Chem 103, Section F0F Lecture 6
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
Hendrik Antoon Lorentz's Struggle with Quantum Theory A. J
Hendrik Antoon Lorentz’s struggle with quantum theory A. J. Kox Archive for History of Exact Sciences ISSN 0003-9519 Volume 67 Number 2 Arch. Hist. Exact Sci. (2013) 67:149-170 DOI 10.1007/s00407-012-0107-8 1 23 Your article is published under the Creative Commons Attribution license which allows users to read, copy, distribute and make derivative works, as long as the author of the original work is cited. You may self- archive this article on your own website, an institutional repository or funder’s repository and make it publicly available immediately. 1 23 Arch. Hist. Exact Sci. (2013) 67:149–170 DOI 10.1007/s00407-012-0107-8 Hendrik Antoon Lorentz’s struggle with quantum theory A. J. Kox Received: 15 June 2012 / Published online: 24 July 2012 © The Author(s) 2012. This article is published with open access at Springerlink.com Abstract A historical overview is given of the contributions of Hendrik Antoon Lorentz in quantum theory. Although especially his early work is valuable, the main importance of Lorentz’s work lies in the conceptual clarifications he provided and in his critique of the foundations of quantum theory. 1 Introduction The Dutch physicist Hendrik Antoon Lorentz (1853–1928) is generally viewed as an icon of classical, nineteenth-century physics—indeed, as one of the last masters of that era. Thus, it may come as a bit of a surprise that he also made important contribu- tions to quantum theory, the quintessential non-classical twentieth-century develop- ment in physics. The importance of Lorentz’s work lies not so much in his concrete contributions to the actual physics—although some of his early work was ground- breaking—but rather in the conceptual clarifications he provided and his critique of the foundations and interpretations of the new ideas. -
Wave Nature of Matter: Made Easy (Lesson 3) Matter Behaving As a Wave? Ridiculous!
Wave Nature of Matter: Made Easy (Lesson 3) Matter behaving as a wave? Ridiculous! Compiled by Dr. SuchandraChatterjee Associate Professor Department of Chemistry Surendranath College Remember? I showed you earlier how Einstein (in 1905) showed that the photoelectric effect could be understood if light were thought of as a stream of particles (photons) with energy equal to hν. I got my Nobel prize for that. Louis de Broglie (in 1923) If light can behave both as a wave and a particle, I wonder if a particle can also behave as a wave? Louis de Broglie I’ll try messing around with some of Einstein’s formulae and see what I can come up with. I can imagine a photon of light. If it had a “mass” of mp, then its momentum would be given by p = mpc where c is the speed of light. Now Einstein has a lovely formula that he discovered linking mass with energy (E = mc2) and he also used Planck’s formula E = hf. What if I put them equal to each other? mc2 = hf mc2 = hf So for my photon 2 mp = hfhf/c/c So if p = mpc = hfhf/c/c p = mpc = hf/chf/c Now using the wave equation, c = fλ (f = c/λ) So mpc = hc /λc /λc= h/λ λ = hp So you’re saying that a particle of momentum p has a wavelength equal to Planck’s constant divided by p?! Yes! λ = h/p It will be known as the de Broglie wavelength of the particle Confirmation of de Broglie’s ideas De Broglie didn’t have to wait long for his idea to be shown to be correct. -
Einstein's Mistakes
Einstein’s Mistakes Einstein was the greatest genius of the Twentieth Century, but his discoveries were blighted with mistakes. The Human Failing of Genius. 1 PART 1 An evaluation of the man Here, Einstein grows up, his thinking evolves, and many quotations from him are listed. Albert Einstein (1879-1955) Einstein at 14 Einstein at 26 Einstein at 42 3 Albert Einstein (1879-1955) Einstein at age 61 (1940) 4 Albert Einstein (1879-1955) Born in Ulm, Swabian region of Southern Germany. From a Jewish merchant family. Had a sister Maja. Family rejected Jewish customs. Did not inherit any mathematical talent. Inherited stubbornness, Inherited a roguish sense of humor, An inclination to mysticism, And a habit of grüblen or protracted, agonizing “brooding” over whatever was on its mind. Leading to the thought experiment. 