Mini Physics
Part of Mini EducationSwitch subject

IPhO Modern Physics

IPhO modern physics hub: special relativity tools, quantum reasoning, and nuclear fundamentals for olympiad-style questions.

  • International Physics Olympiad preparation
  • 6 lessons
Start topic

Before you begin

Modern physics in IPhO is less about memorising extra facts and more about using a small set of constraints quickly: invariants in relativity, quantisation rules and energy-scale reasoning.

Be comfortable with: special relativity at H3, A-Level quantum physics and nuclear physics, and the IPhO problem-solving framework.

Learning goals
  • Apply modern physics models and problem-solving methods in competition settings.

Lessons

Work through them in order.

Build the bridge

  1. Special Relativity Toolkit (IPhO)Use invariants and a good choice of frame to solve relativity problems and check them quickly.
  2. Quantum Tools: Order of Magnitude (IPhO)Estimate quantum length and energy scales with the uncertainty principle instead of detailed algebra.

Build the official core

  1. Atomic Spectra: Models & Estimates (IPhO Modern)Use the hydrogen-like model, scaling with Z and quick wavelength conversions to estimate atomic spectra.
  2. Nuclear Decay & Binding Energy (IPhO Modern)Calculate Q-values, recoil sharing, binding energies and decay activity for nuclear problems.

Transfer to unfamiliar problems

  1. Relativistic Collisions & Invariants (IPhO SR)Solve relativistic collisions with four-momentum conservation, invariant mass and threshold conditions.
  2. Quantum Wells & Tunneling Toolkit (IPhO Quantum)Match wavefunctions at boundaries, use parity and estimate tunnelling through one-dimensional barriers.

Practise and check

Recommended nextModern Physics topic check

Topic reference

What you should be able to do

  • Select a frame or invariant in relativity and verify the non-relativistic limit where appropriate.
  • Estimate the controlling quantum length and energy scales before choosing a detailed model.
  • Apply conservation laws and quantisation ideas to atomic and nuclear processes with consistent units and signs.

Official scope: Stages selected official relativity, quantum, atomic and nuclear content while keeping specialised calculation techniques in later lessons.

Training habits

  • After solving, check the non-relativistic limit (v ≪ c) and the units.
  • For quantum problems, estimate the relevant length or energy scale first.