Reviews of the book consistently highlight the "not-so-easy" nature of its content compared to the first volume:
Richard Feynman's is a collection of six lectures curated from his legendary Feynman Lectures on Physics . While its predecessor, Six Easy Pieces , covers fundamental concepts like atoms and energy, this sequel dives into the more complex and revolutionary side of 20th-century physics: Relativity . Core Concepts Covered
: This central portion explains how the flow of time and mass change with velocity, and why the speed of light remains constant for all observers.