ReTasking Maxwell's Daemon

[studiot]

Like the Daemon, I was getting bored with all the politics threads and this thread was inspired by a question elsewhere where the poster had trouble understanding the difference between the statistics of geometric configurations and the statistics of energy levels as applied to entropy.

So I re-tasked the Daemon as follows.

Consider a rarified gas and let the Daemon take an empty box with a moveable side and capture a single molecule inside the box, so there is nothing else in the box.

The molecule bounces about inside the box as expected.

Question 1)

Is the entropy any difference when the molecule is on the left hand side of the box, the right hand side of the box or in the middle?

Question 2)

Let the Daemon move the movable side in a bit, in the time the molecule is elsewhere and bring the side to a complete halt before the molecule hits it.

Has any work been done?

Question 3)

Would anybody like to make any other comments on the Thermodynamics of the situation?

 

 

Edited October 18, 2017 by studiot

[Roamer]

52 minutes ago, studiot said:

Question 1)

Is the entropy any difference when the molecule is on the left hand side of the box, the right hand side of the box or in the middle?

Only when the wold is different from the east or west will it make difference whether the molecule is more to the east ot west.

54 minutes ago, studiot said:

Question 2)

Let the Daemon move the movable side in a bit, in the time the molecule is elsewhere and bring the side to a complete halt before the molecule hits it.

Has any work been done?

Hmmm, presumably the deamon has put in some effort to get the effect you desire ...

Are you paying him at least minimum wage ??

56 minutes ago, studiot said:

politics threads

I 've never seen science been used correctly in politics,

i actually wanted to make a thread about it, making some scientific standards for politics, but i realized it 'd just fail.

[J.C.MacSwell]

Any fields affecting the space within the empty box that might effect moving the side? Did the Daemon get any outside assistance from pressure on the side he moved? (negative work).

[EdEarl]

2 hours ago, studiot said:

Consider a rarified gas and let the Daemon take an empty box with a moveable side and capture a single molecule inside the box, so there is nothing else in the box.

Space isn't empty, but for sake of this exercise do you mean everyone should assume no virtual particles, no vacuum energy, and no fields.

[studiot]

1 hour ago, J.C.MacSwell said:

Any fields affecting the space within the empty box that might effect moving the side? Did the Daemon get any outside assistance from pressure on the side he moved? (negative work).

I am assuming that long enough time elapses between the capture of the molecule and the moving of the wall for the thermal radiation exchange between the walls and the molecule to equilibrate.
Once equilibrium has been established as there is only one molecule it must travel at constant velocity - there is no group average to consider - and that all wall collisions are elastic.

As far as the Daemon is concerned I am assuming the usual frictionless piston arrangement and reversible movement.

So the volume of the box is reduced.

 

However the Laws of Thermodynamics can't be cheated that easily and work is still done. Yes it will be reversible work under these conditions.

 

Goodnight all until tomorrow.