Explore the fascinating concept of the multiverse in this 29-minute video lecture by Sean Carroll. Delve into the scientific validity of multiverse theory, examining its origins in the big bang and its relationship to the arrow of time. Learn about hypothetical universes, the anthropic principle, vacuum energy, and the role of inflation and quantum mechanics in multiverse theory. Discover how string theory explains space-time and address potential problems with the multiverse hypothesis. Investigate the use of dark matter in making predictions and the measure problem associated with multiverse theory. Gain insight into why scientists consider the multiverse and how to approach this complex idea moving forward.