Economou From Quarks to the Universe A Short Physics Course Second Edition www.com From Quarks to the Universe www. Economou From Quarks to the Universe A Short Physics Course Second Edition 123 www. Economou FORTH, IESL University of Crete Iraklion Greece ISBN 978-3-319-20653-0 ISBN 978-3-319-20654-7 (eBook) DOI 10.1007/978-3-319-20654-7 Library of Congress Control Number: 2015954584 Springer Cham Heidelberg New York Dordrecht London © Springer international Publishing Switzerland 2011, 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed.
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Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.com There is, of course, an immense liberating role of Science at a central existential level. It is what Aristotle was saying about “θαυμάζειν”. Science humanizes us, liberating us from our animal instincts, just because it makes us wondering and at the same time desiring to explain…Yet it shows us our limits and our mortality… Thus Science is something immeasurably precious….Science can help us approach anew the real poetic and mythical dimension of human existence. Castoriadis The Castoriadis quote is from the Castoriadis and Evangelopoulos book, Philosophy and Science, (Editions Eurasia, Athens, 2010) www.com To Athanasia www.com Preface to the Second Edition This book in this second edition has been enlarged (its size now is more than twice that of the first edition) and has been enriched in order to also serve as a senior undergraduate textbook; nevertheless, it retains its main feature of deriving most of the basic formulae governing the behavior of the various structures of the physical word by applying “a little thinking” and employing dimensional considerations.
Explicitly, in each chapter, besides more background information, new sections have been added: One of them includes a summary of the main relevant formulae; another contains many multiple choice questions/statements (their correct answers are given at the end of the book). Finally, there are two more sections in every chapter involving solved and unsolved problems respectively. Moreover, six new appendices have been added in this new edition: In two of them a summary of the subjects of Electrodynamics of Continuous Media and of Thermodynamics and Statistical Mechanics is presented. These two appendices together with the last three, presenting a list of the required background concepts, formulae, and numbers, make the book to a large degree self-contained.
In another new appendix a few basic concepts regarding semiconductor physics are introduced. As I mentioned before, this book in this second edition may well serve a senior undergraduate course: The students in such a course will be asked to wrap up their basic knowledge and reasoning and apply them to derive and understand the basic features of the physical world. Of course, as it was stated in the preface to the first edition, graduate students, research scientists, physics teachers and others may find this book intellectually stimulating and entertaining. I would like thank again my colleague, Prof.
Charmandaris, for reading the entire text of this second edition and for making many useful suggestions. Of course, whatever misprints or misrepresentations remained are my own responsi- bility only. I am also grateful to Ms. Maria Dimitriadi for her invaluable help in bringing my manuscript to its final form.
Economou ix www.com Preface to the First Edition This short book grew out of lectures presented to different audiences (physics students, physicists, material scientists, engineers) and on various occasions (col- loquia and seminars in physics and other departments, conferences, special events). The main purpose of these lectures and, obviously, of the present book is to show that basic formulae concerning the various structures of the physical world pop out quickly, if some basic ideas, the universal physical constants, and dimensional considerations are exploited. Of course, as R. Feynman pointed out, “a little thinking has to be applied too”.
The basic ideas include the three cornerstones of science, namely the atomic idea, the wave-particle duality, and the minimization of free energy as the necessary and sufficient condition for equilibrium (these are presented in Chaps. These fundamental ideas exhibit their worth when accompanied by the values of the physical constants: the universal ones, h; c; the coupling constants of the four interactions, G; e; gw ; gs and the masses of the elementary particles, mp ; mn ; me ; mw ;. An important consequence of the atomic idea is that the rel- evant (for each case) physical constants will appear in the quantities characterizing the various structures of the world either microscopic or macroscopic. Combining this last observation—often overlooked—with dimensional analysis, presented in Chap.
5, and “a little thinking”, one can obtain, in several cases, an amazing short-cut derivation of formulae concerning the various structures of Nature from the smallest (baryons and mesons) to the whole Universe, as shown Chaps. In each one of these 8 chapters, in parallel with a demonstration of the method just outlined, a condensed (sometimes too condensed) introduction to the relevant subject matter together with a few physical remarks are presented. I must admit that the main fronts on which our scientific horizons are widened, namely the small, the large, and the complex could not be treated even remotely adequately in this short book. Actually the complex, as represented by the living matter, was too complex for our simple method; so it was left out completely (however, see the epilogue).
The large (cosmology) and the small (elementary particles) tend to converge to a unified subject (the snake in Fig.2, is biting xi www.com xii Preface to the First Edition its tail) fed with novel observational data from special instruments mounted usually on satellites, and boosted by high experimental expectations from the Large Hadron Collider. Nevertheless, in these fields there are several open fundamental questions concerning conditions well beyond our present or near future experimental capa- bilities. This vacuum of confirmed knowledge is filled with new intriguing, imaginative ideas and novel proposed theories (such as supersymmetry, string theory, M-theory, see reference [P1]) which, if established, will radically change our world view. In spite of the wider interest in these ideas and theories and their high intellectual value, I decided for several reasons to restrict myself in the present book to experimentally or observationally tested ideas and theories.
The intended readers of this book are senior undergraduate or graduate students in Physics, Engineering, Applied Mathematics, Chemistry, and Material Science. They may find the book a useful supplement to their courses as a concise overall picture of the physical world. Research physicists, physics teachers, and other scientists may also find this short book intellectually stimulating and entertaining. The required background is no more than a working familiarity with the Science/ Engineering material taught in the first University year.
