Inflationary Cosmology: Is Our Universe part of a Multiverse?

Inflationary cosmology gives a plausible explanation for many observed features of the universe, including its uniformity, its mass density, and the patterns of the ripples that are observed in the cosmic microwave background. Beyond what we can observe, most versions of inflation imply that our universe is not unique, but is part of a possibly infinite multiverse. The speaker describes the workings of inflation, the evidence for inflation, and why he believes that the possibility of a multiverse should be taken seriously.