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Complete University Physics Study Guide

flowchart TD
A[Hub] --> B[Key Concepts]
A --> C[Core Principles]
A --> D[Practical Applications]
B --> E[Fundamental definitions]
C --> F[Design patterns]
D --> G[Real-world usage]

University physics is a cumulative discipline — each topic builds on the ones before it. Classical mechanics provides the mathematical framework that electromagnetism, quantum mechanics, and thermal physics all use. This hub page maps every resource on this site and shows you how they connect, so you can study efficiently and build understanding that compounds.

These notes follow the standard undergraduate physics curriculum: from Newtonian mechanics through Lagrangian and Hamiltonian formulations, into electrodynamics, statistical mechanics, quantum theory, solid state physics, and particle physics. Each section includes derivations, worked examples, problem sets, and common pitfalls.


Physics is deeply cumulative. The following order reflects the mathematical and conceptual dependencies between topics. Deviate from it only if your course requires it.

  1. Classical Mechanics — the mathematical language all other domains use (Lagrangians, Hamiltonians, variational principles)
  2. Linear Algebra and Multivariable Calculus — prerequisites for everything else (see Mathematics)
  1. Electromagnetism — builds directly on mechanics and vector calculus
  2. Thermal Physics — requires probability theory; connects to statistical mechanics
  3. Quantum Mechanics — requires linear algebra, differential equations, and classical mechanics

Tier 3 — Applications and Specialisations

Section titled “Tier 3 — Applications and Specialisations”
  1. Optics and Waves — applications of electromagnetism and wave theory
  2. Solid State Physics — applies quantum mechanics to crystalline systems
  3. Particle Physics and Cosmology — synthesises quantum mechanics, electromagnetism, and relativity
Classical Mechanics
├── Electromagnetism (vector calculus, mechanics)
│ ├── Optics and Waves (wave equations, Maxwell's equations)
│ └── Particle Physics (special relativity, fields)
├── Quantum Mechanics (Lagrangian/Hamiltonian formalism)
│ ├── Solid State Physics (band theory, phonons)
│ └── Particle Physics (Feynman diagrams, symmetries)
└── Thermal Physics (probability, statistical methods)
└── Solid State Physics (statistical mechanics of solids)

Classical mechanics is the foundation of all physics. It begins with Newton’s laws and builds through Lagrangian and Hamiltonian formulations to the variational principles that underpin modern physics.


Thermal physics bridges the macroscopic laws of thermodynamics with the microscopic behaviour of particles through statistical mechanics. It explains why heat flows, why entropy increases, and how phase transitions emerge from simple microscopic rules.


Electromagnetism unifies electricity, magnetism, and light into a single framework described by Maxwell’s equations. It is the most experimentally precise theory in physics and underpins all electrical engineering and optics.


Optics describes how light propagates, interferes, diffracts, and polarises. The wave nature of light connects directly to electromagnetism, while Fourier optics and coherence theory bridge into signal processing and quantum optics.

  • The Wave Equation — derivation and solutions in one, two, and three dimensions
  • Electromagnetic Waves — plane waves, polarisation, and energy flux
  • Interference — Young’s slit, thin films, and multiple-beam interference
  • Diffraction — single slit, diffraction gratings, and the Fraunhofer limit
  • Polarisation — Malus’ law, birefringence, and wave plates
  • Geometric Optics — ray tracing, mirrors, lenses, and optical instruments
  • Fourier Optics — spatial frequency filtering and the optical transfer function
  • Coherence — temporal and spatial coherence, mutual coherence functions
  • Lasers — stimulated emission, population inversion, and laser types

Quantum mechanics replaces the deterministic world of classical physics with probabilistic wave functions and operators. It governs atoms, molecules, semiconductors, and subatomic particles. The mathematical framework — Hilbert spaces, operators, and commutation relations — is the language of modern physics.


Solid state physics applies quantum mechanics and statistical mechanics to crystalline materials. It explains why some materials conduct electricity, others insulate, and others become superconductors at low temperatures.


Particle physics identifies the fundamental building blocks of matter and the forces between them. The Standard Model is the most successful theory in physics — its predictions match experiments to extraordinary precision. Cosmology extends physics to the universe as a whole.



Physics relies heavily on mathematical tools and connects to applied fields:

  • University Mathematics — linear algebra, differential equations, real analysis, and group theory: the mathematical foundations of physics
  • C++ Programming — computational physics, numerical methods, and scientific computing
  • IB Physics — introductory physics at the IB level, covering the same domains with less mathematical rigour
  • DSE Physics — secondary-level physics for the Hong Kong DSE

University physics problems require a systematic approach. Here is a framework that works across all domains.

Before writing equations, determine which physical principles apply. Is this a conservation of energy problem? Does it involve forces? Is it a boundary value problem? Classification before calculation prevents wasted effort.

Sketch the system. Label all quantities with symbols. Define your coordinate system. A clear diagram often reveals the solution path.

Start with general principles: Newton’s second law, Maxwell’s equations, the Schrödinger equation, or conservation laws. Substitute known values and identify what you need to find.

Work through the algebra in terms of symbols, not numbers. This reduces arithmetic errors and makes dimensional analysis possible at every step.

  • Dimensions — does the answer have the right units?
  • Limits — what happens when a parameter goes to zero or infinity?
  • Signs — does the direction make physical sense?
  • Symmetry — does the answer respect the symmetries of the problem?

Skipping the derivation and memorising the formula: Physics formulas are derived from principles. Memorising without understanding leads to wrong applications when conditions change.

Confusing precision with accuracy: High-precision calculations with wrong assumptions give precise but inaccurate results. Always check whether the model matches the physical situation.

Ignoring sig figs and unit consistency: Physics answers must have correct significant figures and consistent units. Dropping units mid-calculation leads to dimensional errors.


Where should I start if I am new to university physics?

Section titled “Where should I start if I am new to university physics?”

Begin with Classical Mechanics. Work through every section in order, including the problem sets. Classical mechanics teaches you the mathematical habits (Lagrangians, Hamiltonians, variational methods) that all other domains assume.

Attempt each problem before reading any solution. Spend at least 15 minutes on a problem before moving on. The problems are ordered by difficulty within each set — the early ones are straightforward applications, while the later ones require synthesis of multiple concepts.

At minimum: multivariable calculus (partial derivatives, multiple integrals, vector calculus), linear algebra (vectors, matrices, eigenvalues), and ordinary differential equations. For advanced topics: real analysis, group theory, and complex analysis. See the Mathematics study guide for detailed coverage.

Yes. Each section includes definitions, derivations, worked examples, and common pitfalls. Work through the examples with paper and pen — do not just read them. Then attempt the problem sets to test your understanding.

How do the advanced topics relate to the core topics?

Section titled “How do the advanced topics relate to the core topics?”

Advanced topics extend the core material. For example, nonlinear dynamics extends classical mechanics, quantum statistical mechanics extends both quantum mechanics and thermal physics, and topological insulators extend solid state physics. Study the core topics first — the advanced topics assume fluency with the foundational material.

Can I study quantum mechanics without completing classical mechanics first?

Section titled “Can I study quantum mechanics without completing classical mechanics first?”

You can, but you will miss the mathematical tools (Hamiltonian mechanics, Lagrangians, symplectic structure) that make quantum mechanics natural rather than arbitrary. The transition from classical to quantum is much smoother when you understand the Hamiltonian formulation.


Last updated: 24 July 2026

Written by Wyatt. For questions or feedback, visit wyattau.com.