Alan Guth, Victor F. Weisskopf Professor of Physics and MacVicar Faculty Fellow, MIT
Inflationary cosmology gives a very plausible explanation for many features of our universe, including its uniformity, its mass density, and the patterns of the ripples that are observed in the cosmic microwave background. I will explain the basics of how inflation works, and how it leads to these successful predictions. An interesting feature of inflation is that almost all versions of it lead to eternal inflation: once inflation starts, it goes on forever, producing a "multiverse" of "pocket universes," one of which would be our universe. The multiverse idea is speculative, but I will explain why I believe it should be taken seriously.