Irreversibility against thermodynamics !

In thermodynamic laws considerations about process mechanisms have no significance. The position of equilibriums are calculated by comparison of  states with reference to energy and entropy aspects. Thermodynamics describe not the motion of single atoms/molecules. However, the very large number of atom/molecule processes results the thermodynamic equilibrium. That's why the influence of such elemetary processes will here discussed.
In the picture are two different states with equal or unequal distribution. The thermodynamic logic says, that the equal state has a higher probability than the unequal.  But as simple true it seems , as wrong it is!

 States have not a probabilty! Only  processes have a probability.

In this case it is correct  to say, that the process from unequal to equal distribution has a higher probability than the opposite one.  This is simple but very important.
By addition of the red plank, which can swing only in one direction, the circumstances are very different. The plank causes, that the motion process from left to right as a higher probability than the opposite one. The plank process is an irreversible one, because a single ball can only push it open from left to right. 
The mistake, that states haven't a probability, makes a great difference here. In equilibrium, there is not an equal but an unequal distribution, although the energy and entropy circumstances are the same like in the first picture
Equilibriums, created by irreversible elementary processes, are in thermodynamic calculations non equilibriums. But with a thermodynamic non equilibrium it is possible to produce mechanical motion, symbolized by the wheel. It is a perpetual motion machine of second kind. Other examples of this principle are the Dropping funnel and the Brownian ratchet .

Systems, determined by reversible processes, can be calculated by themodynamic laws. But in systems with irreversible processes, the mistake, that states haven't a probability, make the differece. In such systems the second law of thermodynamics has not validity. Levenspiel's fountain is an example to this principle.

The importance of this principle to living systems is discussed in the link principle of live .

back     next