A thread in the math forum made me feel the need to address this as it is a real problem not just in this forum, but in life in general. The thread was junior high kid asking about how to find the slope of a line. The explanations went WAAAY over his head. They were far more complicated than they needed to be. I'm a mechanical engineer designing HVAC systems. I was recently talking to the principal of a school we're working for and 2 minutes into a discussion of their systems she asked: what's a CFM. Oops. Some things are so basic once you know them that you forget if someone hasn't seen it before its not so basic to them. There is a physics q&a site where I saw a question about the venturi effect and went something like this: If air flowing past a car window pulls a vacuum, why don't the people in the car suffocate? The response (not kidding) was written by a phd candidate and was a good 400 words going into excruciating detail on about the level of a 1st or 2nd year aerospace engineering student. I am SURE whoever wrote the question didn't get 3 sentences into the response. All that was needed was a sentence on guage vs absolute pressure and a sentence explaining how the venturi effect is only a LITTLE vacuum. I'm not sure there is much of a discussion in this, but I just felt the need to editorialize. Opinions?