DOCSLIB.ORG

Interview with H. Victor Neher

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Interview with H. Victor Neher H. VICTOR NEHER (1904 – 1999) INTERVIEWED BY RACHEL PRUD’HOMME April 27 and 28, 1982 H. Victor Neher, 1970 ARCHIVES CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California Subject area Physics Abstract An interview in two sessions, April 27 and 28, 1982, with Henry Victor Neher, professor of physics, emeritus, in the Division of Physics, Mathematics, and Astronomy. Dr. Neher received a BA in physics from Pomona College (1926) and became a graduate student at Caltech in 1928, earning his PhD three years later. In this interview, he recalls his undergraduate years at Pomona, his growing acquaintance with Caltech, and his work as a graduate student on the scattering of high-energy electrons. Recollections of Robert A. Millikan, Earnest Watson, William H. Pickering. He describes Caltech’s cosmic-ray group—Millikan, Carl Anderson, Seth Neddermeyer, Ira S. Bowen—and the plane trips he made throughout North and South America to measure cosmic rays. Recollections of Richard Chace Tolman. Comments on his PhD orals, on teaching undergraduates, on some of his memorable students (Kip Thorne, Howard Berg, H. Guyford Stever). The 100-to-1 Shot Club; John Anderson and Russell Porter. The effect of the Depression on Caltech. War work at the MIT Radiation Laboratory. Changes at Caltech during presidency of Lee Dubridge. Postwar balloon flights http://resolver.caltech.edu/CaltechOH:OH_Neher_H to study cosmic rays. Comments on Frank and J. Robert Oppenheimer and their political difficulties during the McCarthy era. Early campus atmosphere and changes over the years. Donald Glaser and development of the bubble chamber. Administrative information Access The interview is unrestricted. Copyright Copyright has been assigned to the California Institute of Technology © 1982, 2017. All requests for permission to publish or quote from the transcript must be submitted in writing to the University Archivist and Head, Special Collections. Preferred citation Neher, H. Victor. Interview by Rachel Prud’homme. Pasadena, California, April 27 and 28, 1982. Oral History Project, California Institute of Technology Archives. Retrieved [supply date of retrieval] from the World Wide Web: http://resolver.caltech.edu/CaltechOH:OH_Neher_H Contact information Archives, California Institute of Technology Mail Code B215-74 Pasadena, CA 91125 Phone: (626)395-2704 Fax: (626)395-4073 Email: [email protected] Graphics and content © 2017 California Institute of Technology. http://resolver.caltech.edu/CaltechOH:OH_Neher_H CALIFORNIA INSTITUTE OF TECHNOLOGY ARCHIVES ORAL HISTORY PROJECT INTERVIEW WITH H. VICTOR NEHER BY RACHEL PRUD’HOMME WATSONVILLE, CALIFORNIA Copyright © l982, 2017 by the California Institute of Technology http://resolver.caltech.edu/CaltechOH:OH_Neher_H Neher–ii TABLE OF CONTENTS INTERVIEW WITH H. VICTOR NEHER Session 1 1-20 Family background; education; Pomona; introduction to Caltech. Switch from engineering to physics; graduate studies at Caltech; R. C. Tolman. R. A. Millikan as teacher and scholar. Teaching; cosmic-ray research; C. Anderson and S. Neddermeyer. Millikan v. A. H. Compton; Millikan and I. S. Bowen; balloon flights and data collecting of high-altitude cosmic rays. Comments on Bowen and Tolman; orals. Pike’s Peak cosmic-ray experiments. Travel and work with Millikan. Funding for research; Caltech’s ambience. Session 2 21-46 100-to-l Shot Club; R. Porter’s Palomar drawings; Depression’s toll on faculty and research. WW II; MIT’s Radiation Laboratory; microwave receivers. Postwar return to Caltech. Change in Caltech with advent of L. A. DuBridge; students; changes in departmental structures. l947-l948 balloon flights; equipment; graduate students. F. Oppenheimer; J. R. Oppenheimer; McCarthyism. J. R. Oppenheimer as teacher; loss of his security clearance. Vatican conference, 1962. A. Klein and R. Knapp. Social life as a faculty member. Famous visitors to Caltech: Einstein, Lorentz, Sommerfeld. Changes in students over past decades. Interesting students: K. Thorne, H. Berg, G. Stever. Development of courses and equipment in cosmic-ray research; data accuracy. D. Glaser and bubble chamber. Anecdote about G. Holton and Newton quotation. http://resolver.caltech.edu/CaltechOH:OH_Neher_H CALIFORNIA INSTITUTE OF TECHNOLOGY ARCHIVES ORAL HISTORY PROJECT Interview with H. Victor Neher by Rachel Prud’homme Watsonville, California Session 1 April 27, 1982 Session 2 April 28, 1982 Begin Tape 1, Side 1 PRUD’HOMME: Professor Neher, tell me a little bit about yourself. Where were you born and brought up? NEHER: Well, I was born in Kansas. My folks had been back there about four years before I was born, so my older brother and older sister were also born there. We moved back to California when I was nine months