# Laws of thermodynamics basically establish its properties?

• swampwiz
In summary, the laws of thermodynamics were developed to establish the thermodynamic properties of temperature, internal energy, and entropy, and they evolved together with our understanding of these concepts.

#### swampwiz

Do the laws of thermodynamics basically establish its properties?

I got to thinking, and it seems that the main purpose of the laws of thermodynamics is to establish that the thermodynamic properties.

0th & 3rd - establish Termperature as a valid property via ability to have equality & scale, respectively

1st - establishes Internal Energy as a property (i.e., what change results from the net influx of thermodynamic energy)

2nd - establishes Entropy as a property, while also formally affixing a true Temperature (i.e., as per the rule that the infimum of the net change in Entropy, which is defined in part by Temperature, is 0)

swampwiz said:
Do the laws of thermodynamics basically establish its properties?

I got to thinking, and it seems that the main purpose of the laws of thermodynamics is to establish that the thermodynamic properties.

0th & 3rd - establish Termperature as a valid property via ability to have equality & scale, respectively

1st - establishes Internal Energy as a property (i.e., what change results from the net influx of thermodynamic energy)

2nd - establishes Entropy as a property, while also formally affixing a true Temperature (i.e., as per the rule that the infimum of the net change in Entropy, which is defined in part by Temperature, is 0)
The answer to "what came first, the laws of thermodynamics or establishing/defining thermodynamic properties" is the same as the answer to "what came first, the chicken or the egg?". The answer is (probably) "neither, they both evolved together". Thermodynamics developed from various attempts to provide a theoretical foundation to explain how heat is used to do useful mechanical work.

The first law, and the concept of internal energy, followed from the recognition that heat flow was really a flow of energy - a concept that was poorly understood until well into the 19th century.

The second law started out as a simple statement that spontaneous heat flow occurs only from hotter to cooler bodies. The concept of temperature is essential to this. With the development of the kinetic theory of gases, the statistical concepts behind temperature and entropy became clearer.

## 1. What are the four laws of thermodynamics?

The four laws of thermodynamics are:
1. Zeroth Law: If two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.
2. First Law: Energy can neither be created nor destroyed, it can only be transferred or converted from one form to another.
3. Second Law: The total entropy of a closed system always increases over time, or remains constant in ideal cases where the system is in a steady state or undergoing a reversible process.
4. Third Law: As the temperature of a system approaches absolute zero, its entropy also approaches a constant minimum value.

## 2. How do the laws of thermodynamics relate to energy?

The laws of thermodynamics govern the behavior of energy in a system. They explain how energy can be transferred or converted from one form to another, and how it affects the overall state of a system.

## 3. Why are the laws of thermodynamics important?

The laws of thermodynamics are important because they provide a fundamental understanding of how energy works in our universe. They are essential in fields such as physics, chemistry, and engineering, and have practical applications in various industries such as energy production, refrigeration, and transportation.

## 4. Are there any exceptions to the laws of thermodynamics?

While the laws of thermodynamics are considered fundamental principles, there are some exceptions and limitations. For example, the Third Law only applies to systems at absolute zero temperature, which is impossible to achieve. There are also cases where the Second Law may not hold true, such as in quantum systems or in the early universe.

## 5. How do the laws of thermodynamics impact our daily lives?

The laws of thermodynamics play a crucial role in our daily lives. They explain how our bodies convert food into energy, how our appliances work, and how our environment and climate are affected by energy transfer and conversion. They are also essential in industries such as transportation, manufacturing, and energy production, which impact our daily lives in countless ways.