The subject Thermodynamics and Statistical Physics (TFE) is a full course subject, corresponding to 12 ECTS credits. It is compulsory for the Degree in Physics and the double Degree in Physics and Electronic Engineering, while in the Degree in Electronic Engineering it is offered as an optional subject.



Thermodynamics and Statistical Physics is part of the "Basic Concepts" module, which constitutes the fundamental core of physics knowledge that you will need to access any of the possible professions related to physics. The objective of this module is therefore to guarantee that you acquire an adequate understanding of the most fundamental physics, and a solid base so that you can tackle the most advanced subjects of the Degree.



What are you going to see in Thermodynamics and Statistical Physics?



The subject of Thermodynamics and Statistical Physics is divided into two parts: Thermodynamics is developed in the first quarter and Statistical Physics in the second. The two parts are two sides of the same coin, and have the same objective: to predict the equilibrium states of physical systems, making use of their characteristics (through state equations, experimental coefficients, the fundamental equations, etc) and making use of the experimental conditions. The difference is how each of the parts of the course addresses this objective:



• Thermodynamics uses the macroscopic criterion. To predict the equilibrium state of a physical system, it is enough to know the values of a number of macroscopic parameters called thermodynamic quantities, such as pressure, volume, temperature, number of moles, etc. Using theoretical relationships between various magnitudes, such as state equations or fundamental equations) the equilibrium state of the system can be calculated, which defines the rest of the magnitudes.

• Statistical Physics uses the microscopic criterion. To predict the equilibrium state of a system, it is necessary to know the behavior of the fundamental particles that make up the system (usually we talk about atoms). The number of particles is so extraordinarily large that each particle cannot be treated independently and it is necessary to study collective behavior. From this collective or statistical behavior, the macroscopic thermodynamic magnitudes of the system can be calculated.



Within the degree you are studying, Thermodynamics and Statistical Physics is related to one level or another with all the subjects, since it tries to predict properties of any physical system, from a mechanical system such as an engine to an astronomical system such as a white dwarf , going through gases or solids in general. That is why it is a subject in the "Basic Concepts" module.



What do you need to study Thermodynamics and Statistical Physics?



Thermodynamic processes are described by means of differential equations, and therefore a good domain of "Differential and Integral Calculus" of 1º is necessary. The state equations, for example, are the first derivatives of the fundamental equations of the systems, and the experimental coefficients, the second derivatives. In the case of Statistical Physics, mathematical competence is something more special. Apart from what was mentioned above, it is necessary to have notions of probability, distributions and integrals of special functions, how they are calculated and what values they have. Therefore, the subject "Mathematical Methods" of the 2nd year is essential.





What will Thermodynamics and Statistical Physics be used for?



Firstly, there is a direct relationship with the subject of "Experimental Techniques III" of his same course. In Experimental Techniques III you will carry out experiments on thermodynamic magnitudes of various systems, and to understand the physical processes that are taking place, as well as their theoretical justification, you need to take Thermodynamics and Statistical Physics.



From here, the knowledge will be useful to address any advanced course in the 4th year or electives, take Master's degrees, or do PhDs, as well as carry out work outside the academic world. Thermodynamics and Statistical Physics will be especially relevant in fields such as Physics of Materials, various Engineering (Mechanics, Aerospace, Fluids, etc.), Econophysics and Finance, Biophysics, Big Data and Machine Learning, etc.

Statistical Physics. You can see those skills that you will acquire in the following table:



General and Transversal Competences of the Degree

G001 - Learn to pose and correctly solve problems

G003 - Understand physical phenomena theoretically

G005 - Being able to organize, plan and learn independently

G006 - Being able to analyze, synthesize and reason critically

Specific Competences of Module 2

CM01 - Acquire the necessary knowledge to clearly understand the basic principles of Thermodynamics and Statistical Physics and their applications

CM02 - Correctly pose and solve problems involving the main concepts of Thermodynamics and Statistical Physics

CM03 - Document yourself correctly and present work related to Thermodynamics and Statistical Physics in an organized way to consolidate or expand knowledge and to discern between what is important and what is accessory

CM04 - Present in writing and orally problems and questions about Thermodynamics and Statistical Physics, to develop skills in scientific communication



It will be considered that you have acquired these skills as long as at the end of the course you are able to:



Learning outcomes

LO1 - Explain in writing in an orderly and rigorous way the concepts of Thermodynamics and Statistical Physics included in the syllabus (G003, G006, CM01, CM04)

RA2 - Solve basic problems of Thermodynamics and Statistical Physics in a mathematically ordered way (G001, CM02, CM04)

LO3 - Present orally with ease and rigor the theoretical concepts and mathematical developments of Thermodynamics and Statistical Physics included in the agenda (G006, CM04)

LO4 - Reasonably justify physical processes of Thermodynamics and Statistical Physics from the purely numerical results that describe them (G003, G006, CM01)

LO5 - Prepare texts and simple theoretical models on topics of Thermodynamics and Statistical Physics from information collected independently (G005, CM03)

1. Introduction

Concepts and definitions: thermodynamic systems, thermodynamic variables, interactions, processes, equilibrium.



