The (non)science of the multiverse
The article Physics in the multiverse in the December issue of CERN Courier annoyed me. In my opinion the multiverse(s) of the type that Aurelian Barrau describes are not science.
Science owes its success in, and acceptance by, society to a delicate balance between theory and experiment, namely to the ability of scientists to make clear honestly on which experimental facts their claims of explaining natural phenomena are based. Beautiful mathematical structures are science in their own right, but declaring them physical reality just because of their beauty is unscientific, especially if the main motivation is the inability to make verifiable (or falsifiable) predictions.
The author lists the criteria that are generally accepted for some statements to be called scientific. Yet his post-modernist claim that these criteria can and should be adapted to the flights of fancy of theoreticians is wrong. The dangers of such an attitude must not be underestimated. What has recently come down to the public as books and articles about multiverses looks to me like an ideological brainwash and a sales campaign. Everyone is free to believe what they like but we must not allow this to be called science. Too often in the past, private world views based on fanciful extrapolations of scientific facts turned out wrong. This is not just bad for those who held these views: the damage done to the credibility of the scientific community at large may well exceed what these fellows can take responsibility for.
Peter Schmid, Salzburg.