Contents -- Preface -- Overview -- 1. Probability: Basic concepts and theorems -- 1.1 The principle of indifference -- 1.2 Subjective probabilities versus objective probabilities -- 1.3 Relative frequencies -- 1.4 Adding and multiplying probabilities -- 1.5 Conditional probabilities and correlations -- 1.6 Expectation value and standard deviation -- 2. A (very) brief history of the \old" theory -- 2.1 Planck -- 2.2 Rutherford -- 2.3 Bohr -- 2.4 de Broglie -- 3. Mathematical interlude -- 3.1 Vectors -- 3.2 Definite integrals -- 3.3 Derivatives -- 3.4 Taylor series -- 3.5 Exponential function -- 3.6 Sine and cosine -- 3.7 Integrals -- 3.8 Complex numbers -- 4. A (very) brief history of the "new" theory -- 4.1 Schrodinger -- 4.2 Born -- 4.3 Heisenberg and "uncertainty" -- 4.4 Why energy is quantized -- 5. The Feynman route to Schr odinger (stage 1) -- 5.1 The rules of the game -- 5.2 Two slits -- 5.2.1 Why product? -- 5.2.2 Why inverse proportional to BA? -- 5.2.3 Why proportional to BA? -- 5.3 Interference -- 5.3.1 Limits to the visibility of interference fringes -- 5.4 The propagator as a path integral -- 5.5 The time-dependent propagator -- 5.6 A free particle -- 5.7 A free and stable particle -- 6. Special relativity in a nutshell -- 6.1 The principle of relativity -- 6.2 Lorentz transformations: General form -- 6.3 Composition of velocities -- 6.4 The case against positive K -- 6.5 An invariant speed -- 6.6 Proper time -- 6.7 The meaning of mass -- 6.8 The case against K = 0 -- 6.9 Lorentz transformations: Some implications -- 6.10 4-vectors -- 7. The Feynman route to Schr odinger (stage 2) -- 7.1 Action -- 7.2 How to inuence a stable particle? -- 7.3 Enter the wave function -- 7.4 The Schrodinger equation -- A Closer Look -- 8. Why quantum mechanics? -- 8.1 The classical probability calculus -- 8.2 Why nontrivial probabilities?.

8.3 Upgrading from classical to quantum -- 8.4 Vector spaces -- 8.4.1 Why complex numbers? -- 8.4.2 Subspaces and projectors -- 8.4.3 Commuting and non-commuting projectors -- 8.5 Compatible and incompatible elementary tests -- 8.6 Noncontextuality -- 8.7 The core postulates -- 8.8 The trace rule -- 8.9 Self-adjoint operators and the spectral theorem -- 8.10 Pure states and mixed states -- 8.11 How probabilities depend on measurement outcomes -- 8.12 How probabilities depend on the times of measurements -- 8.12.1 Unitary operators -- 8.12.2 Continuous variables -- 8.13 The rules of the game derived at last -- 9. The classical forces: Effects -- 9.1 The principle of "least" action -- 9.2 Geodesic equations for at spacetime -- 9.3 Energy and momentum -- 9.4 Vector analysis: Some basic concepts -- 9.4.1 Curl and Stokes's theorem -- 9.4.2 Divergence and Gauss's theorem -- 9.5 The Lorentz force -- 9.5.1 How the electromagnetic field bends geodesics -- 9.6 Curved spacetime -- 9.6.1 Geodesic equations for curved spacetime -- 9.6.2 Raising and lowering indices -- 9.6.3 Curvature -- 9.6.4 Parallel transport -- 9.7 Gravity -- 10. The classical forces: Causes -- 10.1 Gauge invariance -- 10.2 Fuzzy potentials -- 10.2.1 Lagrange function and Lagrange density -- 10.3 Maxwell's equations -- 10.3.1 Charge conservation -- 10.4 A fuzzy metric -- 10.4.1 Meaning of the curvature tensor -- 10.4.2 Cosmological constant -- 10.5 Einstein's equation -- 10.5.1 The energy-momentum tensor -- 10.6 Aharonov-Bohm effect -- 10.7 Fact and fiction in the world of classical physics -- 10.7.1 Retardation of effects and the invariant speed -- 11. Quantum mechanics resumed -- 11.1 The experiment of Elitzur and Vaidman -- 11.2 Observables -- 11.3 The continuous case -- 11.4 Commutators -- 11.5 The Heisenberg equation -- 11.6 Operators for energy and momentum -- 11.7 Angular momentum.