old. So I was raised in the San Joaquin Valley, almost due east of Watsonville. I went through grade school in a one-room schoolhouse. We lived in the country. My father was a grain farmer and farmed several thousand acres—mostly barley and some wheat. PRUD’HOMME: And you went to Pomona? NEHER: I went to Pomona College, yes, largely on the recommendation of one of my high school teachers. PRUD’HOMME: What did you study there? NEHER: Well, I thought I was going to be an electrical engineer, so I began taking courses in physics. I took a general course in physics my first year. My teacher was Mr. [George Gale] Hitchcock, who had a Model-T Ford. He would take us over to Caltech for the Friday evening demonstration lectures given in 201 Bridge [Norman Bridge http://resolver.caltech.edu/CaltechOH:OH_Neher_H Neher–2 Laboratory of Physics]. So my first contact with Caltech was in the fall of 1922. There was not much then at Caltech. The east wing of Bridge had been built, and they were in the process of building the west wing. Of course, Throop Hall was there. PRUD’HOMME: What made you decide to go there, as opposed to some other institution? NEHER: Well, I thought it was a good school. And [Robert A.] Millikan [Caltech’s head (chairman of the Executive Council), 1921-1946] impressed me. He gave one of the evening demonstration lectures there that we heard in the fall of 1922. I was very much impressed with his lecture and what he had to say. PRUD’HOMME: Can you remember what the lecture was about? NEHER: Yes. At least part of it was on magnetism. At one stage, he asked a question of the audience: “How does the strength of a magnetic field, like the Earth’s, change with distance?” He looked right at me, so I took it rather personally. [Laughter] My knowledge of physics was rather slim at the time. Anyhow, he used to do this; he would pose questions to the audience. PRUD’HOMME: Is he the one who persuaded you to change to physics from engineering? NEHER: No. I didn’t know him personally all through my Pomona years, although I went over to Pasadena on a good many occasions for the Friday evening lectures. PRUD’HOMME: What was Caltech’s application process then to be a graduate student? Did you have to go through rigorous interviews and tests and so on? NEHER: While I was at Pomona, I got to know some of the people at Caltech. I received my bachelor’s degree from Pomona in 1926. In 1925, there was a new instructor in physics, who had come from Colorado College. His name was [Roland R.] Tileston. He was an extraordinary teacher. He is the one, I suppose, more than anybody else, who got me changed from engineering to physics. He used to load his Dodge up with his students, http://resolver.caltech.edu/CaltechOH:OH_Neher_H Neher–3 and take them over to these Friday evening demonstration lectures and also to other lectures. So I gradually got to know some of the staff at Caltech. One of his students at Colorado College was [William R.] Ralph Smythe, who was, of course, on the faculty at Caltech [professor of physics, emeritus; d.1988]. I knew him early on. Then I stayed on at Pomona for two years after I got my bachelor’s degree, to help out in the physics department; Tileston was expanding the department and needed some help. He was getting in a lot of new equipment for the laboratories and for his lectures and so on. That was a great opportunity. There was an interesting episode in connection with that. During my senior year at Pomona—in fact it was in the early spring of 1926—Tileston had said that Dartmouth would take any student he recommended for graduate work. This was because Tileson had come from Dartmouth, and they were anxious to get graduate students. He wanted me to go to Dartmouth. However, I had already made up my mind to go to Caltech. I was talking with him one day, and he said he had to get somebody to go back to Dartmouth rather soon, because this position would not be open very long. He asked me if I knew anybody who might be interested. Well, my roommate [M. Stanley] Livingston was majoring in chemistry. I thought maybe he might be persuaded to go into physics. So I went over to the chemistry lab and asked him if he wanted to be a physicist instead of a chemist; I told him what the situation was. He came over and talked with Tileston. Tileston gave him twenty-four hours to make up his mind whether he would take this or not. He decided within twenty-four hours that he was going to be a physicist! Livingston later worked with [Ernest O.] Lawrence at UC Berkeley on cyclotrons and ended up at MIT. He became one of the country’s experts on high-energy particle machines. PRUD’HOMME: When you came here as a graduate student, what was the campus like? Where did you live? What did you do with your social life? When you wanted to get away from it all, where did you go? NEHER: Well, I lived up on Del Mar Boulevard.
