Xxth Century Physics
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Von Richthofen, Einstein and the AGA Estimating Achievement from Fame
Von Richthofen, Einstein and the AGA Estimating achievement from fame Every schoolboy has heard of Einstein; fewer have heard of Antoine Becquerel; almost nobody has heard of Nils Dalén. Yet they all won Nobel Prizes for Physics. Can we gauge a scientist’s achievements by his or her fame? If so, how? And how do fighter pilots help? Mikhail Simkin and Vwani Roychowdhury look for the linkages. “It was a famous victory.” We instinctively rank the had published. However, in 2001–2002 popular French achievements of great men and women by how famous TV presenters Igor and Grichka Bogdanoff published they are. But is instinct enough? And how exactly does a great man’s fame relate to the greatness of his achieve- ment? Some achievements are easy to quantify. Such is the case with fighter pilots of the First World War. Their achievements can be easily measured and ranked, in terms of their victories – the number of enemy planes they shot down. These aces achieved varying degrees of fame, which have lasted down to the internet age. A few years ago we compared1 the fame of First World War fighter pilot aces (measured in Google hits) with their achievement (measured in victories); and we found that We can estimate fame grows exponentially with achievement. fame from Google; Is the same true in other areas of excellence? Bagrow et al. have studied the relationship between can this tell us 2 achievement and fame for physicists . The relationship Manfred von Richthofen (in cockpit) with members of his so- about actual they found was linear. -
A Brief History of Nuclear Astrophysics
A BRIEF HISTORY OF NUCLEAR ASTROPHYSICS PART I THE ENERGY OF THE SUN AND STARS Nikos Prantzos Institut d’Astrophysique de Paris Stellar Origin of Energy the Elements Nuclear Astrophysics Astronomy Nuclear Physics Thermodynamics: the energy of the Sun and the age of the Earth 1847 : Robert Julius von Mayer Sun heated by fall of meteors 1854 : Hermann von Helmholtz Gravitational energy of Kant’s contracting protosolar nebula of gas and dust turns into kinetic energy Timescale ~ EGrav/LSun ~ 30 My 1850s : William Thompson (Lord Kelvin) Sun heated at formation from meteorite fall, now « an incadescent liquid mass » cooling Age 10 – 100 My 1859: Charles Darwin Origin of species : Rate of erosion of the Weald valley is 1 inch/century or 22 miles wild (X 1100 feet high) in 300 My Such large Earth ages also required by geologists, like Charles Lyell A gaseous, contracting and heating Sun 푀⊙ Mean solar density : ~1.35 g/cc Sun liquid Incompressible = 4 3 푅 3 ⊙ 1870s: J. Homer Lane ; 1880s :August Ritter : Sun gaseous Compressible As it shrinks, it releases gravitational energy AND it gets hotter Earth Mayer – Kelvin - Helmholtz Helmholtz - Ritter A gaseous, contracting and heating Sun 푀⊙ Mean solar density : ~1.35 g/cc Sun liquid Incompressible = 4 3 푅 3 ⊙ 1870s: J. Homer Lane ; 1880s :August Ritter : Sun gaseous Compressible As it shrinks, it releases gravitational energy AND it gets hotter Earth Mayer – Kelvin - Helmholtz Helmholtz - Ritter A gaseous, contracting and heating Sun 푀⊙ Mean solar density : ~1.35 g/cc Sun liquid Incompressible = 4 3 푅 3 ⊙ 1870s: J. -
Experiencing Hubble
PRESCOTT ASTRONOMY CLUB PRESENTS EXPERIENCING HUBBLE John Carter August 7, 2019 GET OUT LOOK UP • When Galaxies Collide https://www.youtube.com/watch?v=HP3x7TgvgR8 • How Hubble Images Get Color https://www.youtube.com/watch? time_continue=3&v=WSG0MnmUsEY Experiencing Hubble Sagittarius Star Cloud 1. 