Dr. Carroll explains the subject of dark matter and dark energy in 24 lectures. He explains why scientists believe we live in a smooth, expanding universe that originated in a hot, dense state called the Big Bang. He describes the features of the infant universe that led to the large-scale structure we observe today. He takes you through the standard model of particle physics and shows how it provides the framework for understanding the interaction of all matter and radiation. And, he helps you understand why dark matter and dark energy are logical consequences of a wide range of scientific theories and observations and how together they complete a grand picture of the universe that has emerged over the last century.