Load more

Recommended publications
  • People and Things
    sure that it is good for us to search though we could predict how every chaos. And of course it's even for them, in the same way that molecule in a glass of water would more true for sciences outside the Spanish explorers, whey they first behave, nowhere in the mountain area of physics, especially for pushed northward from the central of computer printout would we find sciences like astronomy and biolo­ parts of Mexico, were searching for the properties of water that really gy, for which also an element of the seven golden cities of Cibola. interest us, properties like tempera­ history enters. They didn't find them, but they ture and entropy. These properties I'm also not saying that elemen­ found other useful things, like have to be dealt with in their own tary particle physics is more impor­ Texas. terms, and for this we have the tant than other branches of phys­ Let me also say what I don't science of thermodynamics, which ics. All I'm saying is that, because mean by final, underlying, laws of deals with heat without at every of its concern with underlying laws, physics. I don't mean that other step reducing it to the properties of elementary particle physics has a branches of physics are in danger molecules or elementary particles. special importance of its own, even of being replaced by some ultimate There is no doubt today that, ul­ though it's not necessarily of great version of elementary particle timately, thermodynamics is what it immediate practical value.
    [Show full text]
  • Character List
    Character List - Bomb ​ Use this chart to help you keep track of the hundreds of names of physicists, freedom fighters, government officials, and others involved in the making of the atomic bomb. Scientists Political/Military Leaders Spies Robert Oppenheimer - Winston Churchill -- Prime Klaus Fuchs - physicist in ​ ​ ​ designed atomic bomb. He was Minister of England Manhattan Project who gave accused of spying. secrets to Russia Franklin D. Roosevelt -- ​ Albert Einstein - convinced President of the United States Harry Gold - spy and Courier ​ ​ U.S. government that they for Russia KGB. Narrator of the needed to research fission. Harry Truman -- President of story ​ the United States Enrico Fermi - created first Ruth Werner - Russian spy ​ ​ chain reaction Joseph Stalin -- dictator of the ​ Tell Hall -- physicist in Soviet Union ​ Igor Korchatov -- Russian Manhattan Project who gave ​ physicist in charge of designing Adolf Hitler -- dictator of secrets to Russia ​ bomb Germany Haakon Chevalier - friend who ​ Werner Reisenberg -- Leslie Groves -- Military approached Oppenheimer about ​ ​ German physicist in charge of leader of the Manhattan Project spying for Russia. He was designing bomb watched by the FBI, but he was not charged. Otto Hahn -- German physicist ​ who discovered fission Other scientists involved in the Manhattan Project: ​ Aage Niels Bohr George Kistiakowsky Joseph W. Kennedy Richard Feynman Arthur C. Wahl Frank Oppenheimer Joseph Rotblat Robert Bacher Arthur H. Compton Hans Bethe Karl T. Compton Robert Serber Charles Critchfield Harold Agnew Kenneth Bainbridge Robert Wilson Charles Thomas Harold Urey Leo James Rainwater Rudolf Pelerls Crawford Greenewalt Harold DeWolf Smyth Leo Szilard Samuel K. Allison Cyril S. Smith Herbert L. Anderson Luis Alvarez Samuel Goudsmit Edward Norris Isidor I.
