Professors have three full time jobs; administrator, researcher (well supervision of people actually doing the research, but this is very time consuming if done right), and teaching. Each job is more than 35 hours a week (the time I was nominally paid for).
I was deliberately terrible at the administration side and outright refused to do anything unless it meant more money for my department (the one good thing about tenure is you can be a pain in the backside and not get fired), but even spending less than 10 hours a week on admin, my work week was rarely less than 80 to 90 hours.
One of the major reasons why I quit academia and went back to my startup was to have more time to spend with my family.
Can you explain why you made a point to say "supervise students"? From your statement it looks like there is no expectation to do original/independent research. Is that the standard practise too?
I didn't say supervise students so it was not a point I made??
I of course did supervise students. This does vary by field, but done right each student needs about 5 hours a week one-on-one direct enagagement (more at the beginning of their degree and less at the end). Less time than this and the student will struggle.
You can of course do what some of the big empire builders do and just let the student sink or swim on their own, but this is not good for the student. Good supervision is very time consuming, but probably the most rewarding aspect of being an academic.
I am not danieltillett, but I am familiar with the difference between doing research and supervising research. A tenure-track professor is expected to advise students who do research. The professor's involvement in the day-to-day of the research itself will vary depending on the student's experience, how large the professor's group is, and what the professor wants. While I do know of some professors who did almost an equal amount of day-to-day research work as their student on a project, that is rare, and such professors can typically only have one or two students at at a time.
Instead, a professor is usually spending more time supervising research. This is typically because a professor has multiple students, and as danieltillett explained, they already have many other time commitments. But this is also because the point of the entire process is for the students to become independent researchers. That is, the research supervision is teaching their students how to be researchers. In my experiences, professors in science and engineering tend towards being managers rather than being in the lab or at the keyboard.
I presume danieltillett made this distinction because there is a difference between supervising and doing the research.
I was deliberately terrible at the administration side and outright refused to do anything unless it meant more money for my department (the one good thing about tenure is you can be a pain in the backside and not get fired), but even spending less than 10 hours a week on admin, my work week was rarely less than 80 to 90 hours.
One of the major reasons why I quit academia and went back to my startup was to have more time to spend with my family.