Unearthing Fermi's Geophysics

Description

Follow Nobel laureate and legendary teacher Enrico Fermi’s lost course on geophysics. Nobel Prize–winning physicist Enrico Fermi (1901–54) is known for his work on experimental particle and nuclear physics, quantum theory, and statistical mechanics, and for his particular ability to condense complicated problems into approximations for understanding and testing theory in a variety of scientific disciplines. Six of his graduate students went on to win their own Nobel Prizes. Unearthing Fermi’s Geophysics opens a window onto two underrepresented facets of this extraordinary thinker: Fermi’s teaching and his contribution to the field of geophysics. Drawing on Fermi’s handwritten calculations and notes, many of which are reproduced here in photographic facsimile, physicists Gino Segrè and John Stack have reconstructed a coursebook of Fermi’s insights into the physics of a range of geological and atmospheric phenomena. From gravity on Earth to thermodynamics in the atmosphere, the physics of raindrops, the Coriolis effect in hurricanes, tidal physics, earthquakes and seismic waves, Earth’s magnetism, atmospheric electricity, and much more, Unearthing Fermi’s Geophysics reveals the hidden workings of the world above, around, and below us—and of the mind of a great scientist who was able to bring those physical workings to light. Contents Preface Acknowledgments 1. Introduction 1.1 Fermi’s Notes 1.2 Plan of the Book 2. Gravity and the Earth 2.1 The Earth’s Gravity 2.2 Earth’s Gravitational Potential 2.3 Pressure at the Center of the Earth 2.4 The Moments of Inertia of the Earth 2.5 Motions of the Earth’s Axis 2.6 Equinoxes and Solstices 2.7 Precession of the Equinoxes 2.8 Free Rotational Motion 3. Heat and the Atmosphere 3.1 First Law of Thermodynamics 3.2 State Variables 3.3 The Second Law of Thermodynamics 3.4 Ideal Gas 3.5 Chemical Potential 3.6 The Boundary between Phases 3.7 Moist Air 3.8 Atmospheric Composition and Temperature 3.9 Temperature vs. Altitude 3.10 The Upper Atmosphere 4. Atmospheric Loss 4.1 Maxwell Distribution 4.2 Escape Velocity 4.3 Lifetime of Atmosphere 4.4 Magnitude of Particle Losses 4.5 Helium 4.6 Speed of Sound 5. Liquid Drop Physics 5.1 Vapor Pressure and Raindrops 5.2 Liquid Drops Affect Vapor Pressure 5.3 Properties of Falling Raindrops 6. Coriolis Effects 6.1 The Coriolis Force 6.2 Coriolis Effects in the Atmosphere 6.3 Hurricanes 7. Radiation at the Surface 7.1 Surface of the Earth 7.2 Crust of the Earth 7.3 Composition of the Oceans 7.4 Surface Temperature Equilibrium 7.5 Black Body Radiation 7.6 Planck’s Formula 7.7 Special Cases 8. Ocean Properties 8.1 Heat Current 8.2 The Heat Equation 8.3 Diurnal Temperature Variation 8.4 Temperature of Seawater 8.5 Ocean Circulation 9. Gravity Waves 9.1 Dispersion Relations 9.2 Euler’s Equation 9.3 Small Amplitude Surface Waves 10. Tide Physics 10.1 Effects of the Moon 10.2 The Tidal Potential 10.3 Water-Covered Earth 10.4 Time Dependence of Tides 10.5 Tides on Lakes and Seas 11. Earthquake Properties 12. Seismic Waves 12.1 Elementary Seismographs 12.2 Seismic Waves 12.3 Strain and the Strain Tensor 12.4 Stress and the Stress Tensor 12.5 Hooke’s Law 12.6 Young’s Modulus and Poisson’s Ratio 12.7 Stress and Strain 12.8 Newton’s Law in a Solid 12.9 The Equation of Motion for Displacement 12.10 Longitudinal and Transverse 12.11 Snell’s Law for Elastic Waves 13. Surface Seismic Waves 13.1 Surface Waves 13.2 Oscillations of the Earth 13.3 Breather Mode 14. Radioactivity 14.1 Historical Note 14.2 The Sixth Washington Conference 14.3 The Earth’s Density 14.4 Estimates of the Age of the Earth 14.5 Radioactive Decay Equation 14.6 Radioactivity within the Earth 14.7 Uranium Decays 14.8 Radioactive Dating 15. Heat Flow in the Earth 15.1 Surface Heat Variations 15.2 Heat at the Earth’s Surface 15.3 Scales in Heat Conduction 15.4 Heat Equilibrium 16. Earth Magnetism 16.1 Units 16.2 Magnetic Moments 16.3 Magnetic Field of the Earth 16.4 Earth Magnetization 16.5 Rotation of Charges 16.6 Currents inside the Earth 16.7 Magnetosphere 16.8 Magnetic Storms 16.9 Magnetic Potential Expansion 17. Atmospheric Electricity 17.1 Overview 17.2 Properties of the Electrosphere 17.3 Water Drops in an Electric Field 18. Atmospheric Plasma 18.1 Ions in the High Atmosphere 18.2 Atmospheric Radio Waves 18.3 Other Effects 18.4 Double Refraction Afterword Appendix A. Earth Days Appendix B. Torque on the Earth Appendix C. Rayleigh Waves Bibliography Index