5 Portrait in 1947 – age 68, and his habit of agonizing brooding over whatever was on its mind. He was in Princeton, NJ, USA. 6 Einstein the mystic •“Everyone who is seriously involved in pursuit of science becomes convinced that a spirit is manifest in the laws of the universe, one that is vastly superior to that of man..” •“When I assess a theory, I ask myself, if I was God, would I have arranged the universe that way?” •His roguish sense of humor was always there. •When asked what will be his reactions to observational evidence against the bending of light predicted by his general theory of relativity, he said: •”Then I would feel sorry for the Good Lord. The theory is correct anyway.” 7 Einstein: Mathematics •More quotations from Einstein: •“How it is possible that mathematics, a product of human thought that is independent of experience, fits so excellently the objects of physical reality?” •Questions asked by many people and Einstein: •“Is God a mathematician?” •His conclusion: •“ The Lord is cunning, but not malicious.” 8 Einstein the Stubborn Mystic “What interests me is whether God had any choice in the creation of the world” Some broadcasters expunged the comment from the soundtrack because they thought it was blasphemous. -
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. -
25 Years of Quantum Hall Effect
S´eminaire Poincar´e2 (2004) 1 – 16 S´eminaire Poincar´e 25 Years of Quantum Hall Effect (QHE) A Personal View on the Discovery, Physics and Applications of this Quantum Effect Klaus von Klitzing Max-Planck-Institut f¨ur Festk¨orperforschung Heisenbergstr. 1 D-70569 Stuttgart Germany 1 Historical Aspects The birthday of the quantum Hall effect (QHE) can be fixed very accurately. It was the night of the 4th to the 5th of February 1980 at around 2 a.m. during an experiment at the High Magnetic Field Laboratory in Grenoble. The research topic included the characterization of the electronic transport of silicon field effect transistors. How can one improve the mobility of these devices? Which scattering processes (surface roughness, interface charges, impurities etc.) dominate the motion of the electrons in the very thin layer of only a few nanometers at the interface between silicon and silicon dioxide? For this research, Dr. Dorda (Siemens AG) and Dr. Pepper (Plessey Company) provided specially designed devices (Hall devices) as shown in Fig.1, which allow direct measurements of the resistivity tensor. Figure 1: Typical silicon MOSFET device used for measurements of the xx- and xy-components of the resistivity tensor. For a fixed source-drain current between the contacts S and D, the potential drops between the probes P − P and H − H are directly proportional to the resistivities ρxx and ρxy. A positive gate voltage increases the carrier density below the gate. For the experiments, low temperatures (typically 4.2 K) were used in order to suppress dis- turbing scattering processes originating from electron-phonon interactions. -
CV Klaus Von Klitzing
Curriculum Vitae Professor Dr. Klaus von Klitzing Name: Klaus von Klitzing Born: 28 June 1943 Major Scientific Interests: Solid State Research, Experimental Solid Physics, Low Dimensional Electron Systems, Quantum Hall Effect Nobel Prize in Physics 1985 Academic and Professional Career since 1985 Director at the Max Planck Institute for Solid State Research and Honorary Professor at Stuttgart University, Germany 1980 - 1984 Professor at the Technical University Munich, Germany 1978 Habilitation 1972 Ph.D. in Physics 1969 - 1980 University of Würzburg, Germany 1962 - 1969 Diploma in Physics Technical University Braunschweig, Germany Functions in Scientific Societies and Committees (Selection) 2011 Scientific Advisory Board Graphene Flagship 2008 Scientific Committee Bayer Climate Award Nationale Akademie der Wissenschaften Leopoldina www.leopoldina.org 1 2007 EURAMET Research Council 2006 Board of Trustees “Institute of Advanced Studies” of TUM 2005 Jury Member START-Wittgenstein Program Austria 2005 Scientific Committee International Solvay Institutes 2000 NTT - Basic Research Laboratory Advisory Board 1992 Bord of Trustees of the German Museum Munich, Germany 1989 Bord of Trustees of the Physikalisch-Technische Bundesanstalt Braunschweig Honours and Awarded Memberships (Selection) 2019 Member of Orden Pour le Mérite 2012 TUM Distinguished Affiliated Professor 2011 Honorary Degree of the National University of Mongolia 2011 Honorary Degree of the Weizmann Institute of Science, Rehovot 2010 Honorary Member of the Deutsche Hochschulverband -
