01
Why fields, not particles
What goes wrong if I insist on a wavefunction for one relativistic particle?
VideoFree
Quantum Fields: The Real Building Blocks of the Universe ↗David Tong · The Royal Institution
Frontier · Module 16
Quantum Field Theory
The deepest layer of established physics: reconcile quantum mechanics with special relativity and particles stop being fundamental. Fields are, and particles are what excitations of fields look like to a detector.
By the end of this module
You can explain what a particle is in the theory that replaced particles.
0%0 / 6 complete
02
Canonical quantization and the scalar field
How do I quantize something with infinitely many degrees of freedom?
ReadingFree
Quantum Field Theory — lecture notes ↗David Tong, Cambridge
Widely regarded as the best free QFT notes in existence.
03
The Dirac field and antimatter
What did Dirac do to the wave equation to make it relativistic?
Primary source★ LandmarkFree
The Quantum Theory of the Electron ↗Paul Dirac, 1928
Spin and antimatter arrive uninvited.
04
QED, Feynman diagrams and renormalization
Why do the infinities cancel, and is that legitimate?
Reading★ LandmarkFree
QED: The Strange Theory of Light and Matter — lecture recordings ↗Richard Feynman, University of Auckland
Feynman explaining QED to a general audience with no mathematics. Free video archive.
05
Path integrals
Can I reformulate all of quantum mechanics as a sum over histories?
Primary source★ LandmarkFree
Space-Time Approach to Non-Relativistic Quantum Mechanics ↗Richard Feynman, Rev. Mod. Phys. 1948
Check yourself
End-of-module quiz
Every answer comes with the reasoning, not just a verdict. Getting one wrong and reading why is the point.
01In quantum field theory, a particle is:
02Renormalization is best understood as:
03Antimatter appears in Dirac's theory because:
Answer all 3 to finish the module.