    [Show full text]
  • Oral History Interview with Nicolas C. Metropolis
    An Interview with NICOLAS C. METROPOLIS OH 135 Conducted by William Aspray on 29 May 1987 Los Alamos, NM Charles Babbage Institute The Center for the History of Information Processing University of Minnesota, Minneapolis Copyright, Charles Babbage Institute 1 Nicholas C. Metropolis Interview 29 May 1987 Abstract Metropolis, the first director of computing services at Los Alamos National Laboratory, discusses John von Neumann's work in computing. Most of the interview concerns activity at Los Alamos: how von Neumann came to consult at the laboratory; his scientific contacts there, including Metropolis, Robert Richtmyer, and Edward Teller; von Neumann's first hands-on experience with punched card equipment; his contributions to shock-fitting and the implosion problem; interactions between, and comparisons of von Neumann and Enrico Fermi; and the development of Monte Carlo techniques. Other topics include: the relationship between Turing and von Neumann; work on numerical methods for non-linear problems; and the ENIAC calculations done for Los Alamos. 2 NICHOLAS C. METROPOLIS INTERVIEW DATE: 29 May 1987 INTERVIEWER: William Aspray LOCATION: Los Alamos, NM ASPRAY: This is an interview on the 29th of May, 1987 in Los Alamos, New Mexico with Dr. Nicholas Metropolis. Why don't we begin by having you tell me something about when you first met von Neumann and what your relationship with him was over a period of time? METROPOLIS: Well, he first came to Los Alamos on the invitation of Dr. Oppenheimer. I don't remember quite when the date was that he came, but it was rather early on. It may have been the fall of 1943.
    [Show full text]
  • Trinity Transcript
    THE NATIONAL ACADEMIES Committee on International Security and Arms Control 60th Anniversary of Trinity: First Manmade Nuclear Explosion, July 16, 1945 PUBLIC SYMPOSIUM July 14, 2005 National Academy of Sciences Auditorium 2100 C Street, NW Washington, DC Proceedings By: CASET Associates, Ltd. 10201 Lee Highway, Suite 180 Fairfax, VA 22030 (703) 352-0091 CONTENTS PAGE Introductory Remarks Welcome: Ralph Cicerone, President, The National Academies (NAS) 1 Introduction: Raymond Jeanloz, Chair, Committee on International Security and Arms Control (CISAC) 3 Roundtable Discussion by Trinity Veterans Introduction: Wolfgang Panofsky, Chair 5 Individual Statements by Trinity Veterans: Harold Agnew 10 Hugh Bradner 13 Robert Christy 16 Val Fitch 20 Don Hornig 24 Lawrence Johnston 29 Arnold Kramish 31 Louis Rosen 35 Maurice Shapiro 38 Rubby Sherr 41 Harold Agnew (continued) 43 1 PROCEEDINGS 8:45 AM DR. JEANLOZ: My name is Raymond Jeanloz, and I am the Chair of the Committee on International Security and Arms Control that organized this morning’s symposium, recognizing the 60th anniversary of Trinity, the first manmade nuclear explosion. I will be the moderator for today’s event, and primarily will try to stay out of the way because we have many truly distinguished and notable speakers. In order to allow them the maximum amount of time, I will only give brief introductions and ask that you please turn to the biographical information that has been provided to you. To start with, it is my special honor to introduce Ralph Cicerone, the President of the National Academy of Sciences, who will open our meeting with introductory remarks. He is a distinguished researcher and scientific leader, recently serving as Chancellor of the University of California at Irvine, and his work in the area of climate change and pollution has had an important impact on policy.
    [Show full text]
  • Magic of Muons: How a Magnet from the 90’S Could Usher in a New Age of Physics
    Magic of Muons: How a magnet from the 90’s could usher in a new age of physics Joe Grange Argonne National Laboratory [email protected] To d ay ‣ Broad introduction to particle physics - what are we doing? why? ‣ The amazing muon as a tool for science and society ‣ History and future of “g-2” measurements - how an old magnet could revolutionize the field ‣ Wrapup 2 ‣ Broad introduction to particle physics - what are we doing? why? ‣ The amazing muon as a tool for science and society ‣ History and future of “g-2” measurements - how an old magnet could revolutionize the field ‣ Wrapup 3 Physics in a nutshell ‣ Broadly, here at Fermilab and around the 1 mm world we try to understand the world in terms of it’s most basic building blocks and how they interact 3x10-7 mm 1x10-7 mm 1x10-12 mm < 1x10-15 mm 4 Incredible richness in the sensory world arises from just a few particles ‣ Very small number of ingredients form everything you can see, feel or touch: p n e γ" 5 Amazing variety from such simple ingredients 6 Amazing variety from such simple ingredients 7 19th century hubris “In this field, almost everything is already p discovered, and all that remains is to fill a few unimportant holes.” (1878) Johann Philipp Gustav von Jolly advising Max Planck n not to pursue physics e 1918 γ" 8 Good thing Planck didn’t listen... ‣ His theory not only described never before seen phenomena, it revolutionized the fundamental description of the atom von Jolly was so happy with! ✓ 9 Since then..
