The modern revolution in physics

124 Pages·2000·1.498 MB·English

by  Crowell B.

The Modern
Revolution in Physics
Benjamin Crowell
Book 6 in the Light and Matter series of introductory physics textbooks
www.lightandmatter.com

The Modern
Revolution
in Physics
The Light and Matter series of
introductory physics textbooks:
1 Newtonian Physics
2 Conservation Laws
3 Vibrations and Waves
4 Electricity and Magnetism
5 Optics
6 The Modern Revolution in Physics
The Modern Revolution
in Physics
Benjamin Crowell
www.lightandmatter.com
Light and Matter
www.lightandmatter.com
© 2000 by Benjamin Crowell
All rights reserved.
Edition 2.0 — 2000
rev. 2000-08-13
Contents
1 Relativity, Part I 11
2 Relativity, Part II 29
3 Rules of Randomness 43
4 Light as a Particle 61
5 Matter as a Wave 75
6 The Atom 95
Contents
1 Relativity, Part I 11
1.1 The Principle of Relativity.................... 12
1.2 Distortion of Time and Space .............. 13
1.3 Applications ......................................... 20
Summary...................................................... 26
Homework Problems.................................... 27
3 Rules
of Randomness 43
3.1 Randomness Isn’t Random ................. 44
3.2 Calculating Randomness..................... 45
3.3 Probability Distributions....................... 48
2 Relativity, Part II 29
3.4 Exponential Decay and Half-Life ......... 51
2.1 Invariants............................................. 30 3.5(cid:242) Applications of Calculus ..................... 56
2.2 Combination of Velocities.................... 30 Summary...................................................... 58
2.3 Momentum and Force ......................... 32 Homework Problems.................................... 59
2.4 Kinetic Energy ..................................... 33
2.5 Equivalence of Mass and Energy........ 35
2.6* Proofs................................................. 38
Summary...................................................... 40
Homework Problems.................................... 41
4 Light as a Particle 61
4.1 Evidence for Light as a Particle........... 62
4.2 How Much Light Is One Photon?......... 63
4.3 Wave-Particle Duality .......................... 67
4.4 Photons in Three Dimensions ............. 71
Summary...................................................... 72
Homework Problems.................................... 73
6 The Atom 95
6.1 Classifying States................................ 96
6.2 Angular Momentum
in Three Dimensions ......................... 97
6.3 The Hydrogen Atom............................. 99
6.4* Energies of States in Hydrogen ....... 102
6.5 Electron Spin ..................................... 104
6.6 Atoms With More Than One Electron 105
Summary.................................................... 107
Homework Problems.................................. 108
5 Matter as a Wave 75
5.1 Electrons as Waves............................. 76
5.2*(cid:242) Dispersive Waves................................ 80
5.3 Bound States....................................... 82
5.4 The Uncertainty Principle
and Measurement ............................. 84
5.5 Electrons in Electric Fields .................. 88
5.6*(cid:242) The Schrödinger Equation................... 89
Summary...................................................... 92
Exercises 111
Homework Problems.................................... 93
Glossary 115
Index 117
Photo Credits 121
Useful Data 124