Wendell H. Furry Murray Gell-Mann (ETH-Zurich, 1935) replication mechanism and (Illinois, 1932) Fine structure of H spectrum (Columbia, 1939; UC Berkeley) genetic material of viruses Physics Nobel 1955 Physics Nobel 1965 classification of elementary particles and their interactions Physiology & Medicine Moller-Plesset Abdus Salam Nobel 1969 eight-fold way, (1961), quark Jones effect single point calculation (1964) Physics Nobel 1969 Theory of unified weak (1948) (1934) Walter Kohn Sheldon L. Glashow and electromagnetic Development of DFT theory of unified weak Kenneth G. Wilson interaction between Chemistry Nobel 1998 and electromagnetic theory of critical phenomena elementary particles; Isidor I. Rabi Benjamin Mottelson forces between elementary in connection with phase weak neutral current (Columbia, 1927; Munich) Aage Bohr particles; prediction of transitions Physics Nobel 1979 Physics Nobel 1944 theory of structure of atomic weak neutral current Physics Nobel 1982 Physics Nobel 1979 Walter Gilbert nucleus Physics Nobel 1975 Maxam-Gilbert sequencing method Bernard T. Feld Norman F. Ramsey Martin L. Perl Julian Schwinger (1977) (Columbia, 1945) (Columbia, 1940) (Columbia, 1955) (Columbia, 1939) David J.
    [Show full text]
  • Turning Point in the Development of Quantum Mechanics and the Early Years of the Mossbauer Effect*
    Fermi National Accelerator Laboratory FERMILAB-Conf-76/87-THY October 1976 A TURNING POINT IN THE DEVELOPMENT OF QUANTUM MECHANICS AND THE EARLY YEARS OF THE MOSSBAUER EFFECT* Harry J. Lipkin' Weizmann Institute of Science, Rehovot, Israel Argonne National Laboratory, Argonne, Illinois 60^39 Fermi National Accelerator Laboratory"; Batavia, Illinois 60S10 It is interesting to hear about the exciting early days recalled by Professors Wigner and Wick. I learned quantum theory at a later period, which might be called a turning point in its development, when the general attitude toward quantum mechanics and the study of physics was very different from what it is today. As an undergraduate student in electrical engineering in 19^0 in the United States I found a certain disagreement between the faculty and the students about the "relevance'- of the curriculum. Students thought a k-year course in electrical engineering should include more electronics than a one-semester 3-hour course. But the establishment emphasized the study of power machinery and power transmission because 95'/° of their graduates would eventually get jobs in power. Electronics, they said, was fun for students who were radio hams but useless on the job market. Students at that time did not have today's attitudes and did not stage massive demonstrations and protests against the curriculum. Instead a few of us who wished to learn more interesting things satisfied all the requirements of the engineering school and spent as much extra time as possible listening to fascinating courses in the physics building. There we had the opportunity to listen to two recently-arrived Europeans, Bruno Rossi and Hans Bethe.
    [Show full text]
  • Laser Spectroscopy to Resolve Hyperfine Structure of Rubidium
    Laser spectroscopy to resolve hyperfine structure of rubidium Hannah Saddler, Adam Egbert, and Will Weigand (Dated: 12 November 2015) This experiment had two main goals: to create an absorption spectrum for rubidium using the technique of absorption spectroscopy and to resolve the hyperfine structures for the two rubidium isotopes using saturation absorption spectroscopy. The absorption spectrum was used to determine the frequency difference between the ground state and first excited state for both isotopes. The calculated frequency difference was 6950 MHz ± 90 MHz for rubidium 87 and 3060 MHz ± 60 MHz for rubidium 85. Both values agree with the literature values. The hyperfine structure for rubidium 87 was able to be resolved using this experimental setup. The energy differences were determined to be 260 MHz ± 10 MHz and 150 MHz ± 10 Mhz MHz. The hyperfine structure for rubidium 85 was unable to be resolved using this experimental setup. Additionally the theory of doppler broadening was used to make measurements of the full width half maximum. These values were used to calculate a temperature of 310K ± 40 K which makes sense because the experiments were performed at room temperature. I. INTRODUCTION in the theory section and how they were manipulated and used to derive the results from the recorded data. Addi- tionally there is an explanation of experimental error and The era of modern spectroscopy began with the in- uncertainty associated the results. Section V is a conclu- vention of the laser. The word laser was originally an sion that ties the results of the experiment we performed acronym that stood for light amplification by stimulated to the usefulness of the technique of laser spectroscopy.