12,000 stars 2. ½ percent of full Moon area. 3. Not one star in the image can be seen by the naked eye. 4. Color of star reflects its surface temperature. Eagle Nebula. M 16 1. Messier 16 is a conspicuous region of active star formation, appearing in the constellation Serpens Cauda. This giant cloud of interstellar gas and dust is commonly known as the Eagle Nebula, and has already created a cluster of young stars. The nebula is also referred to the Star Queen Nebula and as IC 4703; the cluster is NGC 6611. With an overall visual magnitude of 6.4, and an apparent diameter of 7', the Eagle Nebula's star cluster is best seen with low power telescopes. The brightest star in the cluster has an apparent magnitude of +8.24, easily visible with good binoculars. A 4" scope reveals about 20 stars in an uneven background of fainter stars and nebulosity; three nebulous concentrations can be glimpsed under good conditions. Under very good conditions, suggestions of dark obscuring matter can be seen to the north of the cluster. In an 8" telescope at low power, M 16 is an impressive object. The nebula extends much farther out, to a diameter of over 30'. It is filled with dark regions and globules, including a peculiar dark column and a luminous rim around the cluster. -
Research Group of the Committee for the Publication of Hantaro Nagaoka's Biography
Research Group of the Committee for the Publication of Hantaro Nagaoka's Biography Eri Yagi* The Research Group, whose members are Dr. Kiyonobu Itakura of the Na tional Institute for Education Research, Mr. Tosaku Kimura of the National Science Museum, and myself, has completed a biography of Hantaro Nagaoka, which will be published soon (in Japanese) by the Asahi Newspaper Publisher in Tokyo. The Research Group was organized by the Committee in 1963. It was just after the special exhibition of Nagaoka's science activities, held at the National Science Museum in Tokyo by the support of the History of Science Society of Japan. The Committee has been directed by Professor Yoshio Fujioka, who had learned physics under Nagaoka. Unpublished materials, e.g., Nagaoka's notebooks, diaries, corespondences, photos were generosly donated to the National Science Museum by the family of Nagaoka. In addition, those who had been in contact with Nagaoka kindly con tributed informations to the Research Group. The above materials and informations have been arranged, cataloged, and examined by the Research Group. Hantaro Nagaoka was bom at Nagasaki prefecture in the southern part of Japan in 1865 and died in Tokyo in 1950. He was primarily responsible for pro moting the advancement of physics in Japan, between 1900 and 1925, as a professor at the Department of Physics, the University of Tokyo. In the earlier period before Nagaoka started his researches, such local studies as the properties of Japanese magic mirrors, earthquakes, and geomagnetism had dominated by the influence of foreign teachers in Japan. In addition to the study of atomic structure, Nagaoka covered varied fields in physics as magnetostriction, geophysics, mathematical physics, spectroscopy, and radio waves. -
Scientific References for Nobel Physics Prizes
1 Scientific References for Nobel Physics Prizes © Dr. John Andraos, 2004 Department of Chemistry, York University 4700 Keele Street, Toronto, ONTARIO M3J 1P3, CANADA For suggestions, corrections, additional information, and comments please send e-mails to [email protected] http://www.chem.yorku.ca/NAMED/ 1901 - Wilhelm Conrad Roentgen "in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him." Roentgen X-ray Roentgen, W.C. Ann. Physik 1898, 64 , 1 Stanton, A. Science 1896, 3 , 227; 726 (translation) 1902 - Hendrik Antoon Lorentz and Pieter Zeeman "in recognition of the extraordinary service they rendered by their researches into the influence of magnetism upon radiation phenomena." Zeeman effect Zeeman, P., Verhandlungen der Physikalischen Gesellschaft zu Berlin 1896, 7 , 128 Zeeman, P., Nature 1897, 55 , 347 (translation by A. Stanton) 1903 - Antoine Henri Becquerel "in recognition of the extraordinary service he has rendered by his discovery of spontaneous radioactivity." Becquerel, A.H. Compt. Rend. 1896, 122 , 420; 501; 559; 689; 1086 Becquerel, A.H. Compt. Rend. 1896, 123 , 855 Becquerel, A.H. Compt. Rend. 1897, 124 , 444; 800 Becquerel, A.H. Compt. Rend. 1899, 129 , 996; 1205 Becquerel, A.H. Compt. Rend. 1900, 130 , 327; 809; 1583 Becquerel, A.H. Compt. Rend. 1900, 131 , 137 Becquerel, A.H. Compt. Rend. 1901, 133 , 977 1903 - Pierre Curie and Marie Curie, nee Sklodowska "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel." Curie unit of radiation Curie, P; Desains, P., Compt. Rend. -
