Maxwell's Demon bug, trapdoor space and time What about the size of the door (space) and how long has it to be opened (time)?
I think Maxwell's demon would have a problem with space, if the door is too wide (more than one particle size), then direct interaction between the two part is possible and would lead to lose isolation restriction, like there were no demon, (even no isolation wall). On the other hand, if the door is too narrow, then no particle can go into or it will let pass only those which are direct aimed, then Maxwell's demon would lose its freedom of choice because the narrow gate itself "choose" particles having a direction perpendicular to the wall, despite any module criterion (no temperature can be chosen) again it is like there were no demon.
Finally assuming that there were an exact size door being useful for the demon work, then time would be the problem, when the door is open too long, both side particles can cross or collide, like there were no demon!, and if the door is opened too little time, then it only could "select" fast particles from both sides,then it couldn't separate temperatures.
I've read very complex arguments against Maxwell's Demon, concerning information store but I think size and time constraint could be enough arguments to defeat Maxwell's Demon, Do you know any related work about size and time constraint ?
Thanks
 A: Some of your concerns are valid, although irrelevant for the argument's sake. For instance, regarding the size of the door, the demon can have many doors across the wall and open only the one he needs, at the time it needs to. The likelihood of two particles coming from both sides at exactly the same time is almost nil, so if the daemon is fast enough he can always select the particle that he wants to cross to the other side.
A: Let us imagine a baseball player that is also a Maxwell's demon, and perfectly elastic baseball balls, that are flying around randomly. When the demon sees a fast ball, he catches it with a baseball glove. Now the demon has already done what a demon is supposed to do: catch one or more fast molecules. 
If the demon must collect many balls into a container, there is very little problem collecting a few balls into a large container. As the container fills up the demon must be smarter and quicker.  
Oh yes, the demon could also just drop the ball. The glove heats up anyway. I mean the energy is collected in the molecules of the glove.
A demon whose temperature is 0 Kelvins does not need any energy at all. The warmer the demon the more energy its brain uses to compute. This is actually very simple! 
here is a story about some kind of maxwells demon device
here is a game where one can be a maxwells demon
