The Quantum Divide Why Schrödinger's Cat is Either Dead Or Alive

We describe, and provide the quantum mechanical explanation of, a number of well-chosen illustrative modern (mostly optical) experiments that highlight the strange world of the quantum. The view of the world offered by quantum mechanics is shown to be counterintuitive and strikingly at odds with the common sense view of the world of everyday life and classical physics. We address in what sense these different points of view can be reconciled.