Overview
This page contains a set of curricular materials and Open Source Physics Java programs that are designed to help introductory physics students understand the Second Law of Thermodynamics. The activities described in this package attempt to help students understand why one should expect the entropy of an isolated macroscopic system (one consisting of a large number of particles) to always increase. The activities also illustrate the connection between this entropy increase and the fact that thermal energy flows from hot to cold (and not vice versa). A more detailed description of the activities is given in a paper that I submitted to The Physics Teacher.
The activities consist of two main parts. The first part is a description of a hands-on "experiment" which is intended to illustrate important concepts related to entropy and the Second Law of Thermodynamics. The second part is a sequence of computer simulations that allow students to explore the Second Law more deeply and in new contexts. The computer simulations and other curricular materials are all contained within an Open Source Physics Launcher package, which runs as a stand alone Java program. This program, as well as worksheets and other materials, are available below.
Materials
The materials you will need for these activities are:
- The Statistical Interpretation of Entropy Launcher Package (available below).
- The Statistical Interpretation of Entropy Worksheets (available below).
- A spreadsheet program, or other plotting program to create a plot of the data from the experiment. A pre-formatted Excel file is available below.
- Coins: each group of students who completes the activity will need 20 coins (preferably all identical). Twenty pennies will work just fine. Other tokens can be used as well as long as they have a clearly discernable "heads" side and "tails" side. It works best if the coins are arranged in four rows of five.
- 20-sided Dice: each group will also need one 20-sided die (d20). These dice can be found in a variety of hobby and gaming stores. They are generally made of plastic and have an icosahedral shape (see image below). At the time of this writing I have found packs of 10 d20's for $4 plus shipping at http://www.hobbiesandgames.com.
Software
Download the Statistical Interpretation of Entropy software by clicking on the links below. Most users will only want the Launcher package and the Excel file. However, the source code is also available here for those who may wish to modify it (under the GNU Public License). Please note that to use the source code you will need the Open Source Physics libraries (available at http://www.compadre.org/osp/). The programs in the Statistical Interpretation of Entropy package are based on programs written by Jan Tobochnik and Peter Sibley for the OST-STP project (see http://stp.clarku.edu).
Worksheets
Worksheets that guide students through the activities can be downloaded using the links below. The worksheets are available in pdf, LaTeX source, and html formats. (If someone would like to convert these into Word I would be happy to post the resulting files here - but I don't use Word unless I am forced to do so.) The worksheets are released under the Creative Commons license (see below).
Credits
- Open Source Physics Library by Wolfgang Christian and collaborators (see http://www.compadre.org/osp/ for more details).
- Launcher and LaunchBuilder by Doug Brown.
- CoinFlipApp, IdealGas2boxApp, HeatingApp, and DemonApp by Todd Timberlake. (Note: these programs were based on programs written by Jan Tobochnik and Peter Sibley and available as part of the OSP-STP package. See http://stp.clarku.edu/ for more details.)
- All Curricular Materials by Todd Timberlake.
Copyright
The Java programs in the package are Open Source Physics (OSP) programs and are freely distributable under the GNU GPL license. For more information about the Open Source Physics project visit http://www.compadre.org/osp/.

All of the curricular materials (including the narratives in the Launcher package) are copyrighted by Todd Timberlake and are licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. You may modify and redistribute these materials for non-commercial use as long as you clearly cite Todd Timberlake as the original author and release the materials under the same license.
Presentations On This Material
I gave a poster presentation on this material entitled "An active introduction to entropy and irreversibility for liberal arts students" at the 2009 Summer Meeting of the American Association of Physics Teachers, University of Michigan, July 2009. Click here for a
PDF of my poster (956 KB).
Todd K. Timberlake (ttimberlake@berry.edu)