Hi mhrt,
welcome to PhysicsOverflow and thanks for your nice contributions.
I hope you dont mind that I have associated your first question and severel comments that you have written while not loged in with your registered account, such that you can better access and edit them etc...
In case you forget to log in, you can ask me personally or request your unregistered contributions to be associated with your account here
http://www.physicsoverflow.org/36103/claims-of-unregistered-contributions?show=36103#q36103
Best wishes
Dilaton