Special Relativity

Get up to (light) speed on Einstein's theory of relativity.

Relative Motion of Observers

Propagation of Light

The Mystery of the Luminiferous Aether

Einstein's Postulates

Derive: Lorentz Transformations

Length Contraction & Time Dilation

Relativistic Laser Tag

Cosmic Ray Muons

Spacetime Intervals and Causality

Chimp Twin Paradox

Rotations in Spacetime

Plight of the ABC Jungle Fruit

Superluminal Observations

UFO Encounter


Energy-Momentum Conservation

High-Energy Particles


Course description

This course was written in collaboration with Aaron Miller, a PhD in physics from Penn State University, and was integrated into a YouTube video series on MinutePhysics. Beginning with famous thought experiments and a few intuitive principles from Newtonian mechanics, this course closely follows Einstein's arguments leading to the epiphany that time and space are a single entity, spacetime, where physical processes unfold. After gaining experience with the mathematical machinery of relativistic physics, you will open the door to high-energy phenomena and Einstein's famous relationship, E = mc². In the end this course will boost you to the cusp of the most elegant of physical theories: general relativity.

Topics covered

  • 4-vectors
  • Lorentz Transformations
  • Mass-energy Equivalence
  • Spacetime Paradoxes
  • Particle Physics
  • Reference Frames
  • Spacetime Curvature
  • Spacetime Diagrams
  • Spacetime Intervals
  • Time Dilation

Prerequisites and next steps

You’ll need a fundamental understanding of Newtonian mechanics.


  • Classical Mechanics