So the books author, Professor Peter Atkins, begins telling us in this short story of Thermodynamics. The science sprung up during the 19th century along with the invention with the steam engine. While Thermodynamics does a good job of explaining the mechanical functions of the steam engine, it also explains just about everything in our universe. Included within the study of Thermodynamics are chemical reactions, the relationships between power plants and refrigerators, how lasers function to the fundamental aspects of the human metabolism to include ATP, the biological currency of energy.
There are four laws of Thermodynamics inconveniently beginning with the Zeroth Law, The concept of temperature. The concept of temperature states that when two or more objects come into contact with each other, they will eventually reach a point of thermal equilibrium. Imagine taking a piece of cast iron out of a furnace and dropping into a cold bath of water. The red hotness from disappears while steam escapes from the pool. The steam will stop escaping once the iron and water are at thermal equilibrium.
The first law of Thermodynamics is the conservation of energy. Of all four laws, the first law is the easiest to grasp. It simply states that all of the energy that existed in the beginning of the universe, will exist at the end. Energy cannot be created and it cannot be destroyed. Energy, despite its seemingly endless supply from our vantage point, is still a limited commodity throughout the universe. Energy is defined simply as potential work or schematically written as 1J = Kg*m/s^2 (one joule equals one kilogram-meter per second squared). The trickiest part about this law is defining work, and then differentiating work from energy. For example, lifting a weight is work, but it takes energy to lift the weight. Reading this chapter, I kept thinking about a man squatting. Squatting 100kg takes work, but it expends (costs) energy. Put another way, squatting 100kg up -not down- one meter costs 980J of energy. Doing work costs energy. From reading, that was the best way I could think of the first law.
The increase in entropy is the second law. Often understood as the most difficult law to grasp, the law describes any change that occurs in the universe. It is able to describe why the rocks, particle and dust eventually turned into our Solar System. Entropy describes how you awoke in the morning, even why the wind blows or how a man squats. Any and all changes can always be directed back to the second law of thermodynamics, entropy. Entropy is a bit of a tough nugget to crack. The basic premise is that the natural order, or “spontaneously” in the language of science and thermodynamics, of things is to move from an ordered state to a disordered state. It is natural for entropy to spontaneously increase over time. Going against spontaneously increasing entropy takes work. Doing my best to explain entropy with the squatter above. It is natural for a 100kg barbell to move spontaneously -not quickly, but naturally- to be pulled towards the ground by the force of gravity. The human body may be likened to an efficient machine, but not perfectly so. Much of the energy that the muscles and the central nervous system are using are being used for work to push the bar against gravity, but not all. A small or fair amount of that energy is being lost to heat; the transference of energy and heat sink must be created to cover for the lost energy. Hence, you sweat when you work hard. There is, of course, much more to be discussed with phenomenon of entropy, but they are outside the scope of this blog.
The third and final law is often thought of a trivial law. The third law simply refers to the unattainability of zero. That is to say that reaching a temperature of zero kelvins (T=0) is impossible in a world of finite possibilities. Going below zero kelvins is certainly possible and is observed in lasers on a DVD player, for example. Beyond that, there really isn’t much to say about the third law.
Summarizing the science of thermodynamics as the study of the transference of energy seems to be a lot more than that. Studying temperature, heat and energy describes everything that is found in nature and may even give us some insight on how to produce better athletes. The transference of energy from food to performance is entirely in the realm of Thermodynamics.