President's Message
Journal of the Northern Sydney Astronomical Society Inc. February 2019 In this issue President’s Message Page 1: President’s message Editorial i everyone. Object of the Month as it had been an idea Page 2: Results of the Photo HWhat a magnificent summer! waiting for someone to bring it to life for Competition It seems ages since the lovely summer days some time. Page 5: Results of the Article have landed on our holiday period in such This past two months’ contributions have Competition a comprehensive way. It has been a great been interesting and seen some wonderful Page 7: The Jupiter/Venus Conjunction holiday period for me and I hope you have images come to life. all had such a great time as I have had. It showcases the skills that some of our The last month’s images and videos I am equally pleased to see the Reflections members have and a big congratulation to of Wirtanen 46P comet, along with magazine has had a resurgence and I Kym Haines, the winner for this month, this month’s incredible photo of M42 encourage everyone to take an interest in Phil Angilley and Daniel Patos, the runner- exemplify the talents that can be found it. ups, for their excellent work. amongst our club members. We are expanding the source of A quick shout out to some upcoming contributions for the magazine with the Kym’s M42 photo as seen on page 2 is events. inclusion of the Object of the Month and magnificent and the colours and framing In April we will be running our New other items of interest to our community. -
The Discovery of Oxygen in the Universe
! ! ! The discovery of oxygen in the Universe The discovery of oxygen! ! Carl Scheele (1742-1786) ! is the first (1773;1777)! to isolate oxygen! Georg Ernst Stahl ! by heating HgO he found ! (1659-1734)! that it released a gas ! the father of the ! which enhanced combustion. ! phlogiston theory. ! ! phlogiston is the fire! Joseph Priestley (1733-1804)! that escapes from matter ! was the first (1774)! when it burns! to publish this result! (which he interpreted within ! the phlogiston theory)! Antoine de Lavoisier (1743-1794) ! discovered that air contains about 20 % oxygen ! and that when any substance burns,! it actually combines chemically with oxygen (1775) ! he gave oxygen its present name (oxy-gen = acid-forming)! he stated the law of the conservation of matter! ! Before the “discovery” of oxygen! Leonardo da Vinci (1452-1519) ! •" air is a mixture of gases! •" breathing ~ combustion! "Where flame cannot live no animal that draw breath can live." ! Michael Sendivogius (1566-1636) ! (Micha" S#dziwój) ! produced a gas he called ! “food of life” ! by heating saltpeter (KNO3) ! ! Cornelius Drebbel (1572-1633)! constructed in 1621 the first submarine . ! To “refresh” the air inside it, he generated oxygen by heating saltpeter as Sendivogius had tought him! “chemistry” before Lavoisier! ! Anaxagoras of Clazomenes (500 BC - 428 BC)! had already expressed “the law of Lavoisier”: ! “Rien ne se perd, rien ne se crée, tout se transforme“! ! ! ! ! Robert Boyle (1627- 1691)! •" noted that it was impossible to combine ! the four Greek elements to form -
Models of the Atom