11.8 The hydrogen atom in brief -- 12. Spin -- 12.1 Spin 1/2 -- 12.1.1 Other bases -- 12.1.2 Rotations as 2 2 matrices -- 12.1.3 Pauli spin matrices -- 12.2 A Stern-Gerlach relay -- 12.3 Why spin? -- 12.4 Beyond hydrogen -- 12.5 Spin precession -- 12.6 The quantum Zeno effect -- 13. Composite systems -- 13.1 Bell's theorem: The simplest version -- 13.2 "Entangled" spins -- 13.2.1 The singlet state -- 13.3 Reduced density operator -- 13.4 Contextuality -- 13.5 The experiment of Greenberger, Horne, and Zeilinger -- 13.5.1 A game -- 13.5.2 A fail-safe strategy -- 13.6 Uses and abuses of counterfactual reasoning -- 13.7 The experiment of Englert, Scully, and Walther -- 13.7.1 The experiment with shutters closed -- 13.7.2 The experiment with shutters opened -- 13.7.3 Inuencing the past -- 13.8 Time-symmetric probability assignments -- 13.8.1 A three-hole experiment -- 14. Quantum statistics -- 14.1 Scattering billiard balls -- 14.2 Scattering particles -- 14.2.1 Indistinguishable macroscopic objects? -- 14.3 Symmetrization -- 14.4 Bosons are gregarious -- 14.5 Fermions are solitary -- 14.6 Quantum coins and quantum dice -- 14.7 Measuring Sirius -- 15. Relativistic particles -- 15.1 The Klein-Gordon equation -- 15.2 Antiparticles -- 15.3 The Dirac equation -- 15.4 The Euler-Lagrange equation -- 15.5 Noether's theorem -- 15.6 Scattering amplitudes -- 15.7 QED -- 15.8 A few words about renormalization -- 15.8.1 . . . and about Feynman diagrams -- 15.9 Beyond QED -- 15.9.1 QED revisited -- 15.9.2 Groups -- 15.9.3 Generalizing QED -- 15.9.4 QCD -- 15.9.5 Electroweak interactions -- 15.9.6 Higgs mechanism -- Making Sense -- 16. Pitfalls -- 16.1 Standard axioms: A critique -- 16.2 The principle of evolution -- 16.3 The eigenstate{eigenvalue link -- 17. Interpretational strategy -- 18. Spatial aspects of the quantum world.

18.1 The two-slit experiment revisited -- 18.1.1 Bohmian mechanics -- 18.1.2 The meaning of "both" -- 18.2 The importance of unperformed measurements -- 18.3 Spatial distinctions: Relative and contingent -- 18.4 The importance of detectors -- 18.4.1 A possible objection -- 18.5 Spatiotemporal distinctions: Not all the way down -- 18.6 The shapes of things -- 18.7 Space -- 19. The macroworld -- 20. Questions of substance -- 20.1 Particles -- 20.2 Scattering experiment revisited -- 20.3 How many constituents? -- 20.4 An ancient conundrum -- 20.5 A fundamental particle by itself -- 21. Manifestation -- 21.1 "Creation" in a nutshell -- 21.2 The coming into being of form -- 21.3 Bottom-up or top-down? -- 21.4 Whence the quantum-mechanical correlation laws? -- 21.5 How are "spooky actions at a distance" possible? -- 22. Why the laws of physics are just so -- 22.1 The stability of matter -- 22.2 Why quantum mechanics (summary) -- 22.3 Why special relativity (summary) -- 22.4 Why quantum mechanics (summary continued) -- 22.5 The classical or long-range forces -- 22.6 The nuclear or short-range forces -- 22.7 Fine tuning -- 23. Quanta and Vedanta -- 23.1 The central a rmation -- 23.2 The poises of creative consciousness -- Appendix A. Solutions to selected problems -- Bibliography -- Index.