EVIDENCE FOR AND AGAINST THE MULTIVERSE, OR, WHERE IS PHYSICS GOING?
Abstract: We will review the physical evidence for the Big Bang and point out that it leads to questions such as the horizon problem, the flatness problem, and the unexplained absence of magnetic monopoles arising from grand unification. These “accidents” can be very naturally explained if an inflationary epoch, in which the universe expanded exponentially, preceded the familiar Big Bang. Inflation also makes further predictions, which are supported by observations. An inescapable consequence of inflation in a flat, unbounded space is that infinitely many other universes with which we cannot interact must exist. Everett’s interpretation of the wave function and the measurement process is another and seemingly unrelated route to the idea of a multiverse. All this requires a re-examination of Popper’s famous falsifiability criterion. We will provide a sampling of different responses to these ideas by leading scientists.
Reminder: Tea and cookies will be in the seminar room before the seminar.