Study of the string theory landscape seems now to have become the hot research topic that one should be working on in order to be taken seriously as a cutting-edge researcher in particle theory. Last week there was a workshop at Trieste on String Vacua and the Landscape that drew many researchers. Some of the talks from the workshop are available on-line.
Following on the heel’s of Susskind’s popular book promoting the landscape, which has received excellent reviews from particle and string theorists, there’s a new one on the same topic coming out later this month from cosmologist Alex Vilenkin, entitled Many Worlds in One: The Search for other Universes.
As string theorists in search of something to write papers about pour into the landscape, with its more than 10500 possible hot research topics to work on, Sean Carroll reports from a cosmology workshop at the Perimeter Institute that trouble may be ahead for the subject. Sean gives a short summary of the talks at the workshop, in the majority of cases ending with “Made fun of the landscape”, or “Made fun of the anthropic principle”.
The main argument for the landscape mania has always been that it justifies Weinberg’s “prediction” of the size of the cosmological constant. I’ve written elsewhere about why this is not a legitimate scientific prediction, and is off by at least an order of magnitude anyway. Evidently Steinhardt and Turok are about to put out a paper claiming that the situation is much worse than this, that if you take anthropic reasoning seriously, the natural “prediction” of the landscape is that:
the cosmological constant should be quite large (many times the matter density, although presumably not at the Planck scale), and we should live in a single lonely galaxy in an empty universe dominated by vacuum energy.
It will be interesting to see if landscapeologists will be willing to admit that the only supposed “prediction” of this subject doesn’t work at all, and that it is not only pseudo-science, but failed pseudo-science.