The Architecture of Motion
Classical Mechanics in 22 chapters — from “Configuration Space and the Geometry of Motion” to “Stability Theory: Linearization, Floquet Theory, and Arnold Diffusion”.
Chapters
- Configuration Space and the Geometry of Motion
- Degrees of Freedom and Configuration Manifolds
- Generalised Coordinates and Constraint Surfaces
- Velocities as Tangent Vectors
- Time Derivatives in Generalised Coordinates
- Examples: Pendulum, Double Pendulum, Rigid Body
- Summary and forward view
- Problems
- Selected solutions
- Newton’s Laws and the Newtonian Program
- The Three Laws: Axioms and Their Domain
- Single-Particle Dynamics in Various Force Fields
- Systems of Particles: Internal and External Forces
- Constraints and Constraint Forces
- The Newtonian Program’s Limitations
- Summary and forward view
- Problems
- Selected solutions
- The Principle of Stationary Action
- The Action Functional and Hamilton’s Principle
- The Calculus of Variations: Deriving Euler-Lagrange
- From Lagrangian to Newton: The Special Case L=T−V
- Why Stationary, Not Minimum? The Role of Conjugate Points
- Historical Interlude: Maupertuis, Euler, and Lagrange
- Summary and forward view
- Problems
- Selected solutions
- Lagrangian Mechanics: Formalism and First Applications
- The Lagrangian in Generalized Coordinates
- Cyclic Coordinates and Conserved Momenta
- The Energy Function and When It Is Conserved
- Generalized Forces and Non-Conservative Systems
- Worked Examples
- Summary and forward view
- Problems
- Selected solutions
- Noether’s Theorem and the Deep Structure of Conservation
- Continuous Transformations and Infinitesimal Generators
- Noether’s Theorem: The Coordinate Proof
- Noether’s Theorem: The Geometric Interpretation
- The Ten Classical Conserved Quantities
- Historical Note: Noether’s 1918 Paper and Its Reception
- Summary and forward view
- Problems
- Selected solutions
- Rotational Kinematics: The Geometry of SO(3)
- Rotations as Active Transformations, and the Group SO(3)
- Euler's Rotation Theorem and the Axis-Angle Representation
- Infinitesimal Rotations and the Lie Algebra so(3)
- Angular Velocity and the Transport Theorem
- Euler Angles and the Gimbal Singularity
- The Topology of SO(3): Real Projective Space and the Plate Trick
- Summary and forward view
- Problems
- Selected solutions
- Rigid Body Dynamics I: Inertia Tensor and Euler’s Equations
- Kinematics of Rigid Bodies: Configuration Space SO(3)×R3
- The Inertia Tensor: Definition and Principal Axes
- Angular Momentum and Kinetic Energy in Body and Space Frames
- Euler’s Equations for Torque-Free Motion
- The Poinsot Construction and Geometric Visualization
- Stability of Rotation About Principal Axes
- Summary and forward view
- Problems
- Selected solutions
- Rigid Body Dynamics II: The Heavy Symmetric Top
- Euler Angles and the Kinetic Energy of a Symmetric Body
- The Lagrangian, the Cyclic Coordinates and the Two Conserved Momenta
- Reduction to One Dimension: The Effective Potential
- The Three Motions of the Axis: Loops, Cusps and Unidirectional Precession
- Steady Precession, Its Two Roots, and the Fast-Top Limit
- The Sleeping Top, and Where This Treatment Breaks Down
- Summary and forward view
- Problems
- Selected solutions
- Small Oscillations and the Eigenvalue Problem
- Equilibrium Points and Linearization
- The Eigenvalue Problem for Coupled Oscillators
- Normal Modes and Normal Coordinates
- Degeneracy, Symmetry, and Mode Selection
- Worked Examples
- Summary and forward view
- Problems
- Selected solutions
- Driven and Damped Oscillations: Resonance and Response
- Damping Mechanisms and the Damped Harmonic Oscillator
- Driven Oscillations and the Steady-State Response
- Transient Behaviour and the Green’s Function
- Coupled Driven Oscillators: Impedance and Mode Mixing
- Computational Exercise: Frequency Sweep and Resonance Curves
- Summary and forward view
- Problems
- Selected solutions
- Perturbation Theory and Secular Effects
- Time-Independent Perturbation Theory: Shifting a Normal Mode
- The Naive Expansion and the Birth of Secular Terms
- The Anharmonic Oscillator and the Poincaré-Lindstedt Method
- The Method of Multiple Scales
- Non-Conservative Perturbations: Where Damping Comes From, and the van der Pol Limit Cycle
- Slowly Varying Parameters and the Adiabatic Invariant