I am deeply indebted to my colleague, Prof. Charmandaris, for his encour- agement during the writing of this book and for reading my entire manuscript and making many useful suggestions. Of course, whatever misprints or misrepresen- tations remained are my own responsibility only. I am also grateful to Ms.
Maria Dimitriadi for her invaluable help in bringing my manuscript to its final form. Economou January 2011 www.com Contents 1 Introduction: The World According to Physics .1 The Nature of Physics.2 The Subject Matter of Physics .3 Various Branches of Physics .4 The Main Points of This Book: Basic Ideas Applied to Equilibrium Structures of Matter. 7 Part I Three Key-Ideas and a Short-Cut 2 The Atomic Idea .2 The Elementary Particles of Matter .3 The Interactions and Their Elementary Interaction-Carrying-Particles .6 Summary of Important Concepts, Relations, and Data .7 Multiple-Choice Questions/Statements. 25 3 The Wave-Particle Duality .1 Concepts and Formulae .2 The Properties of the Structures of the World at Every Scale Are of Quantum Nature.
If They Were Not, We Would Not Exist .3 Heisenberg’s Uncertainty Principle .4 Pauli’s Exclusion Principle .5 Quantum Kinetic Energy in View of Heisenberg and Pauli Principles .com xiv Contents 3.6 Schrödinger’s Principle of Spectral Discreteness .7 Summary of Important Concepts and Formulae .8 Multiple-Choice Questions/Statements. 49 4 Equilibrium and Minimization of Total Energy .2 Conservation of Energy and the First Law .3 Entropy and the Second Law .7) as a Source of Thermodynamic Relations .5 Maximum Work, Gibbs’ Free Energy, and Chemical Potential .6 Extensive and Intensive Thermodynamic Quantities .7 Summary of Important Relations .8 Multiple-Choice Questions/Statements .11 The Three Phases of Matter (Solid (s), Liquid (l), Gas (g)). 66 5 Dimensional Analysis: A Short-Cut to Physics Relations .1 Outline of the Method.2 Relations Regarding Some Eigenfrequencies .3 Some Relations in Fluid Dynamics .4 Thermodynamic Relations Revisited .5 Waves in Extended, Discrete or Continuous, Media .6 Summary of Important Formulae .7 Multiple-Choice Questions/Statements. 81 Part II Interactions 6 Photons: Messengers and Connectors .2 Photons in Equilibrium .1 Determine the Thermodynamic Quantities of a Photon Gas in Equilibrium by Employing Dimensional Analysis .2 Determine the Total E/M Energy, I, Emitted by a Black Body of Temperature T Per Unit Time and Per Unit Area by Employing Dimensional Analysis .com Contents xv 6.3 How Is the Emitted I x Black Body E/M Energy Per Unit Time, Per Unit Frequency, and Per Unit Area Distributed Among the Various Frequencies? .3 Emission of Photons by Accelerating Charges .1 Radiation by a Moving Particle of Electric Charge q .2 Radiation by a Neutral System Pwith an Oscillating Electric Dipole Moment p ¼ qi r i .4 Scattering of Photons by Charged Particles, Atoms, Molecules .5 Scattering of Photons by Macroscopic Particles .6 Total Scattering Cross-Section and Mean Free Path .7 Quantities Characterizing the E/M Behavior of Solids and Liquids .8 Calculation of the Conductivity r and the Permittivity e .9 Summary of Important Formulae .10 Multiple-Choice Questions/Statements.
103 7 The Other Interactions .2 Strong Interactions Involving Quarks and Gluons .1 Newtonian Formulation of Gravitational Interactions .2 Gravitational Interactions According to Einstein .3 Two Model Systems Allowing Exact Solutions of the GTR .4 Universal Physical Constants and the Planck System of Units .5 Summary of Important Formulae .6 Multiple-Choice Questions/Statements. 119 Part III Structures Held Together by Strong Interactions 8 From Quarks and Gluons to Hadrons.2 Baryons and Mesons.3 Estimating the Rest Energy of Proton or Neutron .com xvi Contents 8.4 Multiple-Choice Questions/Statements. 131 9 From Protons and Neutrons to Nuclei .2 Calculating the Total Energy .3 Minimizing the Total Energy .4 Questions and Answers .5 Summary of Important Formulae and Related Comments.6 Multiple-Choice Questions/Statements. 151 Part IV Structures Held Together by Electromagnetic Interactions 10 From Nuclei and Electrons to Atoms .2 Size and Relevant Energy of Atoms .4 Energy Ordering of the Atomic Orbitals wnlm .5 The Structure of the Periodic Table of the Elements .6 Summary of Important Relations .7 Multiple-Choice Questions/Statements.
166 11 From Atoms to Molecules.2 The Residual Electric Interaction Between Two Atoms .3 Estimates Based on Dimensional Analysis .4 Linear Combination of Atomic Orbitals (LCAO) .5 Hybridization of Atomic Orbitals .6 Summary of Important Relations .7 Multiple-Choice Questions/Statements .2 Some Common Crystal Lattices .3 Types of Bonding in Condensed Matter .4 Dimensional Analysis Applied to Solids .com Contents xvii 12.