# PX265 - Thermal Physics II

• Module code: PX265
• Module name: Thermal Physics II
• Department: Physics
• Credit: 7.5

## Module content and teaching

###### Principal aims

The module introduces statistical mechanics and its central role in physics. It should give you an appreciation of Boltzmann's insights into the nature and role of entropy. You will see many of the ideas introduced here used in the description of the properties of matter in solid state, nuclear and astrophysics modules in the third and fourth years.

###### Principal learning outcomes

At the end of the module you should: Be familiar with the definition of thermal equilibrium, the ergodic hypothesis and the various ensembles; Know the definition and importance of the partition function and be able to calculate thermodynamic averages from it (this includes the Fermi-Dirac and Bose-Einstein distributions); Understand the structure of statistical mechanics and its relation to classical thermodynamics; Be familiar with the notion of degeneracy and the density of states.

###### Timetabled teaching activities

about 18 Lectures + 4 problems classes

https://warwick.ac.uk/fac/sci/physics/current/teach/syllabi/year2/px265

###### Other essential notes

Any macroscopic object we meet contains a large number of particles, each of which moves according to the laws of mechanics (which can be classical or quantum). Yet we can often ignore the details of this microscopic motion and use a few average quantities such as temperature and pressure to describe and predict the behaviour of the object. Why we can do this, when we can do this and how to do it are the subject of this module. The most important idea in the field is due to Boltzmann, who identified the connection between entropy and disorder. The empirical laws of thermodynamics required the existence of entropy, but there was no microscopic definition for it. The module shows how the structure of equilibrium thermodynamics follows from Boltzmann's definition of the entropy and shows how, in principle, any observable equilibrium quantity can be computed. This microscopic theory (now called statistical mechanics) provides the basis for predicting and explaining all thermodynamic properties of matter.

## Module assessment

Assessment group Assessment name Percentage
7.5 CATS (Module code: PX265-7.5)
D (Assessed/examined work) Assessed work as specified by department 15%
Thermal Physics II (Summer) 85%
VA (Visiting students only) 100% assessed (visiting/exchange) PART YEAR 100%

## Module availability

This module is available on the following courses:

###### Core
• Undergraduate Physics (BSc) (F300) - Year 2
• Undergraduate Physics (MPhys) (F303) - Year 2
• Undergraduate Physics (BSc MPhys) (F304) - Year 2