Course Name: Paradigms in Physics: Energy and Entropy

Course Number: PH 423

Year/Term: 2026
Display other available years here.

Course Credits: 3

Class meeting times: 7 hours of lecture per week for five weeks

Prerequisites: Recommended PH 213

Course description: Thermodynamics and canonical statistical mechanics.

Topic/Day

Activities

Resources

Homework Due

Day 1 W1 D1

Syllabus
Thermodynamic properties
State variables

Working in small groups
A glass of water

Schroeder Preface (perspective on thermodynamics and statistical mechanics)
Schroeder Sections 1.1 to 1.5 (prerequisite background)

Day 2 W1 D2

Interpreting derivatives

Name the experiment

Day 3 W1 D3

Ice calorimetry lab

Ice Calorimetry Lab

Textbook reading: Schroeder section 1.6 "Heat Capacities".

HW 1 w/Solution

Day 4 W2 D1

Math Bits:
Differentials

Zapping with d (Lecture)

Differentials (4:08)
GMM: Differentials
GMM: Rules for Differentials
GMM: Properties of Differentials
GMM: Differentials: Summary

Math Bits:
The Multivariable Chain Rule

Product Rule for Differentials (3:14)
Chain Rule for Differentials (2:25) GMM: The Multivariable Differential
GMM: Chain Rule
GMM: Applications of Chain Rule
GMM: Interpreting Differentials

Math Bits:
Derivatives and differentials

Day 5 W2 D2

Math Bits:

The Isothermal Bulk Modulus (Ethan version)
Zapping With d 1

Prep 5 w/Solution

Math Bits:
Chain Rule Diagrams

Chain Rules (Lecture)

GMM: Chain Rule via Tree Diagrams
GMM: Things NOT to do with differentials

Day 6 W2 D3

New Row

Lab 1
Lab 1: Ice Calorimetry w/Solution

New Row

Day 7 W3 D1

Derivative of 1D function, 2D function

Isolength and Isoforce Stretchability on the PDM
Derivatives Are Observable (Lecture)
Thermodynamic Systems (Lecture)

GMM: Thick Derivatives
GMM: Leibniz Notation
State variables (4:05)
Thermodynamic systems (4:31)

Math Bits:
PDM Dictionary

Name the experiment (PDM Dictionary)

Day 8 W3 D2

Math Bits:
Partial Derivatives (activity with surface)

HW 2 w/Solution

Math Bits:
Other multivariable systems

Isolength and Isoforce Stretchability on the PDM

Day 9 W4 D1

Math Bits:
Cycles

Cat Elevator

Day 10 W4 D2

Math Bits:
State variables on the PDM

Physical Properties of the PDM
Introducing differentials and thermodynamic identity
Name the experiment

Class video (60:00)
Intensive vs. extensive definition (3:49)
Algebra with intensive and extensive quantities (4:53)

Day 11 W4 D3

Second Law

Second Law and Entropy
Thermodynamic Identity
Free expansion

Second Law of Thermodynamics (1:17)
Thermodynamic identity (7:12)

Day 12 W5 D1

First and Second Laws of thermodynamics

Energy, heat and entropy
Fast and Slow
The First Law of Thermodynamics
Thermodynamic Identity
Free expansion

Heat and entropy (4:44)
What is entropy? (3:14)

Practice midterm (not graded)

Midterm review

Midterm Review PH423 Ethan

Day 13 W5 D2

Symmetry of partial derivatives

Maxwell relations

Day 14 W5 D3

Discussion of free expansion worksheet

Free expansion

HW 3 w/Solution

Day 15 W6 D1

Melting ice activity

Heat Capacity and Entropy
Melting Ice Lab

Heat capacity and entropy (9:33)

Day 16 W6 D2

Engines and Fridges

Heat Engines
Other views of the Second Law

Day 17 W6 D3

Changing entropy
Heat and Work

Using $pV$ and $TS$ Plots

Lab 3: Melting Ice

Day 18 W7 D1

Thermodynamics practice

Analyzing a Simple Cycle Using a $p V$ Diagram

Efficiency of reversible heat engines (4:48)
Reversible heat engines and cycles (5:57)

Prep 18 w/Solution

Day 19 W7 D2

Debrief on midterm results

Name the experiment (changing entropy)
Finding entropy review

Day 20 W7 D3

Thermodynamic potentials
Maxwell Relations

Thermodynamic Potentials
Maxwell relations

Work or no work? (2min42s)

HW 4

Thermodynamics Practice

Section 2.1 Schroder
Name the experiment (Maxwell relations)

Video of Feynman discussing the rubber band

Day 21 W8 D1

New Row

Day 22 W8 D2

New Row

Math Bits
Legendre transformations

Legendre Transformations on the PDM

Day 23 W8 D3

New Row

HW 5

Day 24 W9 D1

The Rubber Band Lab

You will be collecting data to quantify the decrease in entropy when a rubber band is isothermally stretched.

Day 25 W9 D2

Segway to Stat Mech

Intro to Statistical Approach
Hakonen 1994 Science Article

Day 26 W9 D3

The Boltzmann factor

Interstellar medium

Lab 4: Rubber Band

Day 27 W10 D1

Topic for Monday

Interstellar medium

Day 28 W10 D2

Boltzmann Statistics

Day 29 W10 D3

Boltzmann Statistics

Water Bending

HW 6

Day 27 Thurs 10/31

Thermodynamic properties from Boltzmann Stats

Concept review

Thermodynamics Game Show

Day 28 Fri 11/1

Review

Boltzmann Factor Practice Question
Energy and Entropy review
Energy and Entropy equation sheet

Final - Mon 16 March

Final exam

7:00pm - 9:00pm on Monday evening.

Additional material

Math Bits:
Internal energy on PDM

Internal Energy on the PDM (Lecture)

Black Body Radiation

Thermodynamics of black body radiation
Review of Thermodynamics
Quasistatic Revisited
Black Body Objects

Additional material

Statistical mechanics of air

Quantum Spectra
Diatomic ideal gas
Internal Energy of a Diatomic Ideal Gas

Quantum spectra (5:44)
Ideal gas with N molecules (20:50)

Additional material

Statistical mechanics of air

Recap of activity
Limiting Cases

Additional material

MIDTERM

HW8 (updated 5:23pm 10/28)
Not used

Finish Statistical mechanics of air

Before classes start