So I’m trying to work out the concepts of time-reversibility and time-reversal invariance in a descriptive visual sense.
Working from the idea of the two plates proposed in the text book.
For a time-reversal invariant process you can use the example of rubber between the plates. If you gave the top plate a push to the right the rubber would spring back to the left. And the same motion occurs in reverse. With the rubber ‘supplying’ the initial push to the right.
However if you have a viscous fluid in between the sheets you have time-reversibility. If you push the top plate to the right, it moves to the right and stops as the movement is dissipated by friction. In reverse you can’t use the heat that is formed from the friction to propel the plate back to the left; instead you must supply the force yourself.
Is this accurate? What happens when you have a ‘turbulent flow’ liquid between the plates what happens then? Would it also be time-reversal, with a longer deceleration time due to inertia?