Essays on Einstein's Science And
MAX-PLANCK-INSTITUT FÜR WISSENSCHAFTSGESCHICHTE Max Planck Institute for the History of Science PREPRINT 63 (1997) Giuseppe Castagnetti, Hubert Goenner, Jürgen Renn, Tilman Sauer, and Britta Scheideler Foundation in Disarray: Essays on Einstein’s Science and Politics in the Berlin Years ISSN 0948-9444 PREFACE This collection of essays is based on a series of talks given at the Boston Colloquium for Philosophy of Science, March 3 – 4, 1997, under the title “Einstein in Berlin: The First Ten Years.“ The meeting was organized by the Center for Philosophy and History of Science at Boston University and the Collected Papers of Albert Einstein, and co-sponsored by the Max Planck Institute for the History of Science. Although the three essays do not directly build upon one another, we have nevertheless decided to present them in a single preprint for two reasons. First, they result from a project that grew out of an earlier cooperation inaugurated by the Berlin Working Group “Albert Einstein.“ This group was part of the research center “Development and Socialization“ under the direction of Wolfgang Edel- stein at the Max Planck Institute for Human Development and Education.1 The Berlin Working Group, directed by Peter Damerow and Jürgen Renn, was sponsored by the Senate of Berlin. Its aim was to pursue research on Einstein in Berlin with particular attention to the relation between his science and its context. The research activities of the Working Group are now being continued at the Max Planck Institute for the History of Science partly, in cooperation with Michel Janssen, John Norton, and John Stachel. -
Max Planck Society's Careful Planning Reaps Benefits
briefing Within the east German research insti- “We were not treated unfairly, according tutes of the Leibniz Society, three-quarters of to western rules,” he says. “But the rules were institute directors, and over a third of depart- ost see the against us. For example, the selection process ment heads, come from west Germany. The West German was in English, whereas we could have done directors of the three new national research M better in Russian, and publication record was centres are west Germans, and 55 per cent of ‘takeover’ as having a major criterion, whereas we had had few department heads are from west Germany chances to publish in western journals.” with a further eight per cent coming from been inevitable There were also cultural differences. “We abroad. all spoke German, yet after 40 years of cultur- Even more extreme ratios exist in the 20 peared for the good of east Germany’s scien- al divide it was hard to really talk to each Max Planck institutes, with only three of the tific future, he says. At his own Institute for other,” says Horst Franz Kern, dean of sci- 240 institute directors and department Plant Biochemistry, from which he retired as ence at the University of Marburg, who heads being east Germans. In contrast to director at the end of 1997, “even those hired chaired the Wissenschaftsrat’s committee on universities and other research organiza- on temporary grant money come increas- biology and medicine at the time of the tions, 40 per cent of these top jobs are occu- ingly from west Germany”. -
Klaus Von Klitzing 1985 NOBEL PRIZE in PHYSICS Yoseph Imry, Tel Aviv (School of Physics and Astronomy, Tel Aviv University)
europhysics BULLETIN OF THE EUROPEAN PHYSICAL SOCIETY news J.A. Volume 16 Number 11/12 November/December 1985 Klaus von Klitzing 1985 NOBEL PRIZE IN PHYSICS Yoseph Imry, Tel Aviv (School of Physics and Astronomy, Tel Aviv University) An October 16, 1985, the Swedish meanwhile been surpassed by an order Academy of Sciences announced the of magnitude and the result was found award of the 1985 Nobel Prize in Physics to be universal — independent of mate to Klaus von Klitzing of the Max-Planck rial and sample properties. The plateaux Institute in Stuttgart, for the discovery were also observed by Kawaji and of the Quantized Hall Effect (QHE). The Wakabayashi 2). QHE was reported in 1980 in a paper1) Besides its sheer beauty, this striking by von Klitzing in collaboration with G. result touches upon several topics of Dorda of Siemens and M. Pepper of fundamental interest, has important