Human
conception of the size and diversity of the universe has changed
dramatically throughout history. The existence
of other planets, stars, and galaxies was
once wild speculation. However, we now have observational evidence that the universe contains hundreds of billions
of galaxies, each with hundreds of billions of
stars. Is this all that there is? A nexus
of ideas from theoretical cosmology, quantum gravity, and string theory suggests that it isn't. Rather, these theories predict the existence of an enormous
diversity of regions, each of which could
rightfully be called a universe; these theories suggest that we inhabit a Multiverse. Perhaps most excitingly, this idea can be tested with observations of the
large-scale structure of the observable
universe. This talk will explore the idea of a Multiverse and the most recent constraints on its properties from cosmology.