Table Of ContentUnderstanding the Universe
Understanding the Universe
The Physics of the Cosmos
from Quasars to Quarks
Andrew Norton
The Open University
First edition published 2021
by CRC Press
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Library of Congress Cataloging‑in‑Publication Data
Names: Norton, Andrew J., author.
Title: Understanding the universe : the physics of the cosmos from quasars to quarks /
Andrew John Norton, The Open University.
Description: First edition. | Boca Raton : CRC Press, 2021. | Includes bibliographical
references and index.
Identifiers: LCCN 2020056848 (print) | LCCN 2020056849 (ebook) |
ISBN 9780367748050 (hardback) | ISBN 9781003164661 (ebook)
Subjects: LCSH: Cosmology. | Particles (Nuclear physics)
Classification: LCC QB981 .N775 2021 (print) | LCC QB981 (ebook) |
DDC 523.1--dc23 LC record available at https://lccn.loc.gov/2020056848LC
ebook record available at https://lccn.loc.gov/2020056849
ISBN: 9780367748050 (hbk)
ISBN: 9780367759322 (pbk)
ISBN: 9781003164661 (ebk)
Typeset in Times
by Deanta Global Publishing Services, Chennai, India
Contents Contents
Dedication
For Joseph John Norton (1932–2020)
Contents
Author ....................................................................................................................xiii
Chapter 1 Quasars to Quarks ................................................................................1
1.1 Cosmology and Particle Physics ................................................3
1.2 Understanding How the Universe Works ..................................4
Chapter 2 The Physical World ..............................................................................7
2.1 The World of Atoms ..................................................................7
2.1.1 Atomic Components .....................................................7
2.1.2 Molecules and States of Matter ....................................9
2.2 The World in Motion ...............................................................10
2.2.1 Describing Motion ......................................................10
2.2.2 Motion in a Circle .......................................................12
2.2.3 Newton’s Laws of Motion ..........................................12
2.2.4 Relativistic Motion .....................................................14
2.3 The World of Energy ...............................................................16
2.4 The World of Light ..................................................................18
PART I The Small-Scale Universe
Chapter 3 Quantized Energy ...............................................................................25
3.1 The Quantum World ................................................................25
3.2 The Spectral Fingerprint of Hydrogen ....................................26
3.3 The Energy of an Atom ...........................................................27
3.4 Energy Levels and Transitions ................................................28
3.5 The Energy Levels of the Hydrogen Atom ..............................29
3.6 Quantum States and Quantum Numbers .................................31
3.7 Energy Levels in General ........................................................34
Chapter 4 Quantum Uncertainty .........................................................................37
4.1 Indeterminacy and Probability ................................................37
4.2 Modelling Atoms .....................................................................39
4.3 The Uncertainty Principle .......................................................41
4.4 Quantum Technology ..............................................................43
vii
viii Contents
Chapter 5 Atoms .................................................................................................45
5.1 Atoms and Ions with One Electron .........................................45
5.2 Atoms and Ions with Two Electrons ........................................46
5.3 Atoms with Three or More Electrons ......................................48
5.4 The Periodic Table of the Elements .........................................49
Chapter 6 Nuclei .................................................................................................53
6.1 Mass and Energy .....................................................................54
6.2 Alpha-Decay ............................................................................55
6.3 Beta-Decay ..............................................................................56
6.4 Gamma-Decay .........................................................................58
6.5 Half-Life ..................................................................................58
6.6 Nuclear Fission ........................................................................59
6.7 Nuclear Fusion .........................................................................60
Chapter 7 Particles ..............................................................................................63
7.1 Leptons ....................................................................................63
7.2 Quarks .....................................................................................64
7.3 High-Energy Reactions ...........................................................66
7.4 A Summary of the Universe at Small Scales ..........................68
PART II The Large-Scale Universe
Chapter 8 Observing the Universe ......................................................................73
8.1 Telescopes ................................................................................73
8.1.1 Refracting Telescopes .................................................74
8.1.2 Reflecting Telescopes .................................................75
8.1.3 The Characteristics of Astronomical Telescopes .......76
8.2 Astronomical Detectors ...........................................................77
8.2.1 Photometry .................................................................77
8.2.2 Spectroscopy ..............................................................78
8.3 Beyond the Visible ...................................................................80
8.3.1 Radio Astronomy .......................................................81
8.3.2 Radio Telescopes ........................................................82