    [Show full text]
  • Wave-Particle Duality
    Wave-particle duality https://xkcd.com/967 History of the Standard Model, Part 2 July 8, 2020 1 Fundamental Forces https://xkcd.com/1489 History of the Standard Model, Part 2 July 8, 2020 2 QuarkNet Summer Session for Teachers: The Standard Model and Beyond Allie Reinsvold Hall https://quarknet.org/content/quarknet-summer- session-teachers-2020 Summer 2020 History of the Standard Model, Part 2 July 8, 2020 3 Course overview What are the fundamental building blocks that make up our universe? Mission: overview of the past, present, and future of particle physics 1. History of the Standard Model, Part 1: Ancient Greeks to Quantum Mechanics 2. History of the Standard Model, Part 2: Particle zoo and the Standard Model 3. Particle physics at the Large Hadron Collider (LHC) 4. Beyond the Standard Model at the LHC 5. Neutrino physics 6. Dark matter and cosmology Goal: Bring you to whatever your next level of understanding is and provide resources for when you teach. Not everyone is at the same level and that’s okay. History of the Standard Model, Part 2 July 8, 2020 4 Loose ends from last week • Lost Discoveries by Dick Teresi • Derivation of the energy and time relationship in Heisenberg’s uncertainty principle: https://quarknet.org/content/note- consistency-complimentary-variables https://quarknet.org/sites/default/fil es/Heisenberg%20and%20Diffraction. pdf https://quarknet.org/sites/default/fil es/Heisenberg%20and%20Energy.pdf • Fill out the weekly report if you haven’t already done so! • Everyone so far agreed to share their contact info – thanks! History of the Standard Model, Part 2 July 8, 2020 5 Loose ends from last week Excellent question on the weekly survey: “How can we help students understand the connection between particles and waves that is required in the quantum world?” You all are better equipped to answer that than I am – time for breakout discussions! Introduce yourself to today’s group.
    [Show full text]
  • Measurement of the Muon Lifetime
    Measurement of the Muon Lifetime Carl W. Akerlof September 10, 2009 Overview The only fundamental constituents of matter that are important for most of science are electrons, protons, and neutrons. It was thus a surprise when Carl D. Anderson and his student, Seth H. Neddermeyer, discovered1 the muon in cosmic rays in 1936. This unexpected result was confirmed2 independently by J.C. Street and E.C. Stevenson almost immediately. With the absence of strong interactions, the muon mass, roughly 200 times greater than the electron and 10 times smaller than the proton, make these particles extremely penetrating if sufficiently energetic. In this experiment, you will observe tens of thousands of cosmic ray-generated muons that slow down and stop in a large tank of liquid scintillator. With care, you will be able to determine the lifetime of a muon at rest to a precision of the order of one percent. In doing so, you will find evidence for muonic atoms formed by the capture of negative muons by carbon nuclei. Since muons in a vacuum can only decay into electrons, electron neutrinos and muon neutrinos, all fundamental particles, the mean lifetime is an important number that directly determines the weak force coupling constant, GF, to high accuracy. This experiment stresses the importance of accurate time calibrations and requires a variety of statistical methods for extracting accurate results and determining their significance. Historical Background One of the major successes of physics in the 20th century was the discovery and characterization of the fundamental constituents of matter. A number of important 1897 e- discovered J.
