Talk:Poincare group

I tried to clarify the introduction to make it a little more intuitive what the Poincare group is, by comparing to the isometry group of R^3. Do revert me if I've made matters worse. I also corrected the claim that there are ten elements in the Poincare group: any composition of these things is also an element, so the group is infinite (indeed, just the set of all translations is infinite). What's really going on is that it's a 10-dimensional Lie group and the given 10 elements generate the associated Lie algebra. I don't want to say this in the article, but what's there now is a bit more precise. Additionally, I put in a section at the end which concisely states what the group is, aimed at the more mathematically inclined. --MarkGall 18:31, 7 August 2009 (EDT)