The Second Law of the Thermodynamics

The second law of thermodynamics establishes entropy as a profound property of such a thermodynamic system. Despite following the necessity of conserving energy as specified in the first law of thermodynamics, entropy predicts the route of impulsive events and determines whether they are irreparable or inconceivable. 

The second law may be defined by observing that the entropy of discrete systems allowed to spontaneous development cannot diminish since they ultimately converge at a point of thermodynamic equilibrium with the maximum entropy. Entropy is constant if all processes in the system are reversible. The irrevocability of natural phenomena is explained by a rise in enthalpy, which is typically alluded to in the idea of the flow of time. Previously, the second law was indeed an observational discovery that has been recognised as a thermodynamic theory tenet. Stochastic mechanics explains the principle at a microscopic level regarding the probabilistic distribution of the states of massive assemblages of atoms or molecules. 

This law is concerned with inefficiency, degeneration, and decay. It teaches us that everything we do is essentially useless and that the cosmos contains irreversible processes. It offers us a time arrow and tells us that our cosmos has an unavoidably gloomy and dreary end. Notwithstanding these rather depressing concepts, thermodynamics was developed during enormous technical hope – Industrialisation. In the mid-nineteenth century, physicists and engineers were developing steam engines to automate employment and transportation, attempting to improve their power and efficiency.

Applications of Second Law of Thermodynamics:

The second law is all around us all the time, and it’s the foremost important, most powerful, and most universal principle altogether of science.

Earth’s Age Explanation:

When scientists attempted to calculate the history of the Universe in the 1800s, they came nowhere near to the estimate recognised today. They were also unable to comprehend how the world changed. Lord Kelvin, as previously established, proposed that the Earth’s surface was exceedingly hot, akin to the sun’s surface. He assumed that the world was slowly cooling. Kelvin utilised thermodynamics to calculate that the world was at least twenty million years old because it would take roughly that long for the Earth to cool to its current condition. Twenty million years was not even close to the true age of the Earth, but this was due to scientists not being aware of radioactivity at Kelvin’s time. And although Kelvin was wrong about the planet’s age, his application of the second law enabled him to forecast a relatively precise figure than fellow researchers at the time.

The Evolutionary Principle and the Second Law

Some sceptics argue that evolution contradicts the Second Law of Thermodynamics because it adds organisation and complexity. Unfortunately, this law only applies to isolated systems since the Earth is neither isolated nor closed. This is visible since the sun’s heat causes continual energy increases on Earth. As a result, while the order is getting more organised, the cosmos gets more disorganised as the sun discharges energy and becomes disordered.

Second Law Of Thermodynamics Explained With Examples

It may be hard to wrap your head around this concept so let’s simplify it as much as possible. If you have a glass of hot water and place it into a tub of regular water, what happens? The hot water has more energy/complexity since atoms are more agitated when heat is present. The regular water is at equilibrium with the room temperature. Its temperature is at equilibrium with the room, unlike the hot water in the glass. Considering the hot water glass, its entropy has increased (heat and complexity are lost) since its heat moves to the water in the tub. 

With time, the tub itself loses all the heat that the glass gave to it. So, after a short time, it loses energy by releasing its heat to the surrounding air. For another example of entropy increasing over a period, consider a messy room. With time, all rooms become disordered and disorganised. Even if you clean the room, the entropy within the room can be said to have decreased (because you made it more orderly). But, outside the room, entropy has increased. You may have taken all the trash and left it outside the room, which added to the disorder outside.

Fighting the Second Law of Thermodynamics

You may be beginning to understand this concept already, so let’s look at how we use technology to fight against this law. In a closed (isolated) system, heat will always move from hotter to colder. This is what the law states. But, in an open system (non-isolated), we can transfer heat from a colder region to a warm one. 

For example, in a refrigerator, the heat moves from the colder region (inside the fridge) to a place with a higher temperature (the radiator at the back of the refrigerator). But this can only work by adding electrical energy to the system. This means somewhere outside (wherever the electricity is generated), electrical energy is lost. So as an entire system, entropy is increasing. This law is also known as the Law of Increased Entropy.

Conclusion:

Finally, the second law of thermodynamics is a manifestation of the universal law of rising entropy, which states that the entropy of an isolated system that is not in equilibrium tends to rise as time passes, attaining maximal price equilibrium. The second rule states that temperature disparities between systems in touch tend to be normalised and action may be gained from these disturbance discrepancies; nevertheless, heat loss happens in the form of entropy when work is created. Pressure disparities, particularly temperature differences, tend to equalise if given a chance. This indicates that an isolated system will ultimately reach a stable temperature. As a result, the second rule of thermodynamics states that “it is impossible to build a device that transfers thermal energy into an effort at 100% thermodynamic.” In a nutshell, the term entropy is defined as “the degree of disorder in a system.” In general, the definition of entropy and its relationship to the second rule of thermodynamics is as follows: although free energy is constantly decreasing, entropy is always growing. As a result of the second law of thermodynamics, entropy is one of the essential concepts in science.