David Sang Models of the atom Today we are very familiar with the picture of the atom as a particle with a tiny nucleus at its centre and a cloud of electrons orbiting around the nucleus. But where did this model come from? What were scientists trying to explain using their models of the atom? To find out, we have to go back to the early years of the twentieth century. A model of the atom. But does the nucleus glow like this? No. And are electrons blue? No. Discovering radioactivity and the electron By the 1890s, most physicists were convinced that matter was made up of atoms. The idea of vast In this photo, an electron beam is bent along a circular path by a magnetic field. numbers of tiny, moving particles could explain The beam is produced at the bottom in an ‘electron gun’ and follows a clockwise many things, including the behaviour of gases and path inside the evacuated tube. A small amount of gas has been left in the tube; the differences between the chemical elements. this glows to show up the path of the beam. Then, in 1896, Henri Becquerel discovered radioactivity. He was investigating uranium salts, The importance of these two discoveries was that many of which glow in the dark. To his surprise, he they suggested that atoms were not indestructible. Key words Atoms are tiny but they are made of still smaller found that all the uranium-containing substances model that he tested produced invisible radiation that particles. could blacken photographic paper. -
Culturally Inherited Cognitive Activity: Implications for the Rhetoric of Science
University of Windsor Scholarship at UWindsor OSSA Conference Archive OSSA 4 May 17th, 9:00 AM - May 19th, 5:00 PM Culturally Inherited Cognitive Activity: Implications for the Rhetoric of Science Joseph Little Follow this and additional works at: https://scholar.uwindsor.ca/ossaarchive Part of the Philosophy Commons Little, Joseph, "Culturally Inherited Cognitive Activity: Implications for the Rhetoric of Science" (2001). OSSA Conference Archive. 75. https://scholar.uwindsor.ca/ossaarchive/OSSA4/papersandcommentaries/75 This Paper is brought to you for free and open access by the Conferences and Conference Proceedings at Scholarship at UWindsor. It has been accepted for inclusion in OSSA Conference Archive by an authorized conference organizer of Scholarship at UWindsor. For more information, please contact [email protected]. Title: Culturally Inherited Cognitive Activity: Implications for the Rhetoric of Science1 Author: Joseph Little Response to this paper by: Mark Weinstein © 2001 Joseph Little Introduction Few constructs rest more securely upon the foundation of rhetorical theory than the syllogism. Introduced by Aristotle in the fourth century BC, the syllogism provided Athenian orators with structural guidance for constructing valid, deductive arguments in the polis (Aristotle, 1991, 40; Aristotle, 1984a; Aristotle, 1984b). Yet this guidance is not without qualification: Often neglected in modern times is the fact that valid conclusions, for Aristotle, were only expected to follow necessarily from the premises when the audience was comprised of men acting in accordance with orthos logos, or "right reason" (1984c, 1935-36; 1984d, 1766, 1797, 1798, 1808, 1812, 1819). Also neglected in modern times is the fact that Aristotle thought of "right reason" as a developed ability that "comes to us if growth is allowed to proceed regularly" rather than as an innate aspect of human cognition (1984c, 1939-40). -
(Owen Willans) Richardson
O. W. (Owen Willans) Richardson: An Inventory of His Papers at the Harry Ransom Center Descriptive Summary Creator: Richardson, O. W. (Owen Willans), 1879-1959 Title: O. W. (Owen Willans) Richardson Papers Dates: 1898-1958 (bulk 1920-1940) Extent: 112 document boxes, 2 oversize boxes (49.04 linear feet), 1 oversize folder (osf), 5 galley folders (gf) Abstract: The papers of Sir O. W. (Owen Willans) Richardson, the Nobel Prize-winning British physicist who pioneered the field of thermionics, contain research materials and drafts of his writings, correspondence, as well as letters and writings from numerous distinguished fellow scientists. Call Number: MS-3522 Language: Primarily English; some works and correspondence written in French, German, or Italian . Note: The Ransom Center gratefully acknowledges the assistance of the Center for History of Physics, American Institute of Physics, which provided funds to support the processing and cataloging of this collection. Access: Open for research Administrative Information Additional The Richardson