For the second installment of our Spring Special Series, “Big History.” In this episode, we explore the nature of energy, the fundamental force that drives change from the Big Bang to human civilization. We explore energy as the capacity to do work, discuss the law of conservation, and unravel Einstein’s revelation that mass itself is concentrated energy. Learn how energy transforms through various forms, from kinetic and potential to thermal and electromagnetic, and discover the concept of energy rate density, which links higher energy flows to greater complexity (think hummingbirds versus redwoods and the human brain versus the sun). We also trace how energy mastery has powered humanity’s evolution, from the agricultural revolution to the industrial era and our current push toward sustainable solutions. Finally, we journey to the stars to examine stellar nucleosynthesis, the cosmic alchemy that forges the elements essential for life. Join us for a rigorous yet accessible exploration of how energy weaves the very fabric of Big History.