Is There a String Theory Landscape: Some Cautionary Notes

There is evidence that string theory possesses a large discretuum of stable and/or metastable ground states, with zero or four supersymmetries in four dimensions. I discuss critically the nature of this evidence. Assuming this "landscape" exists, anthropic explanations of some quantities are almost inevitable. I explain that this landscape is likely to lead to a prediction of low energy supersymmetry. But we argue that many features of low energy physics are not anthropic and, as currently understood, the landscape picture will get them wrong. This indicates that this viewpoint is potentially falsifiable. Moreover, if it is correct, many questions must be answered through more conventional scientific explanations. This is based on talks presented at the conference QTS3 at the University of Cincinnati and at the ITP in 2003.