"It is crystal-clear (to me) that all confusions related to the far-reaching fundamental Laws of Thermodynamics, and especially the Second Law, are due to the lack of their genuine and subtle comprehension."

The Second Law made its appearance around 1850, and almost a century later, the physicist/philosopher Bridgman (1941) still complained that “there are almost as many formulations of the Second Law as there have been discussions of it.” Even today, the Sec­ond Law remains so obscure, due to the lack of its comprehension, that it continues to attract new efforts at clarification, including this one. Einstein, whose early writings were related to the Second Law, remained convinced throughout his life that “thermodynamics is the only universal physical theory that will never be refuted.” Namely, the phenomenological Laws of Thermodynamics have much wider, including philosophical significance and implication, than their simple expressions based on the experimental observations.

It is only possible to produce work during energy exchange between systems in non-equilibrium, therefore, the work potential is measure of the systems’ non-equilibrium, thus the work potential could be conserved only in processes if the non-equilibrium is preserved (conserved, i.e. rearranged), and such ideal processes could be reversed (reversible processes). Therefore, it is impossible to produce work from a single thermal reservoir in equilibrium, then a non-equilibrium will be spontaneously created.

Non-equilibrium, i.e., non-uniform distribution of mass-energy in space tends, in time, to spontaneously and irreversibly redistribute over space towards common equilibrium, thus non-equilibrium cannot be spontaneously created. All natural spontaneous, or over-all processes (proceeding by itself and without interaction with the rest of the surroundings) between systems in non-equilibrium have tendency towards common equilibrium and thus irreversible loss of the original work potential (measure of non-equilibrium), by converting other energy forms into the thermal energy accompanied with increase of entropy (randomized equi-partition of energy per absolute temperature level).

The spontaneous forced tendency of mass-energy transfer is due to a difference or non-equilibrium in space of the mass-energy space-density or mass-energy-potential. As mass-energy is transferred from higher to lower potential, and thus conserved, the lower mass-energy potential is increased on the expense of the higher potential until the two equalize, i.e., until a lasting equilibrium is established. THAT explains a process tendency towards the common equilibrium and impossibility of otherwise. If a non-equilibrium is preserved in part or in whole then the preserved mass-energy transfer is termed as a "work", the "in whole" being the maximum possible or the work potential. In a process the (maximum) work potential will in part or in whole be irreversibly converted (i.e., dissipated via "heat" transfer) into newly generated thermal energy ("randomized" energy) thus generating/increasing the entropy (generated thermal energy per absolute temperature). If, in limit, the dissipated work potential is infinitesimal, then the original non-equilibrium is preserved, i.e., rearranged only, and thus the process could be reversed, in limit again, to the original non-equilibrium -  a reversible process. THEREFORE, it is impossible to produce work from a single thermal reservoir in equilibrium, then a non-equilibrium (stored work potential) will be spontaneously created. FURTHERMORE, the spontaneous creation of non-equilibrium will in time "siphon" or compress all existing mass-energy, in limit, into an infinitesimal space with infinite mass-energy potential singularity, thus contradicting the equilibrium space existence in time. ["Spontaneous" imply "by itself" or "on its own" and without inertial and/or reversible/elastic forcing which may produce local non-equilibrium of one kind on the expense of others - again, the non-equilibrium cannot be created spontaneously, but only "lost", i.e., transferred to equilibrium !]

The Second Law has been challenged by some, since certain technical, physical, chemical, biological, and/or intelligent processes produce local non-equilibrium, like moving fluid or refrigeration-heat to higher elevation/temperature, cyclone or crystal formation, in life-creating processes or cognitive reasoning  (by increasing local non-equilibrium, i.e., energy density/potential/organization); however the over-all non-equilibrium, including all interacting boundary systems, i.e. affected environment (very important) only proceed towards over-all (global) equilibrium with over-all entropy increase. In many processes the latter could be confirmed experimentally but some appear to be mysterious and self-organizing; however, the miracles are until they are comprehended and understood.
(see also Definition of Energy, Entropy and The 2nd Law)

Short Bio:

Professor Kostic's teaching and research interests are in Thermodynamics (a science of energy, the Mother of All Sciences), Fluid Mechanics, Heat Transfer and related fluid-thermal-energy sciences; with emphases on physical comprehension and creative design, experimental methods with computerized data acquisition, and CFD simulation; including nanotechnology and development of new-hybrid, POLY-nanofluids with enhanced properties, as well as design, analysis and optimization of fluids-thermal-energy components and systems in power-conversion, utilizations, manufacturing and material processing. Dr. Kostic came to Northern Illinois University from the University of Illinois at Chicago, where he supervised and conducted a two-year research program in heat transfer and viscoelastic fluid flows, after working for some time in industry.

            Dr. Kostic has received recognized professional fellowships and awards, including multiple citations in Marquis' "Who's Who in the World," "Who's Who in America," "Who's Who in American Education," and "Who's Who in Science and Engineering"; the Fulbright Grant; NASA Faculty Fellowship; Sabbatical Semester at Fermilab as a Guest Scientist; and the summer Faculty Research Participation Program at Argonne National Laboratory. He is a frequent reviewer of professional works and books in Thermodynamics and Experimental Methods. Dr. Kostic is a licensed professional engineer (PE or P.Eng.) in Illinois and a member of the ASME, ASEE, and AIP's Society of Rheology. He has a number of publications in refereed journals, including invited state-of-the-art chapters in the Academic Press series Advances in Heat Transfer, Volume 19, and "Viscosity" in  CRC Press' Measurement, Instrumentation and Sensors Handbook; as well as invited reference articles: Work, Power, and Energy in Academic Press/Elsevier's Encyclopedia of Energy; Extrusion Die Design in Dekker's  Encyclopedia of Chemical Processing; and Energy: Global and Historical Background, and Physics of Energy, both in Taylor & Francis/CRC Press Encyclopedia of Energy Engineering and Technology. Professor Kostic is a senior member of the Graduate Faculty at Northern Illinois University
(More at www.kostic.niu.edu or Google <kostic>).