Papers were microfilmed and are available on 76 Physical Format reels. Each item has a unique identifying number (W-xxxx, L-xxxx, Available: R-xxxx, or M-xxxx) that corresponds to the microfilm. This number was recorded on the file folders housing the papers and can also be found on catalog slips present with each item. Acquisition: Purchase, 1961 (R43, R44) and Gift, 2005 Processed by: Tessa Klink and Joan Sibley, 2014 Repository: The University of Texas at Austin, Harry Ransom Center Richardson, O. W. (Owen Willans), 1879-1959 MS-3522 2 Richardson, O. W. (Owen Willans), 1879-1959 MS-3522 Biographical Sketch The English physicist Owen Willans Richardson, who pioneered the field of thermionics, was also known for his work on photoelectricity, spectroscopy, ultraviolet and X-ray radiation, the electron theory, and quantum theory. -
The Origin and Evolution of Planetary Nebulae
P1: MRM/SPH P2: MRM/UKS QC: MRM/UKS T1: MRM CB211-FM CB211/Kwok October 30, 1999 1:26 Char Count= 0 THE ORIGIN AND EVOLUTION OF PLANETARY NEBULAE SUN KWOK University of Calgary, Canada iii P1: MRM/SPH P2: MRM/UKS QC: MRM/UKS T1: MRM CB211-FM CB211/Kwok October 30, 1999 1:26 Char Count= 0 PUBLISHED BY THE PRESS SYNDICATE OF THE UNIVERSITY OF CAMBRIDGE The Pitt Building, Trumpington Street, Cambridge, United Kingdom CAMBRIDGE UNIVERSITY PRESS The Edinburgh Building, Cambridge CB2 2RU, UK http://www.cup.cam.ac.uk 40 West 20th Street, New York, NY 10011-4211, USA http://www.cup.org 10 Stamford Road, Oakleigh, Melbourne 3166, Australia Ruiz de Alarc´on 13, 28014 Madrid, Spain c Cambridge University Press 2000 This book is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2000 Printed in the United States of America Typeface Times Roman 10.5/12.5 pt. and Gill Sans System LATEX2ε [TB] A catalog record for this book is available from the British Library. Library of Congress Cataloging in Publication Data Kwok, S. (Sun) The origin and evolution of planetary nebulae / Sun Kwok. p. cm. – (Cambridge astrophysics series : 33) ISBN 0-521-62313-8 (hc.) 1. Planetary nebulae. I. Title. II. Series. QB855.5.K96 1999 523.10135 – dc21 99-21392 CIP ISBN 0 521 62313 8 hardback iv P1: MRM/SPH P2: MRM/UKS QC: MRM/UKS T1: MRM CB211-FM CB211/Kwok October 30, 1999 1:26 Char Count= 0 -
Spin-Or, Actually: Spin and Quantum Statistics
S´eminaire Poincar´eXI (2007) 1 – 50 S´eminaire Poincar´e SPIN OR, ACTUALLY: SPIN AND QUANTUM STATISTICS∗ J¨urg Fr¨ohlich Theoretical Physics ETH Z¨urich and IHES´ † Abstract. The history of the discovery of electron spin and the Pauli principle and the mathematics of spin and quantum statistics are reviewed. Pauli’s theory of the spinning electron and some of its many applications in mathematics and physics are considered in more detail. The role of the fact that the tree-level gyromagnetic factor of the electron has the value ge = 2 in an analysis of stability (and instability) of matter in arbitrary external magnetic fields is highlighted. Radiative corrections and precision measurements of ge are reviewed. The general connection between spin and statistics, the CPT theorem and the theory of braid statistics, relevant in the theory of the quantum Hall effect, are described. “He who is deficient in the art of selection may, by showing nothing but the truth, produce all the effects of the grossest falsehoods. It perpetually happens that one writer tells less truth than another, merely because he tells more ‘truth’.” (T. Macauley, ‘History’, in Essays, Vol. 1, p 387, Sheldon, NY 1860) Dedicated to the memory of M. Fierz, R. Jost, L. Michel and V. Telegdi, teachers, colleagues, friends. arXiv:0801.2724v3 [math-ph] 29 Feb 2008 ∗Notes prepared with efficient help by K. Schnelli and E. Szabo †Louis-Michel visiting professor at IHES´ / email: [email protected] 2 J. Fr¨ohlich S´eminaire Poincar´e Contents 1 Introduction to ‘Spin’ 3 2 The Discovery of Spin and of Pauli’s Exclusion Principle, Historically Speaking 6 2.1 Zeeman, Thomson and others, and the discovery of the electron.......