Light and Waves: A Conceptual Exploration of Physics

Preface
Contents
1 Theories of Light
1.1 Ancient Ideas About Light
1.1.1 Extramission Theory
1.1.2 Particle Theory
1.2 Islamic Golden Age
1.3 The Particle-Wave Debate
1.3.1 Wave Theory
1.4 Particle-Wave Duality
1.4.1 Today
1.5 Looking Ahead
1.6 Summary
1.7 Exercises
Exercises
Part IWaves
2 Properties of Waves
2.1 Introduction to Waves
2.1.1 What Is a Wave?
2.1.2 Amplitude and Wavelength
2.2 Characterizing Waves
2.2.1 Types of Waves
2.2.2 Transverse and Longitudinal Waves
2.2.3 Waves in 1, 2, and 3 Dimensions
2.3 Speed and Velocity
2.3.1 Speed and Velocity Equations
2.3.2 Speed of Light
2.3.3 Measuring the Speed of Light*
2.3.4 Speed of Light in a Medium
2.3.5 High Frequency Stock Market Trading and the Speed of Light*
2.4 Frequency and Period
2.4.1 Cars on a Road Analogy
2.4.2 Relating Velocity, Frequency, and Wavelength
2.4.3 Frequency
2.4.4 Frequency and Wavelength in a New Medium
2.5 Summary
2.6 Exercises
3 Superposition
3.1 Superposition of Waves
3.1.1 The Superposition Principle
3.1.2 Superposition with Different Frequencies
3.1.3 Constructive and Destructive Interference
3.1.4 Oscillations in Time
3.1.5 Constructive and Destructive Interference Examples*
3.1.6 Beating Patterns
3.2 Standing Waves
3.2.1 Reflection at Boundaries
3.2.2 Standing Waves from Reflected Waves and Superposition
3.2.3 Standing Waves Between Two Boundaries
3.3 Interference
3.3.1 Thin-Film Interference
3.3.2 Examples of Thin-Film Interference*
3.3.3 Interferometers and the Lack of an Aether*
3.4 Diffraction
3.4.1 Diffraction Through Holes and Around Obstacles
3.4.2 Huygens's Principle
3.5 Combining Diffraction and Interference
3.5.1 Double-Slit Experiment
3.5.2 Double-Slit Experiment Analysis*
3.5.3 Diffraction Gratings*
3.5.4 Single-Slit Experiment and Analysis*
3.5.5 The Arago-Poisson Spot*
3.5.6 Babinet's Principle
3.6 Structural Coloration*
3.7 Summary
3.8 Exercises
Exercises
4 Wave Energy
4.1 Energy and Power
4.1.1 Energy
4.1.2 Energy Units
4.1.3 Wave Energy
4.1.4 Power
4.1.5 Energy Density and Power Density
4.2 Spectra
4.2.1 Intensity Spectra
4.2.2 Continuous and Line Spectra
4.2.3 Transmission Spectra
4.2.4 Absorption Spectra*
4.3 Resonance
4.3.1 Resonance and Coupling
4.3.2 Two Resonance Examples with String Waves*
4.3.3 Resonance with Electromagnetic Waves
4.3.4 Resonance with Microwaves and Infrared Light*
4.3.5 The Tacoma Narrows and Millennium Bridges*
4.3.6 Resonance is Reversible
4.4 Non-Resonant Energy Transfer
4.4.1 Abrupt Energy Transfer to Waves
4.4.2 Energy Loss From Damping
4.5 Summary
4.6 Exercises
5 Doppler Effects, Redshifts, and Blueshifts
5.1 Doppler Effect Concepts
5.1.1 The Doppler Effect for Sound Waves
5.1.2 Cars on a Road Analogy
5.1.3 Doppler Effect Applications*
5.1.4 Red and Blue Shifts
5.1.5 Gravitational and Cosmological Redshifts*
5.2 Doppler Effect Equations
5.2.1 Moving Observer Case
5.2.2 Moving Source Equation
5.2.3 General Equation
5.2.4 Doppler Shifts for Reflections
5.2.5 Doppler Effect on Wave Power*
5.2.6 Relativistic Doppler Effect*
5.3 Supersonic Motion
5.3.1 Explanation
5.3.2 Equations for Supersonic Motion*
5.4 Summary
5.5 Exercises
6 Mechanical Waves
6.1 Pendulums
6.1.1 How Pendulums Work
6.1.2 Momentum
6.2 String Waves
6.2.1 How String Waves Work
6.2.2 Speed of String Waves
6.3 Sound Waves
6.3.1 How Sound Waves Work
6.3.2 The Speed of Sound
6.3.3 The Sound Spectrum*
