Introduction to Electromagnetism

This lecture introduces the interaction between electromagnetic waves and matter, focusing on the behavior of molecules made of charged particles when exposed to incoming electromagnetic waves. It explains the simplification of this interaction at atomic scales, emphasizing the strong cohesion forces between particles. The classical mechanics approach to the two-bodies problem is discussed, leading to the quantum mechanics approach and band theory at the atomic scale. The transition from classical to quantum models is explored, highlighting the significance of probability distributions and energy states in understanding light-matter interactions.