Paradigms in Physics: Energy and Entropy | 2026-Winter

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
HW 1
Day 2 W1 D3
Ice calorimetry lab
Ice Calorimetry Lab
Textbook reading: Schroeder section 1.6 "Heat Capacities".
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)
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
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)
HW0
Math Bits:
PDM Dictionary
Name the experiment (PDM Dictionary)
Day 7 W3 D1
Math Bits:
Other multivariable systems
Isolength and Isoforce Stretchability on the PDM
Day 8 W3 D2
Math Bits:
Partial Derivatives (activity with surface)
HW 2
Day 9 Mon 10/7
Symmetry of partial derivatives
Maxwell relations
Day 10 Tues 10/8
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)
HW 3
Melting ice activity
Heat Capacity and Entropy
Melting Ice Lab
Heat capacity and entropy (9:33)
Day 11 Wed 10/9
Second Law
Second Law and Entropy
Thermodynamic Identity
Free expansion
Second Law of Thermodynamics (1:17)
Thermodynamic identity (7:12)
Day 12 Thurs 10/10
Discussion of free expansion worksheet
Free expansion
Day 13 Fri 10/11
Midterm review
HW 4
Day 14 Mon 10/14
Midterm review
Midterm Review PH423 Ethan
Practice midterm (not graded)
Day 15 Tues 10/15
MIDTERM
Day 16 Wed 10/16
Engines and Fridges
Heat Engines
Other views of the Second Law
Day 17 Thurs 10/17
Changing entropy
Heat and Work
Using $pV$ and $TS$ Plots
Day 18 Fri 10/18
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)
HW5
Day 19 Mon 10/21
Debrief on midterm results
Thermodynamic potentials
Maxwell Relations
Thermodynamic Potentials
Maxwell relations
Work or no work? (2min42s)
Name the experiment (changing entropy)
Finding entropy review
Day 20 Tues 10/22
The Rubber Band Lab
You will be collecting data to quantify the decrease in entropy when a rubber band is isothermally stretched.
HW 6 (updated 3:40pm Mon)
Day 21 Wed 10/23
Thermodynamics Practice
Section 2.1 Schroder
Name the experiment (Maxwell relations)
Video of Feynman discussing the rubber band
Day 22 Thurs 10/24
Segway to Stat Mech
Intro to Statistical Approach
Hakonen 1994 Science Article
Day 23 Fri 10/25
The Boltzmann factor
Interstellar medium
HW 7
Day 24 Mon 10/28
Topic for Monday
Interstellar medium
Day 25 Tues 10/29
Boltzmann Statistics
HW8 (updated 5:23pm 10/28)
Day 26 Wed 10/30
Boltzmann Statistics
Water Bending
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 11/4
Final exam
7:00pm - 9:00pm on Monday evening.
Additional material
Math Bits:
Internal energy on PDM
Internal Energy on the PDM (Lecture)
Not used
Math Bits:
Cycles
Cat Elevator
Math Bits
Legendre transformations
Legendre Transformations on the PDM
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
Finish Statistical mechanics of air
HW 8
Before classes start
Day 2 Thurs 9/26
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)