Quantum Field Theory: Introduction

This lecture introduces Quantum Field Theory (QFT) as the only way to reconcile Quantum Mechanics with Relativity, emphasizing the need for a local field due to the impossibility of instantaneous interactions at a distance. The instructor discusses the classical Electrodynamics and the quantization of the Electromagnetic field, highlighting the transition from point particles to field particles. The lecture covers the Klein-Gordon equation, relativistic invariance, and the failure of point particle mechanics in the context of Relativity and Quantum Mechanics. It also explores the natural system of units and the importance of measuring phenomena in the correct units, focusing on energy units in particle physics.