2. Zero Principle (Temperature) Thermal equilibrium.

Zero principle of thermodynamics. temperature concept. Temperature scale, measurement of temperature. (Temperature microscopically).



3. Simple system Simple system.

thermodynamic equilibrium. State equation.



4. First Principle (Internal Energy)

Work: concept of work, mechanical work, compound systems. Heat: system/environment, calorimetric definition of heat, adiabatic work, internal energy. First Law of thermodynamics. Specific heats. heat sources. (I work microscopically).



5. ideal gas

Development of the Virial: equation of state. free expansion. ideal gas. adiabatic processes. Polytropic processes. (Ideal gas microscopically).



6. Second Law (Entropy) Natural asymmetry.

Statements of the second principle. Reversibility/irreversibility. Consequences of the second principle. Clausius's theorem. Principle of increase of entropy. Maximum/minimum work. Usable energy. (entropy microscopically)



7. Special systems

Electric system. magnetic system. elastic system. General system: X, Y. Equations of state, work, calculation of entropy variations



8. Third Principle (Cooling processes)

cooling processes. Statements of the third principle. Physicochemical consequences of the third principle. magnetic system. negative temperatures.



9. Fundamental Equation (Thermodynamic Potentials)

Postulates of thermodynamics. Fundamental equation, equations of state, extremal principles, alternative formulations: thermodynamic potentials, Maxwell relations.



10. Application of the theory (Phase transitions) Stability conditions.

Le'Chatelier principle, Le'Chatelier/Braun principle. First order transitions: van der Waals fluid. Clausius/Clapeyron equation.





STATISTICAL PHYSICS



11. Previous concepts

Introduction. Microstates and macrostates. Connection between Statistical Mechanics and Thermodynamics. Odds. Examples of physical systems: monatomic ideal gas, perfect paramagnetic substance, two-level system. Phase space. Liouville's theorem.



12. Gibbs collectivities. microcanonical set

Introduction. Microcanonical set. Calculations in the microcanonical ensemble. Equipartition and virial theorems. Examples of application of the microcanonical set.



13. Gibbs collectivities. canonical set

Introduction. partition function. Connection with thermodynamics. fluctuations. Examples: classical ideal gas, classical and quantum oscillator systems, perfect paramagnetism. Quantum formulation of the canonical ensemble: density matrix.



14. Gibbs collectivities. macrocanonical set

Introduction. partition function. Connection with thermodynamics. fluctuations. Examples: classical ideal gas, molecules adsorbed on a surface.



15. Quantum Statistics of Ideal Gases

Introduction. partition function. Boson gas: radiation, Bose condensation, superfluids. Fermi gas: metals, white dwarfs.



16. Interacting systems

real gases. Viral development. Approximation of the mean field. Ferromagnetism. Distribution functions in liquids.



17. Phase transitions

Fundamental concepts: order parameter, susceptibility and fluctuations. Ising's model. The Monte Carlo method.



18. Transport phenomena

elementary theory. Boltzmann equation. Approximation of relaxation time.

In the first part Thermodynamics is studied, the first part of the subject and in the second part Statistical Physics is studied, the second part of the subject. Each partial will be evaluated independently, with 2 types of evaluation:



Continuous assessment

The continuous evaluation may consist of intermediate controls and activities to be carried out such as problems or works. The % of each activity will be agreed by the teacher of each partial with the students at the beginning of the partial



Final evaluation

Written test to develop (%): 100

• Continuous Assessment System
• Final Assessment System
• Tools and qualification percentages:
  • Written test to be taken (%): 100

In the ORDINARY call

• Both parts of the course must be passed with a grade ≥ 5.0

• The course can be passed by partials. In case of failing a single partial, the student may only attend that partial in the ORDINARY exam. The mark of the partial approved will be kept.

• The final grade will be the average of both partials

Resignations

• It will be considered that the student waives the continuous evaluation if he does not show up for any control or does not carry out the agreed activities.

• In any case, students will have the right to be evaluated through the final evaluation system, regardless of whether the continuous evaluation system has started, submitting in writing to the teaching staff responsible for the subject the waiver of continuous evaluation with at least 3 weeks notice. prior to the exam session.

• In the event that the student chooses the final evaluation method, the waiver of the ordinary call will be automatic just by not showing up for the test set on the official date.





In the event that sanitary conditions prevent carrying out a face-to-face evaluation, a non-face-to-face evaluation will be activated, of which the students will be informed promptly.

Basic bibliography

D.A. McQuarrie, Statistical Mechanics, Harper and Row, 1976

R.K. Pathria, Statistical Mechanics, Pergamon Press, 1996

F. Reif, Física Estadística y Térmica, Ediciones del Castillo, 1968

F. Reif, Física Estadística, Reverte, 1996

In-depth bibliography

D.A. McQuarrie, Statistical Mechanics, Harper and Row, 1976
F. Reif, Física Estadística y Térmica, Ediciones del Castillo, 1968
F. Reif, Física Estadística, Reverte, 1996