Introduction

• Another unresolved mystery of classical physics
• Albert Einstein’s “heuristic principle”
• The photon and its detection
• Light’s dual personality

We explore a second important case of quantization, this time in the form of light quanta, and learn how it provides an elegant interpretation of Max Planck’s blackbody radiation solution. We’ll also learn how the discovery of light’s particle nature can be traced back to the very experiment that proved it was a wave.

We’ll be formally introduced to Albert Einstein, and see how he revived a concept promoted fruitlessly by his esteemed predecessor, Isaac Newton. We’ll learn about the photon and its important physical properties, and discover why it evaded detection for so long despite its ubiquity.

Finally, we’ll begin to explore the first of the great logical inconsistencies of quantum physics, wave-particle duality, and see the extent to which physicists have come to grips with it more than a century after its discovery.