The Thermodynamic Laws of the Universe on Heat, Energy, Work

 

Thermodynamics is a common interest in physics and engineering. While physics studies the most fundamental questions of thermodynamics, the engineering field provides the development of mechanical systems suitable for the answers to these questions. If we look at the definition of thermodynamics;

Thermodynamics examines the concepts such as heat, temperature, energy, work in macroscopic structures (in certain cases also in microscopic structures) and their relationship with each other, and the movement of heat under various forces.

There are four laws of thermodynamics:

Zeroth Law of Thermodynamics

The zeroth law, which emerged after the three laws that came after it, reveals the most basic equilibrium rule of the universe and answers the question of what is temperature. According to this law, when we measure object A and object B with a thermometer, if they are in thermal equilibrium, that is, if there is no heat exchange between them, if there is no heat exchange in substance C when we contact substance C, whose temperature we do not know, with object A or object B, we can easily say that the temperature is equal between these three.

If we formulate it; 

 A = B ∧ B = C ⟹ A = C

First Law of Thermodynamics

The first law of thermodynamics tells us that the energy in the universe will never be lost, even if it changes for various reasons. If we think of the universe as a closed system, the energy existing in the universe cannot be destroyed, and nonexistent energy cannot be created. Energies can be converted into each other, provided that they are conserved. 

Second Law of Thermodynamics

The second law tells us the direction of energy flow. According to this law, there is no flow from low energy to high energy, so to give an example, heat from hot water with high energy flows towards cold water with lower energy. The direction of the energy flow creates the concept of entropy. In the following sections, we will have an article where we will explain the details of the concept of entropy and its relationship with time, but if we talk about it briefly, entropy is going from less order to more complex. Entropy always tends to increase. If the entropy of a system is zero, it means that there is no disorder in that system, and it says that work done in the process is reversible, that is, it can return to its original state. If the entropy is in the positive direction, it says that the disorder is increasing and the work done in the system cannot be reversed.

Third Law of Thermodynamics

The third law says that if you constantly lower the temperature of a system, you can lower it to the maximum absolute zero, 0 Kelvin, or -273.15 degrees Celsius. This law, which tells us that entropy can decrease in the second law, actually states that absolute zero is the lowest limit that can be reduced in nature. Below this limit, there is no temperature. In order to achieve this, infinite energy and infinite time are needed.

Reference

https://en.wikipedia.org/wiki/Thermodynamics