6.3.4 Sonar and Medical Ultrasound*
6.4 The Physics of Music*
6.4.1 Physics Terminology for Music*
6.4.2 The Western Musical Scale*
6.4.3 Musical Intervals*
6.4.4 Major, Minor, and Non-Western Musical Scales*
6.4.5 Musical Instruments*
6.5 Water Waves
6.5.1 Capillary Waves
6.5.2 Gravity Waves
6.5.3 Phase Velocity and Group Velocity
6.5.4 Water Motion in Waves
6.5.5 Water Wave Evolution*
6.5.6 Long Wavelength Water Waves: Tsunamis, Tides, and Seiches*
6.6 Seismic Waves*
6.6.1 The Earth's Structure*
6.6.2 Earthquakes*
6.6.3 Seismic Waves*
6.7 Summary
6.8 Exercises
Part IIRays
7 Shadows and Pinhole Cameras
7.1 Shadows
7.1.1 Projection
7.1.2 Analyzing Projections*
7.1.3 Umbra and Penumbra
7.2 Eclipses
7.2.1 Solar Eclipses
7.2.2 Lunar Eclipses
7.2.3 Eclipses and Moon Phases
7.3 Light Through Small Holes
7.3.1 Pinhole Cameras and Camera Obscuras
7.3.2 Pinhole Camera Analysis
7.3.3 Multiple Pinholes*
7.4 Shadow-Based Vision*
7.5 Summary
7.6 Exercises
8 Reflection
8.1 Reflection in General
8.1.1 Why Waves Reflect
8.1.2 Requirements for Mirrors
8.2 Plane Mirrors
8.2.1 Law of Reflection
8.2.2 Corner-Cube Retroreflectors
8.2.3 Images for Plane Mirrors
8.2.4 Size of a Mirror
8.3 Concave Reflectors
8.3.1 Parabolic Reflectors
8.3.2 Concave Spherical Mirrors
8.3.3 Concave Mirror Ray Diagrams
8.3.4 Mirror Equations
8.3.5 Spherical Aberration and Coma*
8.4 Convex Spherical Mirrors
8.5 Multiple Mirrors*
8.6 Mirrors, Inversion, and Symmetry*
8.7 Fermat's Principle of Least Time*
8.8 Summary
8.9 Exercises
Exercises
9 Refraction
9.1 Refraction in General
9.1.1 Refractive Index
9.1.2 Why Waves Refract
9.1.3 Refraction From Density Gradients
9.2 Refraction at Interfaces
9.2.1 Snell's Law
9.2.2 Apparent Depth
9.2.3 Refraction and Reflection at Different Angles
9.2.4 Total Internal Reflection Examples*
9.2.5 How Much Light Gets Reflected*
9.2.6 Evanescent Waves*
9.3 Lenses
9.3.1 Types of Lenses
9.3.2 Lens Coordinates
9.3.3 Images From Lenses
9.3.4 Lens Equations
9.3.5 Cameras*
9.3.6 Vision Correction*
9.4 Multiple Lens Systems*
9.4.1 Objects and Images*
9.4.2 Microscopes*
9.4.3 Telescopes*
9.4.4 More Optical Systems*
9.4.5 Electron Microscopes*
9.5 Dispersion
9.5.1 Prisms
9.5.2 Achromatic Lenses*
9.5.3 Rainbows*
9.6 Fermat's Principle of Least Time*
9.7 Summary
9.8 Exercises
Part IIILight
10 Color
10.1 Color Vision
10.1.1 How Vision Works
10.1.2 Light and Dark Adaptation
10.1.3 Different People see Different Colors*
10.1.4 Color Vision in Animals*
10.2 Color Models
10.2.1 Color Wheel
10.2.2 Light Addition with the RGB Color Model
10.2.3 Light Subtraction with the CMYK Color Model
10.2.4 Leaf Colors in Summer and Fall*
10.2.5 HSV Color Model
10.2.6 Color Spaces*
10.3 Summary
10.4 Exercises
11 Electromagnetic Waves
11.1 Light Waves as Electric and Magnetic Fields
11.1.1 Scalars, Vectors, and Fields
11.1.2 Electric Fields
11.1.3 Magnetic Fields
11.1.4 Changing Electric and Magnetic Fields
11.1.5 Electromagnetic Waves
11.1.6 How Electromagnetic Waves Work*
11.2 The Electromagnetic Spectrum
11.3 Scattering
11.3.1 Scattering Off Large Objects
11.3.2 Scattering Off Medium Size Objects
11.3.3 Scattering Off Small Objects
11.4 Polarization
11.4.1 Electromagnetic Wave Polarization
11.4.2 Polarizers
11.4.3 Multiple Polarizers
11.4.4 Liquid Crystal Displays
11.4.5 Sources of Polarized Light
11.4.6 Polarization as Superposition*
11.4.7 Birefringence and Optical Activity*
11.5 Summary
11.6 Exercises
