I want to write a sentence like "physics (from ancient greek φύσις)". But I don't know how to typeset the character "ύ" properly. Also I am not sure, if it is a good idea simply to use math-mode here to typeset the greek letters. So, what's the best way to typeset the ancient greek word φύσις?
Edit: I should add that I just copied the word from wikipedia in this case, so the
babel solutions work very well since I can just copy the greek word into my latex source. But I don't know how I can insert those greek letters directly with my normal german keyboard layout.