- Summary and forward view
- Problems
- Selected solutions
- The Hamiltonian Formulation: Phase Space and Canonical Equations
- The Legendre Transformation and Conjugate Momenta
- Hamilton's Equations and Phase Space
- Why Hamiltonian? Advantages Over the Lagrangian Formulation
- Poisson Brackets and the Algebra of Observables
- Three Worked Systems: Oscillator, Central Force, Charged Particle
- Summary and forward view
- Problems
- Selected solutions
- Symplectic Geometry and Liouville's Theorem
- The Form on Phase Space
- The Matrix J and the Symplectic Group
- The Poisson Bracket Was the Symplectic Form All Along
- Liouville's Theorem, Proved Twice
- The Poincaré Integral Invariants
- What Volume Conservation Forbids, and What It Forces
- Summary and forward view
- Selected solutions
- Canonical Transformations and Generating Functions
- The Freedom of Coordinates in Phase Space
- What Canonical Means: Two Definitions and Their Equivalence
- Generating Functions and the Four Types
- Four Transformations Worked Through
- Infinitesimal Canonical Transformations and Their Generators
- The Canonical Group
- Summary and forward view
- Problems
- Selected solutions
- Hamilton-Jacobi Theory: Action as a Function
- Hamilton's Principal Function and the H-J Equation
- The H-J Equation as a Canonical Transformation to Equilibrium
- Separation of Variables and Ignorable Coordinates
- Worked Example: The Kepler Problem in Spherical Coordinates
- Hamilton's Characteristic Function and Time-Independent Systems
- Connection to Quantum Mechanics: The Semiclassical Limit
- Summary and forward view
- Problems
- Selected solutions
- Integrability and the Liouville-Arnold Theorem
- Constants of Motion and Involution
- Complete Integrability: The Liouville Condition
- The Liouville-Arnold Theorem and Torus Foliation
- Action-Angle Variables: Definition and Construction
- Frequencies and the Frequency Map
- Summary and forward view
- Problems
- Selected solutions
- Central Force Motion and Orbital Mechanics
- Reduction to the One-Body Problem and Effective Potential
- The Orbit Equation and Kepler's First Law
- Kepler's Second and Third Laws from Conserved Quantities
- The Laplace-Runge-Lenz Vector and SO(4) Symmetry
- Action-Angle Variables for the Kepler Problem
- Perturbations and Orbital Precession
- Summary and forward view
- Problems
- Selected solutions
- The Three-Body Problem and the Onset of Chaos
- The Restricted Circular Three-Body Problem
- The Jacobi Integral and Zero-Velocity Curves
- The Five Lagrange Points and Their Stability
- Poincaré Sections and the Breakdown of Integrability
- Computational Exercise: Simulating the Three-Body Problem
- Summary and forward view
- Problems
- Selected solutions
- Perturbation Theory for Nearly Integrable Systems
- The Nearly Integrable Setting
- First-Order Canonical Perturbation Theory
- Secular and Oscillatory: The Averaging Principle
- Resonance and the Resonant Normal Form
- The Pendulum Approximation and the Resonance Width
- Small Divisors, Divergence, and Resonance Overlap
- Summary and forward view
- Problems
- Selected solutions
- KAM Theory and the Persistence of Invariant Tori
- The Question KAM Answers, and Why It Was Thought Hopeless
- Nondegeneracy, and What “Irrational Enough” Means
- The Theorem, and What It Does Not Say
- The Standard Map: A Laboratory for Torus Destruction
- The Last Torus: The Golden Ratio and Greene's Criterion
- Confinement in Two Degrees of Freedom, and Its Failure Above Two
- Summary and forward view
- Problems
- Selected solutions
- Chaos, Lyapunov Exponents, and Sensitive Dependence
- Sensitive Dependence and the Definition of Chaos
- Lyapunov Exponents: Definition and Computation
- The Lyapunov Spectrum for Higher-Dimensional Systems
- The Driven Pendulum and the Hénon-Heiles System
- A Computational Recipe
- Summary and forward view
- Problems
- Selected solutions
- Stability Theory: Linearization, Floquet Theory, and Arnold Diffusion
- What Stability Means, and the Several Things the Word Is Used For
- Linearisation About an Equilibrium
- Periodic Orbits, the Monodromy Matrix, and Floquet Multipliers
- Poincaré Sections and the Reduction to a Map
- Arnold Diffusion and the Nekhoroshev Estimate
- What Classical Mechanics Settled, and What It Left Open
- Summary and forward view
- Problems
- Selected solutions