I am curious about how the Anthropic Principal could in principal be used to constrain possible values for physical constants. It seems plausible to me that quite a few physical constants are constrained to be within a few orders of magnitude of measured values, but that is just a guess. I would much appreciate seeing some discussion about which physical constants are so constrained, and which are not, and why. Here is an example of the kind of discussion I am looking for. If the cosmological constant were much larger, galaxies, or even clusters of stars would not be able to form since the expansion of the universe would move far apart mass concentrations that would form separate stars. Therefore, when a supernova occurs producing many atom types, these atoms would not be able to form solid planets around a newly forming star. Therefore, there would be no warm planetary surfaces on which life could evolve.