Free God and the Folly of Faith: The Incompatibility of Science and Religion by Victor J. Stenger Page B

it is useful. The first law of thermodynamics extended the principle of energy conservation to processes involving heat. It said that the change in the internal energy of a system must equal the work done by the system minus the heat produced, or, equivalently, plus the heat added to the system. These quantities can be positive or negative. For example, with a refrigerator or air conditioner, the work done by a system and the heat added to a system are negative; that is, work comes in and heat goes out.
    It was observed that it seemed impossible to build a perfect heat engine, one that converted all the input heat into work. It also seemed impossible to build a perfect refrigerator that just lowered the temperature of a system without doing any work on the system. The latter also implied that heat always flows from a hotter body to a colder one in the absence of work. Although allowed by the first law of thermodynamics, since energy is still conserved, some heat processes such as this were irreversible. This suggested a second law of thermodynamics. There are several versions that are all equivalent: you cannot build a perfect heat engine; you cannot build a perfect refrigerator; heat always flows from high to low temperature.
    For example, suppose two blocks of lead are inside a rigid, insulated box that does not allow any heat or work in or out. One block is at a higher temperature than the other. When you bring them in contact, heat will flow from the higher to the lower temperature body. Eventually the two will reach an equilibrium temperature in between the two initial temperatures.
    Although allowed by energy conservation, you will never see the cooler body transferring heat to the hotter one, lowering its temperature further and raising the temperature of the hotter body even more without doing work. That would be a perfect refrigerator and we could use it to build a perfect heat engine. A perfect heat engine would be a perpetual motion machine. The second law of thermodynamics forbids these.
    The second law was shown to be equivalent to the statement that a certainmathematical quantity called entropy must remain constant or increase in time in a closed system. That is, the entropy of a closed system can never decrease. This accounts for the fact that some processes are apparently irreversible. The reverse process would violate the second law. Entropy was seen to be a measure of the disorder of a system, which when left alone eventually decays and runs down. For example, when a living organism dies, it is no longer able to input energy and eventually dissolves back into dust.
    Being a closed system, the second law implies that the universe will eventually run down in what is called “heat death.” However, that will not happen for many trillions of years.
    THERMOTHEOLOGY
     
    As Danish historian Helge S. Kragh describes in her unique study, Entropic Creation: Religious Contexts of Thermodynamics and Cosmology , published in 2008, ancient thinkers debated whether the universe was eternal or had a finite lifetime. 2 Aristotle thought it was eternal while Stoic philosophers argued that the evidence for irreversible decay is all around us. Around 320 BCE, the philosopher Zeno of Citrium remarked that if Earth had always existed, erosion would have flattened out all the mountains. 3 Of course, we now know that Earth did not always exist; rather, it formed 4.5 billion years ago and, furthermore, mountains are continually regenerated by the collisions of tectonic plates.
    Early Christian thinkers such as John Philoponus (died 570) systematically argued against the eternity of the world (read “universe”) since it challenged the doctrine of the creation. During the scientific revolution it was widely believed that the universe was slowly deteriorating. This was consistent with theological notions. For example, Martin Luther said, “The world degenerates and grows worse and worse every day…[and] will perish shortly.”