I don't understand what you are saying is impossible about this. Are you just saying "try it and be really careful about it and you will see that it is impossi

I don't understand what you are saying is impossible about this. Are you just saying "try it and be really careful about it and you will see that it is impossible"? Because I don't see why that claim should be convincing without, saying why? (Maybe I missed some other comment of yours?)