8.3.3 Radio Interferometry ..................................................83
8.4 Astronomy at High Energies ...................................................85
8.4.1 X-Ray and Gamma-Ray Astronomy ..........................85
8.4.2 X-Ray and Gamma-Ray Telescopes ...........................86
8.4.3 High-Energy Photon Detectors ..................................88
8.5 Multi-Messenger Astrophysics ................................................89
Contents ix
Chapter 9 The Expanding Universe ....................................................................91
9.1 The Distances to Galaxies .......................................................91
9.1.1 Geometrical Methods .................................................91
9.1.2 Flux and Luminosity ..................................................93
9.1.3 Standard Candles .......................................................94
9.2 The Apparent Speed of Galaxies .............................................96
9.3 The Hubble Relationship .........................................................98
9.4 Expanding Space ...................................................................100
9.5 Strange Ideas .........................................................................101
9.6 The Age of the Universe ........................................................104
Chapter 10 The Cooling Universe ......................................................................107
10.1 Black-Body Radiation ............................................................107
10.2 The Cosmic Microwave Background ....................................109
10.3 The Hot Big Bang ..................................................................111
PART III Universal Processes
Chapter 11 Electromagnetic Interactions ............................................................115
11.1 Electric and Magnetic Forces ................................................115
11.2 Electromagnetic Fields and Radiation ...................................116
11.3 Quantum Electrodynamics ....................................................119
Chapter 12 Strong Interactions ...........................................................................123
12.1 Quarks and Gluons ................................................................123
12.2 Quantum Chromodynamics ..................................................125
Chapter 13 Weak Interactions .............................................................................129
13.1 Comparisons between Fundamental Interactions .................129
13.2 W and Z Bosons ....................................................................130
13.3 The Survival of the Neutron ..................................................132
Chapter 14 Gravitational Interactions .................................................................135
14.1 Orbits and Kepler’s Laws.......................................................135
14.2 Newton’s Gravity ...................................................................136
14.3 Einstein’s Gravity ..................................................................138
14.4 Tests of Curved Spacetime ....................................................139
14.5 Gravitational Radiation .........................................................142
14.6 Quantum Gravity ...................................................................144
x Contents
Chapter 15 Unified Theories ...............................................................................147
15.1 Electroweak Unification ........................................................149
15.2 Grand Unification ..................................................................150
15.3 Superunification: Strings and Branes ....................................151
PART IV The Universe through Time
Chapter 16 The History of the Universe .............................................................157
16.1 Time, Space, Temperature, and Energy ................................157
16.2 The Very Early Universe .......................................................159
16.3 Inflation .................................................................................160
16.4 The Quark–Lepton Era ..........................................................162
16.5 The Hadron Era .....................................................................164
16.6 Primordial Nucleosynthesis ...................................................165
16.7 Structure in the Universe .......................................................167
Chapter 17 The Universe Today .........................................................................171
17.1 Large-Scale Structure ............................................................171
17.2 Active Galaxies .....................................................................173
17.3 The Milky Way and Other Galaxies .....................................177
17.4 The Formation of Stars and Planets ......................................179
17.5 The Evolution of Stars ...........................................................181
17.5.1 Life on the Main Sequence ......................................182
17.5.2 Post-Main Sequence Evolution .................................184
17.5.3 Stellar Death .............................................................186
17.5.4 Accreting Compact Binary Stars .............................189
17.6 The Solar System ...................................................................191
17.6.1 The Sun ....................................................................191
17.6.2 Terrestrial Planets and Asteroids .............................192
17.6.3 Giant Planets and Their Satellites ............................194
17.6.4 The Outer Limits ......................................................195
17.7 Exoplanets and How to Find Them .......................................196
17.7.1 The Radial Velocity Technique ................................197
17.7.2 The Transit Technique ..............................................198
17.7.3 Exoplanetary Systems ..............................................199
17.8 Life in the Universe ...............................................................202
17.8.1 The Drake Equation .................................................202
17.8.2 The Fermi Paradox ...................................................203
17.8.3 The Anthropic Principle ...........................................205
