Lackey, JP Joule would be turning in his grave at how some people are misinterpreting his work and claiming his support for their own theories.
I think everyone is happy with his "free-expansion into a vacuum" experiment. In the demonstration normally presented, the gas is released from its containment on the left, along the x-axis, into the evacuated containment on the right, such that it then occupies both parts of the vessel. The gas comes to rest. The vessel is insulated. The internal mass and energy and heat remain unchanged during the process. No work.
Lets consider the first individual molecule of gas to make that journey. When the gas is released, that molecule is accelerated through the aperture into vacuum. It has velocity. That velocity is the result of the pressure of all its fellow molecules pushing against it. It is an action to the right, and at some point will produce a reaction to the left.
The next molecule does the same thing; same action, same reaction. But now there are 2 molecules in the right hand containment, and they ADDITIONALLY repel each other, so also accelerating along the y- and z-axes. They are expanding freely in a vacuum. But they still have their initial velocity to the right on the x-axis.
Pretty soon, roughly half of the remaining molecules will join their colleagues on the journey. The acceleration of each along the x-axis will be infinitesimally less than the first, because the right-hand containment is beginning to pressurise. Each will accelerate to the right on the x-axis, an action, creating the need for a reaction. They will also expand freely along the y- and z-axes. But you have to remember that whatever acceleration they receive through free-expansion is ADDITIONAL to the velocity they had to the right initially.
Meanwhile, our first molecule has hit the right-hand wall af the containment, and comes to rest. By reducing its velocity to zero, it has accelerated to the LEFT on the x-axis. This is an action to the left, and will produce a reaction to the right. But just a minute, we left an action/reaction pair hanging a few paragraphs back, which is convenient because when we dial that in, then the algebraic equation for all the force applied to Molecule #1 is zero. It started at rest and finished at rest. No action. No reaction. No work. Thank you JPJ.
Now lets transfer the left-hand containment to the infinite majesty of space. When released, our molecules accelerate to the right, an action. Yes, the gas disperses freely in 3 dimensions into the vacuum but the individual molecules retain their velocity along the x-axis. Although the gas is very, very, very dispersed, it hasn't ceased to exist, the molecules still have mass and velocity. They got that velocity by being accelerated out of the containment; an action to the right, producing a reaction of the containment to the left. And because they don't hit the wall of a right hand containment, so there is no second action/reaction pair, they keep going. For ever.
As does the containment, to the left. For ever.
Work done.