    [Show full text]
  • Laser Spectroscopy Experiments
    Hyperfine Spectrum of Rubidium: laser spectroscopy experiments Physics 480W (Dated: Sp19 Paper #4) I. OBJECTIVES FOR THESE EXPERIMENTS We wish to use the technique of absorption spec- troscopy to probe and detect the energy level structure of atomic Rubidium, Rb I, whose ground state is split by a tiny amount on account of nuclear magnetism. In effect, the spectroscopy we do today tells us about nuclear prop- erties and so combines atomic and nuclear physics. The main result of this experiment, the 4th of the semester, is to 1. measure the hyperfine splitting for each isotope, and compare with accepted values, with the fol- lowing details in mind: (a) what is the hyperfine splitting of the ground 2 state, S1=2 term? Do we need saturation- absorption techniques for this? (b) what are the hyperfine splittings of the ex- 2 cited state, P3=2 term, that can be reached with a nominal wavelength of 780nm from the ground state? Here we need saturation- absorption techniques to perform sub-Doppler FIG. 1. Note the four 'blobs'. Why are there four? Which spectroscopy, certainly. Help the reader un- 85 are associated with Rb37, and so on. If all goes swimm- derstand what is entailed in the technique, ingly, we'll get an absorption spectrum that looks much line both experimentally and theoretically. You the figure below the setup. The etalon data will be needed to will need to explain what `saturation' means. make the abscissa something proportional to frequency. The The saturation intensity is an important fig- accepted value of the gap between the 2 outermost dips is ure of merit.
    [Show full text]
  • The Concept of the Photon—Revisited
    The concept of the photon—revisited Ashok Muthukrishnan,1 Marlan O. Scully,1,2 and M. Suhail Zubairy1,3 1Institute for Quantum Studies and Department of Physics, Texas A&M University, College Station, TX 77843 2Departments of Chemistry and Aerospace and Mechanical Engineering, Princeton University, Princeton, NJ 08544 3Department of Electronics, Quaid-i-Azam University, Islamabad, Pakistan The photon concept is one of the most debated issues in the history of physical science. Some thirty years ago, we published an article in Physics Today entitled “The Concept of the Photon,”1 in which we described the “photon” as a classical electromagnetic field plus the fluctuations associated with the vacuum. However, subsequent developments required us to envision the photon as an intrinsically quantum mechanical entity, whose basic physics is much deeper than can be explained by the simple ‘classical wave plus vacuum fluctuations’ picture. These ideas and the extensions of our conceptual understanding are discussed in detail in our recent quantum optics book.2 In this article we revisit the photon concept based on examples from these sources and more. © 2003 Optical Society of America OCIS codes: 270.0270, 260.0260. he “photon” is a quintessentially twentieth-century con- on are vacuum fluctuations (as in our earlier article1), and as- Tcept, intimately tied to the birth of quantum mechanics pects of many-particle correlations (as in our recent book2). and quantum electrodynamics. However, the root of the idea Examples of the first are spontaneous emission, Lamb shift, may be said to be much older, as old as the historical debate and the scattering of atoms off the vacuum field at the en- on the nature of light itself – whether it is a wave or a particle trance to a micromaser.
    [Show full text]
  • Polykarp Kusch 1 9 1 1 — 1 9 9 3
    NATIONAL ACADEMY OF SCIENCES POLYKARP KUSCH 1 9 1 1 — 1 9 9 3 A Biographical Memoir by NORMAN F. RAMSEY Any opinions expressed in this memoir are those of the author and do not necessarily reflect the views of the National Academy of Sciences. Biographical Memoir COPYRIGHT 2008 NATIONAL ACADEMY OF SCIENCES WASHINGTON, D.C. POLYKARP KUSCH January 26, 1911–March 20, 1993 BY NORMAN F . RAMSEY OLYKARP KUSCH, A GREAT physicist, teacher, and Nobel laure- Pate, died in Dallas, Texas, at age 82 on March 20, 1993. Kusch was a pioneer in molecular beam magnetic resonance experiments; he and his associates, with unprecedented high accuracy, measured many atomic and nuclear spins, magnetic dipole moments, electric quadrupole moments, and atomic hyperfine structure separations. Kusch and his associates also made the first direct measurement of the magnetic moment of the electron, which showed that it was consistent with the previously observed anomalous hyperfine separation in atomic hydrogen and with J. Schwinger’s then-new relativistic quantum electrodynamics (QED). Polykarp Kusch was born in Blankenburg, Germany, on January 26, 1911, the son of John Mathias Kusch, a Lutheran missionary, and Henrietta van der Haas. The family emigrated to the United States in 1912, and Kusch became a naturalized U.S. citizen in 1922. He attended grade school in the Mid- west, and started his college education as a chemistry major at Case Institute of Technology in Cleveland, Ohio, shifting to physics before receiving his bachelor of science degree in 1931. He then moved to the University of Illinois, where in 1933 he received an M.S.
