This textbook introduces students to the tools of order-of-magnitude reasoning and scientific approximation. The course curriculum focuses on managing complexity by breaking it down (divide-and-conquer) and intentionally discarding information to find the essence of a system (easy cases and lumping). The ultimate goal is to build deep, intuitive physical insight that precedes and guides exact calculation.

Key Topics

• Invariants
• Proportional reasoning
• Dimensions
• Probabilistic reasoning
• Symmetry and conservation