ap Cambridge. As shown in Fig. 1, the Hall plications to precision measurements Klaus von Klitzing now aged 42 began his conductance Gxy of a 2D electron gas in and metrology, has motivated and will physics studies at the Technical University an MOS was found, for finite ranges of undoubtedly lead to novel develop in Braunschweig and then in 1972 moved to the gate voltage in which the regular ments. Moreover, it relies on the physics the University of Wurzburg gaining his Habi conductance, Gxx, was severely reduc of devices of great industrial interest 3). litation in 1978 after spending a period at the ed, to be quantized with plateaux having Before explaining the effect briefly University of Oxford. -
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. -
Theory and Experiment in the Quantum-Relativity Revolution
Theory and Experiment in the Quantum-Relativity Revolution expanded version of lecture presented at American Physical Society meeting, 2/14/10 (Abraham Pais History of Physics Prize for 2009) by Stephen G. Brush* Abstract Does new scientific knowledge come from theory (whose predictions are confirmed by experiment) or from experiment (whose results are explained by theory)? Either can happen, depending on whether theory is ahead of experiment or experiment is ahead of theory at a particular time. In the first case, new theoretical hypotheses are made and their predictions are tested by experiments. But even when the predictions are successful, we can’t be sure that some other hypothesis might not have produced the same prediction. In the second case, as in a detective story, there are already enough facts, but several theories have failed to explain them. When a new hypothesis plausibly explains all of the facts, it may be quickly accepted before any further experiments are done. In the quantum-relativity revolution there are examples of both situations. Because of the two-stage development of both relativity (“special,” then “general”) and quantum theory (“old,” then “quantum mechanics”) in the period 1905-1930, we can make a double comparison of acceptance by prediction and by explanation. A curious anti- symmetry is revealed and discussed. _____________ *Distinguished University Professor (Emeritus) of the History of Science, University of Maryland. Home address: 108 Meadowlark Terrace, Glen Mills, PA 19342. Comments welcome. 1 “Science walks forward on two feet, namely theory and experiment. ... Sometimes it is only one foot which is put forward first, sometimes the other, but continuous progress is only made by the use of both – by theorizing and then testing, or by finding new relations in the process of experimenting and then bringing the theoretical foot up and pushing it on beyond, and so on in unending alterations.” Robert A. -
The Search for the Gentle Tremble
Flashback_Gravitational Waves The Search for the Gentle Tremble Gravitational waves are some of the most spectacular predictions of the 1915 general theory of relativity. However, it wasn’t until half a century later that physicist Joseph Weber attempted to track them down. In the early 1970s, Max Planck scientists also began working in this research field, and developed second-generation detectors. The groundwork laid by these pioneers meant the waves in space-time ceased to be just figments of the imagination: in September 2015 they were finally detected. TEXT HELMUT HORNUNG Albert Einstein is beset by doubt: it will never be possible to de- of relativity ultimately benefits gravitational waves, too, which tect gravitational waves – the tremble in space-time is simply too strike a chord with at least one physicist: Joseph Weber. weak! Yet it was he himself who had postulated their existence, Born in 1919 in New Jersey, the researcher at the University of which follows from the general theory of relativity he put forward Maryland has an idea for a simple experiment: he suspends an in- in November 1915. A short time later, in 1916 and again in 1918, he credibly heavy aluminum cylinder – 1.5 meters long and 60 centi- devotes a paper to this phenomenon. meters across – in a steel wire loop and attaches piezo sensors to Two decades later, he suddenly has a change of heart: “I have its middle to register oscillations. The whole test rig is housed in been working with a young colleague [Nathan Rosen] and we have a vacuum chamber.