 In this module we will be introducing the language of thermodynamics. Now thermodynamics is a pretty wide subject with many different possible applications. So for the purpose of this class we're just going to introduce a number of critical concepts on which a lot of our conversations will be founded. And those critical concepts are the idea of energy, equilibrium and the idea of a system. Behind me is Kinsodam and you can see in here that energy does not have to be a very abstract concept. Here you can see the water that is going to turn the turbines and produce electricity. In other words we're seeing energy in action. It's a very large banner in which it gets a whole geologic superior name after the state. And the reason for this is because of the abundance and the widespread presence of cold beds that form during this same period of time. As you take inland organic petrities and you isolate it from the atmosphere and from the hydrosphere. At that point you're going to cook it at a variety of temperatures and pressures. Depending on the temperature and depending on the pressure under which these materials form you're going to get different grades of cold. Now this would be pretty ideal if you were to be forming only the cold. The complication is that just about every mineral forms as part of a rock. When you have a rock what you have is other minerals. Other minerals that we do not want if you're trying to extract more energy. So what this means is two things. It means that you have to separate those minerals from the coal. And it also means that you're going to be producing a large amount of talents as a consequence of it. The interesting part is that you can stop production of the coal. But those minerals that were present there are still going to be exposed to the conditions in the surface of the planet. And that can create... Outside of the city of Altoona in central Pennsylvania. And you might notice something unusual about these streams. Namely it is orange. This is colloquially known as yellow boy. And it forms by the deposition of iron oxides. How do these iron oxides form? Well this has to do with one of the major drivers of the local economy. And that has been the extraction of coal. As coal is extracted we're moving from a closed system in the crust of the Earth to an open system that is exposed to the atmosphere and exposed to groundwater and to surface waters. So the consequences that that has is that the minerals that came along with the coal are going to react with the water and are going to react with the atmosphere. That will result in the breakdown or oxidation of many of the minerals that were present there. So one of the major culprits for the color of this material is the presence of an iron sulfide called pyrite. Pyrite contains basically two atoms, iron and sulfur. But when it oxidizes it produces iron oxides and it releases sulfur into the water. That results into acidification of the stream and death of the fish that were originally living in it. So you see that moving from one type of system to the other has consequences. And also moving from a system that is in equilibrium under one set of conditions to another system in which you are completely out of equilibrium will result in pretty drastic consequences. So here we have two concepts of this chapter and thermodynamics being represented. The concept of open and closed systems and the concept of equilibrium and disequilibrium.