I am reading something about [Kaluza Klein theories](http://en.wikipedia.org/wiki/Kaluza%E2%80%93Klein_theory) and compactification. I have some conceptual question:

(1) Why do we call the fifth scalar field $\Phi$ the dilation field? Is there any scaling property for that?

(2) What happens to this field after dimensional reduction?

Many thanks if you can provide me with further reading material! :)