What if everything around you — every atom, every object, even you — once existed as pure light? In tonight’s Sleep Science Story, we explore one of the most mind-bending truths in physics: light can become matter, and matter can turn back into light. Relax as we dive into the strange world of E=mc², particle creation, and the dance between energy and mass that shapes our universe. From the heart of stars to the vacuum of space, discover how the cosmos continuously transforms light into life.