I have received replies to my earliest postings which convinced me that my activity is useful. Let me suggest that the second law is not so sacred as it appears - rather, it is an ordinary hypothesis that is easy to verify. Its mythological status comes from the name "Perpetuum mobile of the second kind" - it suggests that those who attempt a verification are just as mad as those who try to produce work out of nothing. Due to this threat, the second law has never been verified for more complex systems (contrary to what textbooks say).

In fact, any system that, under isothermal conditions, can produce two types of work, is suitable for verification of the second law. Consider, for instance, a parallel-plate constant-charge capacitor with vertical plates, suspended over a pull of water. As we slowly draw the plates together, we can extract work - the plates attract each other so, through a pulley, a weight can be lifted. Then we slowly let the capacitor down and immerse it into the pull. There we slowly draw the plates apart until the initial distance between them is restored. The attraction in water is about 80 times smaller, so the work we spend for drawing the plates apart, in water, is 80 times smaller than the work we gain as the plates are drawn together in air. In the final step, the capacitor is taken out of the pull and the initial situation is restored.

If we only consider the net work extracted from the two movements of the plates - first in air and then in water, we obviously have a great gain - much more work gained in air than spent in water. The next question is: at the expense of what is this net work done? There are two possible hypotheses: A) At the expense of work spent by the operator as he immerses and then withdraws the capacitor. B) At the expense of heat absorbed from the surroundings. In the latter case the second law is violated, in the former it is not. Why should thermodynamicists forbidproblems of this kind to be even mentioned? The solution is not easy, but I am sure that, once the problem is openly set, a solution will be attempted by many people, even laymen.
Note that, if the hypothesis B is correct and the second law is violated, the process is still too slow and unsuitable for industrial application. That is the only problem with isothermal heat engines - they are possible but slow and ineffective. Curiously, the first living systems were isothermal heat engines - slowly and ineffectively they "sucked" heat from the surroundings and converted it into energy of chemical structures, until natural selection replaced those mechanisms with much more powerful ones consuming external agents rich in energy, e.g. photons. Ironically, Nature refused to rely on the violation of the second law whereas man believes this violation can resolve the energy crisis.

Best regards,
Pentcho Valev