First law of thermodynamics – It is known as the first law because it is essentially the most important law. In simple terms, thermodynamics states that energy cannot be created or destroyed, but only changed from one state to another. In other words, nothing ever stays still or does not move. Thus, if two systems are both in perfect thermal balance with each other, then they are always in perfect thermal equilibrium with each other and will always be at rest, at a single point called a thermodynamic zero point.
Second law – This is the second most important law of thermodynamics. It says that everything in the universe is constantly in a state of thermal equilibrium. The second law is also called the second law of thermodynamics because no matter can be put in a state of thermal equilibrium, it will eventually come back to its original state, i.e., it will go back to a thermodynamic zero point. The zeroth law is in fact a very simple idea. It is also called the second law of energy because it states that if you remove heat from something, you have to take out the heat from everything that was used in the process as well.
This can be illustrated with a simple example. If you take salt from seawater and boil it, you will, at the end of the process, have saltwater, water, and the original seawater. The second law of thermodynamics states that everything in the universe has a chance of coming to a state of thermal equilibrium, called thermodynamic equilibrium, after which the universe will cease to exist. In other words, everything will become identical, a zero-zero configuration.
Third law – This one states that the total amount of disorder in any system, including the system of thermodynamics, is equal to the difference between its state of order and its state of disorder. The total amount of disorder can be thought of as the total number of ways in which a system can disorder. The zeroth law of thermodynamics therefore states that the total number of ways in which any system can disorder is equal to the number of corners that have the same value for their specific state of order. For instance, there are four particles A, B, C, D and E. These particles are all undergoing thermodynamic processes. Let us call each of these particles a ‘point’.
The second law of thermodynamics is also called the second Law of Thermodynamics. This second law maintains that no matter how many different entities occupy a given area, their collective mean energy will remain zero. The third law of thermodynamics is often referred to as the butterfly effect. The Law of Conservation of Energy, as it is more commonly known, states that energy cannot be lost from a system, only converted or changed from one state to another.
One might think that the last law – of thermodynamics, the second law, thermodynamics in its entirety, would state that a perfect, zero-sum energy exists. However, in reality, the fourth corner of the fourth phase space, that is, the Planck scale, is filled with empty space. Thus, it can not be considered as a pure empty energy field. Although, according to the fourth corner of the Planck scale, there is a great abundance of energy in the universe, the amount of energy experienced by a single unit of matter is finite.
Thus, for thermodynamics to be complete, four laws must be fulfilled. First, there should be a law for the total amount of energy in a system; second, there should be a law for the rate of heat transfer; third, there should be a law for the rate of cooling or dew point; and fourth, there should be a law that explains why different systems exhibit identical physical laws when studied individually. The second, third, and fourth corner are indeed satisfied by the current theory of general relativity (GR), which is the prevalent theoretical framework employed in cosmology and physics today. Although some dispute this fact, no less an authority than Stephen Wolfram has stated that there are no discrepancies so far as GR is concerned. Therefore, although thermodynamics may have many flaws as it currently stands, this particular theoretical framework has so far, succeeded in containing most of the discrepancies that have so far been discovered in the realm of physical science and physics.