In my country (India), there are several implicit norms that need to be followed by almost every oneeveryone is expected to follow.
Among all, anOne of the important normnorms is that juniors doesdo not address their seniorsa senior by their name. It happens in both students' circles andas well as in faculty circles -- thus, even junior professors would not address senior professors by name.
Recently (in the US), a female assistant professor addressed a male associate professor by his name. It isThis was the first time ever time that I saw an incident like this personally. I personally consideredeven thought it as an offensewas offensive to the male associate professor.
So, I am wondering whether it is a norm in the US to address seniors as "sir" or any other respectable salutation instead of addressing by name.
Note: The question is broader than only addressing a professor.