If you were getting a PhD in either pure math or physics, with the intention of becoming a professor, does one first need to get a masters degree before their PhD, is it different for the two fields?
Um, no. The ERASMUS program is for undergraduate student exchange among universities in the EU. (which I am currently taking part inEurope has something called the "erasmus system", at least in most EU countries. It goes like this
Bachelors - 3 years
Masters - 2 years
PhD - 3 years