Open Door Systems

While in the past, we have been mainly studying room cleanliness behind closed doors, rooms are not necessarily closed. For instance, while food cannot magically appear inside a room and then disappear, food can be brought into a room, eaten there, then removed in the form of garbage. While the net amount of items brought into the room in the long run is approximately none, in the short run, the rise and fall of the number of objects can make a difference in the overall cleanliness. For example, influxes of food items may leave trash in the room for days or weeks after having been eaten. This short term increase means, in the short run, the room is made more dirty. On the other hand, removing said trash from the room will have a positive effect.