Presented in A. Zee’s incomparably engaging style, this book introduces physics students to the practice of using physical reasoning and judicious guesses to get at the crux of a problem. An essential primer for advanced undergraduates and beyond, *Fly by Night Physics* reveals the simple and effective techniques that researchers use to think through a problem to its solution—or failing that, to smartly guess the answer—before starting any calculations.

In typical physics classrooms, students seek to master an enormous toolbox of mathematical methods, which are necessary to do the precise calculations used in physics. Consequently, students often develop the unfortunate impression that physics consists of well-defined problems that can be solved with tightly reasoned and logical steps. Idealized textbook exercises and homework problems reinforce this erroneous impression. As a result, even the best students can find themselves completely unprepared for the challenges of doing actual research.

In reality, physics is replete with back of the envelope estimates, order of magnitude guesses, and fly by night leaps of logic. Including exciting problems related to cutting-edge topics in physics, from Hawking radiation to gravity waves, this indispensable book will help students more deeply understand the equations they have learned and develop the confidence to start flying by night to arrive at the answers they seek. For instructors, a solutions manual is available upon request.

**A. Zee** is professor of physics at the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara. His many books include *On Gravity*, *Group Theory in a Nutshell for Physicists*, *Einstein Gravity in a Nutshell*, *Quantum Field Theory in a Nutshell*, and *Fearful Symmetry* (all Princeton).

- Preface
- Dimensions and fundamental constants
- I Dimensional analysis: from a not so secret to an allegedly secret weapon
- 1. Dimensional analysis: a not so secret weapon
- 2. From Kepler’s law to black holes
- 3. Bohr’s atom and Heisenberg’s uncertainty principle: opposition and compromise
- 4. The dull function hypothesis
- 5. Match wits with Einstein over diffusion and dissipation
- 6. Energy released in the first atomic bomb test
- Interlude: Math medley 1

- II Telecommunication is possible
- 1. Electromagnetism: strange dimensions
- 2. The emission of electromagnetic waves
- 3. Electromagnetic radiation from moving point charges and Compton scattering
- 4. Relativistic effects by promotion and completion

- III Quantum physics: tunneling in stars, scaling, atoms, and black holes
- 1. From drawing the Schrödinger wave function to tunneling in stars
- 2. Scaling and the importance of being clean
- 3. The Landau problem in quantum mechanics
- 4. Atomic physics
- 5. Black body radiation
- A word of encouragement to the reader: on getting confused by physics

- IV Planck gave us units: black hole radiation and Einstein gravity
- 1. Planck gave us God-given units
- 2. A box of photons and the power of natural units
- 3. Black holes have entropy: Hawking radiation
- 4. When Einstein gravity meets the quantum
- Interlude: Math medley 2

- V From ideal gas to Einstein condensation
- 1. Ideal Boltzmann gas
- 2. Van der Waals: master of the envelope
- 3. Quantum gases
- 4. Guessing the Fermi-Dirac distribution
- 5. Einstein condensation

- VI Symmetry and superb theorems
- Prologue to Part VI
- 1. Symmetry, fearful or fearless
- 2. Galileo, viscosity, and time reversal invariance
- 3. Newton’s two superb theorems: where is hell?

- VII Stars, black holes, the universe, and gravity waves
- 1. Stars
- 2. Collapse into black holes
- 3. The expanding universe
- 4. Power radiated in gravity waves
- Interlude: Math medley

- VIII From surfing to tsunamis, from dripping faucets to mammalian lungs
- 1. Water waves
- 2. A physicist at the seashore
- 3. Surface tension and ripples
- 4. From dripping faucets to mammalian lungs and water striders
- 5. Drag, viscosity, and Reynolds number

- IX From private neutrinos to charm
- Prologue to Part IX
- 1. A lightning introduction to particle physics and quantum field theory
- 2. Weak interaction: a few basic facts
- 3. Private neutrinos
- 4. Strangeness and charm

- Appendices
- Cp: Critical points
- Del: Delta function
- Eg: Einstein gravity: a lightning review
- ENS: From Euler to Navier and Stokes
- FSW: Finite square well
- Gal: Galilean invariance and fluid flow
- Gr: Green functions
- Grp: Group versus phase velocity
- L: Radial part of the Laplacian
- M: Maxwell’s equations: a brief review
- N: Newton’s two superb theorems and the second square root alert
- VdW: Fly by day derivation of van der Waals’s law from first principles

- Timeline
- Solutions to selected exercises
- Suggested reading
- Index

"This profound, subversive, and inspiring book teaches a style of thinking and problem-solving that leads to the kind of intuition that is often sorely missing in the traditional path through the physics curriculum. Those who know Zee's other creative and insightful works will be delighted to find that, simply put, Zee has done it again."—Rob Phillips, California Institute of Technology

"From the self-deprecating wit that sparkles on almost every page, to the breadth of topics, to the polished avoidance of rigor mortis, this book will bring you joy. Every physicist and advanced student of physics will find seams of gold here."—Sanjoy Mahajan, author of *Street-Fighting Mathematics: The Art of Educated Guessing and Opportunistic Problem Solving*

"A terrifically witty and well-written book that belongs on every physicist's shelf. A course based on fly by night physics should be offered in the curriculum of every physics department, and this book is an excellent textbook for such a course."—Grzegorz M. Madejski, SLAC National Accelerator Laboratory and Stanford University

"The book is stated to be intended for advanced undergraduates, but an audience just as appropriate would be physics instructors—anyone teaching electromagnetism, quantum and statistical mechanics, or particle physics who wants to convey the power and joy of exercising one's physical intuition."—Eugene Chiang, University of California, Berkeley

"*Fly by Night Physics* is a delightful romp through a remarkable range of fascinating physics topics, using straightforward tools and intuition to understand problems without deriving or relying on complicated equations."—Lawrence Weinstein, author of *Guesstimation 2.0: Solving Today's Problems on the Back of a Napkin*

"*Fly by Night Physics* contains a lot of wisdom, and lots of examples."—Francis Nimmo, University of California, Santa Cruz