    [Show full text]
  • Advanced Information on the Nobel Prize in Physics, 5 October 2004
    Advanced information on the Nobel Prize in Physics, 5 October 2004 Information Department, P.O. Box 50005, SE-104 05 Stockholm, Sweden Phone: +46 8 673 95 00, Fax: +46 8 15 56 70, E-mail: [email protected], Website: www.kva.se Asymptotic Freedom and Quantum ChromoDynamics: the Key to the Understanding of the Strong Nuclear Forces The Basic Forces in Nature We know of two fundamental forces on the macroscopic scale that we experience in daily life: the gravitational force that binds our solar system together and keeps us on earth, and the electromagnetic force between electrically charged objects. Both are mediated over a distance and the force is proportional to the inverse square of the distance between the objects. Isaac Newton described the gravitational force in his Principia in 1687, and in 1915 Albert Einstein (Nobel Prize, 1921 for the photoelectric effect) presented his General Theory of Relativity for the gravitational force, which generalized Newton’s theory. Einstein’s theory is perhaps the greatest achievement in the history of science and the most celebrated one. The laws for the electromagnetic force were formulated by James Clark Maxwell in 1873, also a great leap forward in human endeavour. With the advent of quantum mechanics in the first decades of the 20th century it was realized that the electromagnetic field, including light, is quantized and can be seen as a stream of particles, photons. In this picture, the electromagnetic force can be thought of as a bombardment of photons, as when one object is thrown to another to transmit a force.
    [Show full text]
  • From the Executive Director Kathryn Sullivan to Receive Sigma Xi's Mcgovern Award
    May-June 2011 · Volume 20, Number 3 Kathryn Sullivan to From the Executive Director Receive Sigma Xi’s McGovern Award Annual Report In my report last year I challenged the membership to consider ormer astronaut the characteristics of successful associations. I suggested that we Kathryn D. emulate what successful associations do that others do not. This FSullivan, the first year as I reflect back on the previous fiscal year, I suggest that we need to go even further. U.S. woman to walk We have intangible assets that could, if converted to tangible outcomes, add to the in space, will receive value of active membership in Sigma Xi. I believe that standing up for high ethical Sigma Xi’s 2011 John standards, encouraging the earlier career scientist and networking with colleagues of diverse disciplines is still very relevant to our professional lives. Membership in Sigma P. McGovern Science Xi still represents recognition for scientific achievements, but the value comes from and Society Award. sharing with companions in zealous research. Since 1984, a highlight of Sigma Xi’s Stronger retention of members through better local programs would benefit the annual meeting has been the McGovern Society in many ways. It appears that we have continued to initiate new members in Lecture, which is made by the recipient of numbers similar to past years but retention has declined significantly. In addition, the the McGovern Medal. Recent recipients source of the new members is moving more and more to the “At-large” category and less and less through the Research/Doctoral chapters. have included oceanographer Sylvia Earle and Nobel laureates Norman Borlaug, Mario While Sigma Xi calls itself a “chapter-based” Society, we have found that only about half of our “active” members are affiliated with chapters in “good standing.” As long Molina and Roald Hoffmann.
    [Show full text]
  • By Willis Lamb
    FIVE ENCOUNTERS WITH FELIX BLOCH by Willis Lamb ABSTRACT The impact of Felix Bloch's work on the fields of parity non- conservation, the Mossbauer effect, nuclear induction, chemical shifts, and laser theory is described from a personal point of view. I have benefited enormously from contacts with a number of the great theoretical physicists of the twentieth century. One such relationship far exceeds all the others in respect to duration and meaning to me. I am going to describe five encounters with Felix Bloch that involved purely scientific matters. Personal matters come into the account only to set the times and places of the episodes related. The first two and the last of the five en- counters involved suggestions Felix made to me in connection with my re- search. If I had had the wit, energy, and luck to folIow up properly the earli- est two of these leads, I might have made some very good discoveries. The third encounter involved a request from him for help on his research. It turned out that he did not, after the fact, need this help. Still, the story has a certain interest for me and might provide a footnote for a history of modern physics. The fourth encounter was very slight. I had worked on a certain prob- lem in the early forties. Bloch was working in the same area in the earIy fifties. I had missed following up some interesting aspects of my work. %loch and I talked about his problem and its relationship to my earlier re- search. It later turned out that his work was capable of enormous applica- tion, in chemistry rather than in physics, so that he did not follow it up as far as he might have done.
    [Show full text]