Part 4/10:
The concept of entropy is tied to thermodynamics and, by extension, the Second Law. These are statistical in nature, leading many to question their fundamental status. To grasp their foundation, we must explore the underlying features of nature from which these definitions of entropy emerge.
One critical perspective comes from quantum mechanics, where von Neumann entropy—applicable to quantum systems—provides a deeper understanding of entropy and its implications for the Second Law, the arrow of time, and the journey from quantum systems to classical reality.