    [Show full text]
  • An Atomic History Chapter 2
    An Atomic History 0-3 8/11/02 7:31 AM Page 18 Chapter Two 19 THE FERMI-SZILARD PILE AND URANIUM RESEARCH The first government funding for nuclear research was allocated to purchase graphite and uranium oxide for the chain reaction experiments being organized by Fermi and World War II and the Manhattan Project Szilard at Columbia University in February 1940.2 This work, which began in New York 2 City, soon spread to Princeton, the University of Chicago, and research institutions in California.3 Even at this stage, the scientists knew that a chain reaction would need three major components in the right combination: fuel, moderator, and coolant. The fuel would contain the fissile material needed to support the fission process. The neutrons generated by the fission process had to be slowed by the moderator so that they could initiate addi- tional fission reactions. The heat that resulted from this process had to be removed by the coolant. Fermi’s initial research explored the possibility of a chain reaction with natural urani- The 1930s were a time of rapid progress in the development of nuclear physics. um. It was quickly determined that high-purity graphite served as the best neutron moder- Research accelerated in the early years of the Second World War, when new developments ator out of the materials then available.4 After extensive tests throughout 1940 and early were conceived and implemented in the midst of increasing wartime urgency. American 1941, Fermi and Szilard set up the first blocks of graphite at Columbia University in government interest in these developments was limited at first, but increased as the war September 1941.
    [Show full text]
  • A Nature of Science Guided Approach to the Physics Teaching of Cosmic Rays
    A Nature of Science guided approach to the physics teaching of Cosmic Rays Dissertation zur Erlangung des akademischen Grades Doktorin der Philosophie (Dr. phil. { Doctor philosophiae) eingereicht am Fachbereich 4 Mathematik, Naturwissenschaften, Wirtschaft & Informatik der Universit¨atHildesheim vorgelegt von Rosalia Madonia geboren am 20. August 1961 in Palermo 2018 Schwerpunkt der Arbeit: Didaktik der Physik Tag der Disputation: 21 Januar 2019 Dekan: Prof. Dr. M. Sauerwein 1. Gutachter: Prof. Dr. Ute Kraus 2. Gutachter: Prof. Dr. Peter Grabmayr ii Abstract This thesis focuses on cosmic rays and Nature of Science (NOS). The first aim of this work is to investigate whether the variegated aspects of cosmic ray research -from its historical development to the science topics addressed herein- can be used for a teaching approach with and about NOS. The efficacy of the NOS based teaching has been highlighted in many studies, aimed at developing innovative and more effective teaching strategies. The fil rouge that we propose unwinds through cosmic ray research, that with its century long history appears to be the perfect topic for a study of and through NOS. The second aim of the work is to find out what knowledge the pupils and students have regarding the many aspect of NOS. To this end we have designed, executed, and analyzed the outcomes of a sample-based investigation carried out with pupils and students in Palermo (Italy), T¨ubingenand Hildesheim (Germany), and constructed around an open-ended ques- tionnaire. The main goal is to study whether intrinsic differences between the German and Italian samples can be observed. The thesis is divided in three parts.
    [Show full text]
  • Carl David Anderson Biographical Memoir
    NATIONAL ACADEMY OF SCIENCES C A R L D A V I D A NDERSON 1905—1991 A Biographical Memoir by WILLIAM H. PICKERING Any opinions expressed in this memoir are those of the author(s) and do not necessarily reflect the views of the National Academy of Sciences. Biographical Memoir COPYRIGHT 1998 NATIONAL ACADEMIES PRESS WASHINGTON D.C. CourtesyofInstituteArchives,CaliforniaInstituteofTechnology,Pasadena CARLDAVIDANDERSON September3,1905–January11,1991 BYWILLIAMH.PICKERING ESTKNOWNFORHISdiscoveryofthepositiveelectron, Borpositron,CarlDavidAndersonwasawardedthe NobelPrizeinphysicsin1936atagethirty-one.Thedis- coveryofthepositronwasthefirstofthenewparticlesof modernphysics.Electronsandprotonshadbeenknown andexperimentedwithforaboutfortyyears,anditwas assumedthatthesewerethebuildingblocksofallmatter. Withthediscoveryofthepositron,anexampleofanti- matter,allmanneroftheoreticalandexperimentalpossi- bilitiesarose.TheRoyalSocietyofLondoncalledCarl’s discovery“oneofthemostmomentousofthecentury.” BornonSeptember3,1905,inNewYorkCity,Carlwas theonlysonofSwedishimmigrantparents.Hisfather,the seniorCarlDavidAnderson,hadbeenintheUnitedStates since1896.WhenCarlwassevenyearsold,thefamilyleft NewYorkforLosAngeles,whereCarlattendedpublic schoolsandin1923enteredtheCaliforniaInstituteof Technology.Caltechhadopeneditsdoorsin1921with RobertA.Millikan,himselfaNobellaureate,aschiefex- ecutive.TogetherwithchemistArthurA.Noyesandas- tronomerGeorgeElleryHale,Millikanestablishedthehigh standardofexcellenceandthesmallstudentbodythat todaycontinuestocharacterizeCaltech.
