The August issue of Scientific American has the multiverse on the cover, with a skeptical feature article on the topic by George F. R. Ellis, Does the Multiverse Really Exist?, which argues that heavily promoted multiverse research isn’t really testable and can’t explain much of anything. Vilenkin and Tegmark respond with The Case for Parallel Universes.
I just took a look at some of the earliest postings on this blog about the multiverse from as far back as seven years ago (e.g. here and here). Things haven’t changed at all. One might be tempted to criticize Scientific American for keeping this alive, but they just reflect the fact that this pseudo-science continues to have significant influence at the highest levels of the physics establishment. The Perimeter Institute recently ran a conference on Challenges for Early Universe Cosmology, which was dominated by multiverse mania. Unlike the case at SciAm, multiverse skepticism didn’t get prominent play at Perimeter.
Update: For those of you who just can’t get enough multiverse, the Sci-Fi film Another Earth opens Friday. Click on “Parallel Worlds” for an explanation of “the theoretical physics behind the film.”