12 Thermal Radiation
12.1 Thermal Radiation
12.1.1 Qualitative Trends
12.1.2 Blackbodies
12.1.3 Wien's Displacement Law
12.1.4 Color Temperature
12.1.5 Stefan-Boltzmann Law
12.1.6 Remote Temperature Measurement*
12.2 Thermal Radiation Interactions
12.2.1 Radiation Coupling and Emissivity
12.2.2 Two-Way Thermal Radiation
12.3 Earth's Climate*
12.3.1 Earth's Energy Budget*
12.3.2 Greenhouse Effects on Mars and Venus*
12.3.3 Global Warming*
12.4 Summary
12.5 Exercises
Part IVModern Physics
13 Photons
13.1 The Quantum Revolution
13.1.1 Explaining Blackbody Radiation
13.1.2 Particles and Waves
13.1.3 What is a Photon?
13.2 Photon Energy
13.2.1 Planck-Einstein Relation
13.2.2 Photoelectric Effect
13.2.3 Photoelectric Effect Examples*
13.2.4 Photochemistry*
13.2.5 Compton Scattering
13.3 Photon Momentum
13.3.1 Classical Momentum
13.3.2 Photon Momentum
13.3.3 Radiometers*
13.3.4 Solar Sails*
13.3.5 Laser Tweezers*
13.3.6 Doppler Cooling*
13.4 Particle-Wave Duality
13.4.1 Quantum Interpretation of the Double-Slit Experiment
13.4.2 Photon Size*
13.4.3 Spectral Broadening of Pulses
13.4.4 Energy-Time Uncertainty
13.4.5 Particle-Wave Duality for Other Wave Types*
13.5 Summary
13.6 Exercises
14 Matter Waves
14.1 Matter Waves
14.1.1 De Broglie Relations
14.1.2 Wave Functions
14.1.3 What is Waving?
14.2 Traveling Matter Waves
14.2.1 Free Particles
14.2.2 Classical and Quantum Roller Coasters
14.2.3 Barriers and Tunneling
14.2.4 Tunneling Examples*
14.3 Diffraction and Interference
14.3.1 Electron Diffraction
14.3.2 Diffraction for Research*
14.3.3 Interference to Test Quantum Mechanics*
14.4 Standing Matter Waves
14.4.1 Electrons in a Cavity
14.4.2 Filling in Electrons
14.4.3 Molecular Vibrations
14.4.4 Structures of Atoms
14.4.5 Chemical Bonds*
14.5 Energy Level Transitions
14.5.1 Light Absorption
14.5.2 Light Emission
14.5.3 Fluorescence
14.5.4 Phosphorescence*
14.5.5 Lasers
14.6 Quantum Weirdness
14.6.1 Heisenberg Uncertainty Principle
14.6.2 Schrödinger's Cat Experiment*
14.6.3 The EPR Paradox*
14.6.4 Quantum Decoherence*
14.6.5 Macroscopic Quantum Systems*
14.7 Summary
14.8 Exercises
15 Gravitational Waves
15.1 Gravity
15.1.1 Newtonian Gravity
15.1.2 Tides
15.1.3 Gravitational Fields
15.2 Gravitational Waves
15.2.1 First Direct Detection
15.2.2 What are Gravitational Waves?
15.2.3 Frequency
15.2.4 Polarization
15.2.5 Energy
15.2.6 Momentum
15.3 Propagating Gravity
15.3.1 Speed of Gravity
15.3.2 Gravitational Near and Far Field*
15.4 Warped Space
15.4.1 The Equivalence Principle
15.4.2 Gravitational Attraction of Light
15.4.3 Curved Space
15.4.4 Ripples in Spacetime
15.5 Gravitational Wave Detection
15.5.1 Existing Observatories
15.5.2 Future Observatories
15.6 Summary
15.7 Exercises
A Numbers
A.1 Scientific Notation
A.1.1 Scientific Notation on a Calculator
A.2 More Calculator Advice
A.3 Precision
A.3.1 Determining Precision in Calculations
A.3.2 Propagating Uncertainties
A.4 Exercises
B Units
B.1 Units Are Your Friends
B.2 The Metric System
B.3 Unit Math
B.4 Unit Conversion
B.5 Exercises
C Algebra
C.1 Solving Problems
C.2 Expressions and Equations
C.2.1 Manipulating Expressions
C.2.2 Manipulating Equations
C.3 Exponents
C.4 Exercises
D Geometry
D.1 Triangles
D.1.1 Similar Triangles
D.1.2 Right Triangles and Trigonometry
D.2 Perimeters, Areas, and Volumes
D.3 Exercises
E Additional Resources
F Answers to Odd-Numbered Problems
G Figure Credits
H Useful Facts and Figures
Index