"Please do not open this door."

This is one of the oddest signs I’ve every seen: “Please do not open this door. Doing so affects the system mechanics.” I can imagine it at the beginning of an indie sci-fi film. It raises all sorts of interesting questions. Why don’t they just lock the door? What system would be affected? How would it be affected? And then there are the design questions. Why design a door that should not be opened? Why design a system whose mechanics would be adversely affected by the casual actions of any random passerby? How complex can the system mechanics associated with a door be? What small but significant percentage of the human population would be motivated by such a sign to go ahead and open the door – whether they wanted to gain entry or not – just to see what happens? One’s mind boggles at the unspoken possibilities.