Of course, they do something. A Ph.D. is a prerequisite for any tenure-track faculty position. Post-doctoral training has become a de facto requirement for getting a faculty position in the sciences and engineering. Both provide you a strong background in doing research. These are important for becoming a professor. But what does a professor do all day? Well, what I have discovered as a new tenure-track assistant professor is that I do the following (in no particular order of importance or time investment):
- Attend committee and faculty meetings
- Meet with interested undergraduate and graduate students
- Prepare for and teach classes
- Write grants
- Advise my own graduate students
- Balance my lab budget
I am fortunate in many ways -- my Ph.D. and post-doc advisors gave me ample opportunities to write grants, mentor students, critique manuscripts -- so those aspects of my new job are not entirely mysterious to me. But in other ways, I was totally unprepared for being a professor -- I have very little teaching experience, no management experience, and I do not have the intrinsic talent for navigating the tricky political waters of the university and academia at large. But I am learning.
Since I can't do it over again, the best I can do is offer advice to graduate students and post-docs out there. It is easy to keep your head down and focus on just your own research, but if you are serious about getting a faculty position, and want to be as prepared as possible for when you start (and even then you will still be woefully unprepared), I would take every opportunity you can find to participate in research-related activities separate from doing research, and to try and teach at least part of a course, if not two or three courses. You will be glad you did -- and if you find you really dislike all these seemingly ancillary activities, then perhaps being a professor is not the profession for you.
P.S. If anyone has any suggestions for Q, I am in need of some help :)