That reminds me of an old joke that sorta strikes home here.If one were to put a little "smoke" in the air,
Three optical engineers were in the lab one day where a technician had just completed a prototype.
The engineers were arguing about the light path and location of focal points in the apparatus, each had a different idea of what was going on.
The technician, after listening to this for a while, decided he was fed up with the discussion. He light up a cigarette, blew some smoke into the light path, and walked away.