    [Show full text]
  • Lecture 10 Fall 2018 Semester Prof
    Physics 56400 Introduction to Elementary Particle Physics I Lecture 10 Fall 2018 Semester Prof. Matthew Jones Elementary Particles • Atomic physics: – Proton, neutron, electron, photon • Nuclear physics: – Alpha, beta, gamma rays • Cosmic rays: – Something charged (but what?) • Relativistic quantum mechanics (Dirac, 1928) – Some solutions described electrons (with positive energy) – Other solutions described electrons with negative energy – Dirac came up with an elegant explanation for to think about this… The Dirac Sea • Dirac proposed that all electrons have negative charge. • Normal electrons have positive energy. • All negative-energy states are populated and form the Dirac sea. • The Pauli exclusion principle explains why positive- energy electrons can’t reach a lower energy state – those states are already populated • The only way to observe an electron in the sea would be to give it a positive energy. The Dirac Sea Energy Lowest positive-energy +푚푒 state corresponds to an electron at rest. It can’t fall into the sea −푚푒 because those states are already filled. The Dirac Sea Energy Now we have a positive energy electron, and a hole in the sea. +푚푒 The absence of a negative charge looks −푚푒 like a positive charge. This describes pair production. The Dirac Sea Energy Now that there is a hole in the sea, a positive energy electron can fall +푚푒 into it, releasing energy. −푚푒 This corresponds to electron-positron annihilation. Positrons • This explanation was not immediately interpreted as a prediction for a new particle • However, Carl Anderson observed “positive electrons” in cosmic rays in 1933. • Nobel prize in 1934. • Anti-particles are a natural consequence of special relativity and quantum mechanics.
    [Show full text]
  • Character List
    Character List - Bomb ​ Use this chart to help you keep track of the hundreds of names of physicists, freedom fighters, government officials, and others involved in the making of the atomic bomb. Scientists Political/Military Leaders Spies Robert Oppenheimer - Winston Churchill -- Prime Klaus Fuchs - physicist in ​ ​ ​ designed atomic bomb. He was Minister of England Manhattan Project who gave accused of spying. secrets to Russia Franklin D. Roosevelt -- ​ Albert Einstein - convinced President of the United States Harry Gold - spy and Courier ​ ​ U.S. government that they for Russia KGB. Narrator of the needed to research fission. Harry Truman -- President of story ​ the United States Enrico Fermi - created first Ruth Werner - Russian spy ​ ​ chain reaction Joseph Stalin -- dictator of the ​ Tell Hall -- physicist in Soviet Union ​ Igor Korchatov -- Russian Manhattan Project who gave ​ physicist in charge of designing Adolf Hitler -- dictator of secrets to Russia ​ bomb Germany Haakon Chevalier - friend who ​ Werner Reisenberg -- Leslie Groves -- Military approached Oppenheimer about ​ ​ German physicist in charge of leader of the Manhattan Project spying for Russia. He was designing bomb watched by the FBI, but he was not charged. Otto Hahn -- German physicist ​ who discovered fission Other scientists involved in the Manhattan Project: ​ Aage Niels Bohr George Kistiakowsky Joseph W. Kennedy Richard Feynman Arthur C. Wahl Frank Oppenheimer Joseph Rotblat Robert Bacher Arthur H. Compton Hans Bethe Karl T. Compton Robert Serber Charles Critchfield Harold Agnew Kenneth Bainbridge Robert Wilson Charles Thomas Harold Urey Leo James Rainwater Rudolf Pelerls Crawford Greenewalt Harold DeWolf Smyth Leo Szilard Samuel K. Allison Cyril S. Smith Herbert L. Anderson Luis Alvarez Samuel Goudsmit Edward Norris Isidor I.
    [Show full text]