I see many STEM professors work well into their 70s, 80s, and sometimes even into their early 90s - mostly in teaching, but their research careers were outstanding. One of them that I spoke with told me that he hasn't done research in many years - though he teaches a class every semester.
Do STEM professors "retire" from research at age 65, while continuing to teach and enjoy their tenure? Or are many professors still active in research past retirement age?
I'm asking primarily about US universities.