In the early days of quantum mechanics, it was thought that the theory would do away with classical thermodynamics. This was because quantum mechanics seemed to imply that particles could exist in more than one state at a time, which classical thermodynamics could not explain. However, it was soon realized that quantum mechanics could actually be used to explain classical thermodynamics. In fact, quantum mechanics makes classical thermodynamics even more accurate.

One of the key ways in which quantum mechanics changed classical thermodynamics is by providing a more accurate description of the behavior of particles. In classical thermodynamics, it was assumed that particles could only exist in one state at a time. However, quantum mechanics shows that particles can actually exist in multiple states at the same time. This means that classical thermodynamics is actually an approximation of the true behavior of particles.

Another way in which quantum mechanics changed classical thermodynamics is by providing a more accurate description of the behavior of heat. In classical thermodynamics, it was assumed that heat always flowed from hot objects to cold objects. However, quantum mechanics shows that this is not always the case. In fact, quantum mechanics predicts that heat can flow from cold objects to hot objects. This means that classical thermodynamics is actually an approximation of the true behavior of heat.

Overall, quantum mechanics has changed classical thermodynamics in a number of ways. The most important change is that quantum mechanics has provided a more accurate description of the behavior of particles and heat. This has led to a more accurate understanding of the behavior of matter and energy.

## Other related questions:

### Q: How does thermodynamics relate to quantum mechanics?

A: In quantum mechanics, thermodynamics is the study of the behavior of systems whose behavior is governed by the laws of quantum mechanics.

### Q: What is the relation between quantum mechanics and classical mechanics?

A: Quantum mechanics is a branch of physics that studies the behavior of matter and energy at the atomic and subatomic levels. Classical mechanics is a branch of physics that studies the behavior of matter and energy at the macroscopic level.

### Q: Does quantum mechanics follow thermodynamics?

A: There is no definitive answer to this question as the two fields are quite distinct from one another. However, there are some interesting connections between the two fields that have been explored by scientists over the years.

### Q: Can quantum mechanics explain classical mechanics?

A: Quantum mechanics can explain classical mechanics in several ways. For example, by understanding the behavior of subatomic particles, quantum mechanics can help explain the behavior of larger objects. Additionally, by understanding the wave-particle duality of matter, quantum mechanics can help explain why some objects behave like waves and others like particles. Additionally, quantum mechanics can help explain the behavior of objects in extreme conditions, such as at very high temperatures or very small scales.

## Bibliography

- How Did Quantum Mechanics Change Classical …
- The Quantum Thermodynamics Revolution | Quanta Magazine
- Quantum thermodynamics – Wikipedia
- Journey from Classical to Quantum in Two Dimensions
- Entropy and quantum mechanics – Richard Fitzpatrick
- Thermodynamics and the structure of quantum theory
- Statistical physics