Part 3/10:
Quantum field theory revolutionizes our understanding of elementary particles. While traditional approaches viewed particles as standalone entities, QFT posits that each type of fundamental particle is an excitation of a corresponding field that permeates space. This means that electrons, photons, and other particles are manifestations of unique oscillations in their respective fields.
The Transition from Classical to Quantum Mechanics
The journey to understanding QED began with classical mechanics and evolved through the principles of quantum mechanics. However, traditional quantum mechanics, particularly Schrödinger's equation, often failed to fully capture the behavior of particles at relativistic speeds or in situations requiring the creation and annihilation of particles.