I'm wondering if causality is enough to derive the Minkowski metric and the Lorentz transformations. It seems to me that in order to ensure that some set of events maintain a causal relationship to each other under a transformation to a moving frame of reference, that there must be some restrictions on the metric in such a space and on the types of transformations of reference frames allowed in that space. Otherwise you could transform to some ref frame in which the causality is reversed. So is it a well established part of relativity that the Minkowski metric and/or the Lorentz transformations are derived solely from causality? If not, is there anyone working on this effort? Thanks.