Chemistry and Biochemistry

Boltzmann 3D

Boltzmann 3D is a form of educational software offered by the BYU Department of Chemistry & Biochemistry. Written in Java, with OpenGL graphics libraries and Windows, Mac, and Linux options, Boltzmann 3D is a kinetic theory demonstrator that visually illustrates principles of kinetic theory on your computer screen. 


                                    Boltzmann 3D 3-D arena rendering                                Boltzmann 3D 2-D arena rendering

General Information

Boltzmann 3D is named for Austrian physicist Ludwig Boltzmann, who developed much of the theory of entropy and statistical mechanics. The Boltzmann distribution for energy and the Maxwell-Boltzmann distribution for velocity likewise carry his name. He also invented a now-famous and common equation to describe the approach of a system to equilibrium. Today, however, Boltzmann is best-known for his definition of entropy in terms of the logarithm of the number of microstates. This equation (S = klnW; S= = entropy, k = proportionality constant, and W = number of microstates) is carved on his tomb. K, called Boltzmann's constant, may be mutiplied with Avogadro's number to reach the universal gas constant, R. Thus is Boltzmann's constant is the gas constant per molecule. Thus is Boltzmann immortalized in the history of the human understanding of chemistry.

Boltzmann 3D deals with visual illustrations of Boltzmann-like problems. Boltzmann 3D may be used as a classroom demonstrator of molecular motion if the program is ran on a computer linked to a classroom projector. Boltzmann 3D may also be used as a hands-on activity for students trying to understand how molecular motion leads to macroscopic properties like chemical reaction rates, gas pressure, vapor pressure, diffusion, effusion, thermal transport, and more. (Suggestions for more uses are included in the documentation below.)

Read on for instructions about installing and using Boltzmann 3D.

Contact Information

Technical questions, concerns, and comments about Boltzmann 3D may be directed to

Installing Boltzmann 3D

Click here to try the beta version 3.0 (May 2013). The link will download a Java Web Start application. Open the application to start Boltzmann 3D. You will need to agree to let the application run and agree to let it install the graphics library (LWJGL). New features in version 3.0 include square wells and the ability to simulate more than two particle types.

Settings files for common simulations can be downloaded here.

To download the latest version of Boltzmann 3D, follow the instructions below appropriate to your operating system. The current version, 2.49, was released in August 2009.

  1. Downloading with Microsoft Windows:
    1. Download the current version of the Java2 runtime environment by clicking on Select that the free download option.
    2. Ensure that you have updated OpenGL graphics libraries for your video card by updating the video card drivers from your computer or from the video card manufacturer. 
      • Find the make and model of your video card by right-clicking on the desktop, selecting properties, selecting the "Settings" tab, and looking under the "Display" heading. 
      • Use your Internet browser to find the manufacturer's website and driver download page.
    3. Click here to download a self-installing Windows executable file for Boltzmann 3D. Follow the file's instructions, including placing an icon on your desktop.
    4. When the installation is complete, double-click the icon. Boltzmann 3D will begin loading.
      • The interface should appear as 50 disks moving in a two-dimensional arena.
      • For instructions and tips, click on "Help" or find the help file in the directory where Boltzmann 3D was installed.
  2. Downloading with Mac:
    1. Download any software updates for your Apple device.
    2. Click here to download a .zip file containing the Boltzmann 3D application. Unzip the file and drag the application into the applications directory to install. 
    3. Double-click on "Boltzmann 3D." The program will begin loading.
      • The interface should appear as50 disks moving in a two dimensional arena.
      • For instructions or tips, click on "Help" or find the help file in the directory where Boltzmann 3D was installed.
  3. Downloading with Linux:
    1. Because Linux is open-source and video cards often vary in type, appropriate graphics drivers may need to be downloaded, recompiled, and/or tweaked before using Boltzmann 3D on a Linux platform.
    2. Verify that your computer may run Java 1.5 or above.
    3. Click here to download a Linux g-zipped .tar archive. 
    4. Extract the contents of the archive and execute the shell script "Boltzmann3D" (or "boltzmann3d").
      • java-version
      • tar xvf Boltzmann3D.tar.gz
      • cd boltzmann3d
      • ./boltzmann3d

To run Boltzmann 3D on a Power PC Mac, you will need to run an older version of Boltzmann 3D. Click here for that version.

Using Boltzmann 3D

Click here to view the Boltzmann 3D Quickstart and Troubleshooting guide for a brief introduction to the program.

Click here for in-depth Boltzmann online manual. Click here for an even more in-depth version of this manual in pdf form. This manual explains Boltzmann 3D's features and answers frequently asked questions.

Click here for an example of Boltzmann 3D by Mr. Paul Burgmayer of Great Valley High School, Malvern, PA. This example concerns molecules and pressure. This example may be freely downloaded and adapted.

Click here for an example worksheet associated with Boltzmann 3D by Dr. Randall B. Shirts of Brigham Young University, Provo, UT. This example concerns molecular motion. This example may be freely downloaded and adapted.


In 1994 — long before Boltzmann 3D was written — Dr. Randall B. Shirts of the BYU Chemistry Department produced a two-dimensional program called MotionBYU to help BYU chemistry and physics students visualize the distribution of molecular velocities. MotionBYU was programmed in TurboPascal by David L. Summers (a then-undergraduate electrical engineering student). At the time, MotionBYU was likely the first program to perform real-time particle motion simulation, especially since the program was written on recently produced Intel 486 computers that made such simulations possible.

Summers later translated MotionBYU into C++  a Windows program. The program was rechristened Boltzmann before being commercialized and distributed by Trinity Software. Eventually, the current iteration of Boltzmann, Boltzmann 3D, was written by Scott R. Burt (a current BYU faculty member who was an undergraduate when he wrote Boltzmann 3D) and Benjamin J. Lemmon (a then-undergraduate computer science major). The update was released in 2004. Boltzmann 3D outstrips earlier models in that it is programmed in Java using OpenGL graphics libraries, meaning Boltzmann 3D may be used on other platforms than Windows, includes 1D and 3D simulations, and features an improved user interface. BYU's Center for Instructional Design created the preliminary version of this updated user interface.

Copyright Information

Author: Randall B. Shirts
Department of Chemistry and Biochemistry
Brigham Young University
Provo, Utah 84602
Programmers: Scott R. Burt, Benjamin J. Lemmon
Additional programming: Jared Duke, Derek Manwaring, Aaron Stewart, Dustin Carr

Copyright 2004, 2005, 2008, 2009 by Brigham Young University, All Rights Reserved

A Poem Describing the Maxwell-Boltzmann Distribution

Heat: Hot, as ____: Cold by Roald Hoffmann (used with permission)

From Roald Hoffmann and Vivian Torrance. This poem was published in 1996 on page 46 of the magazine Chemistry Imagined, Reflections on Science, which is published by the Smithsonian Institution Press, Washington DC.

Deep in,

they're there, they're

at it all the time, it's jai

alai on the hot molecular fronton 

a bounce off walls onto the packed aleatory

dance floor where sideswipes are medium of exchange,

momentum trades sealed in swift carom sequences,

or just that quick kick in the rear, the haphaz-

ard locomotion of the warm, warm world.

But spring nights grow cold in Ithaca;

the containing walls, glass or metal,

are a jagged rough rut of tethered

masses, still vibrant, but now

retarding, in each collision,

the cooling molecules.

There, they're there,

still there,

in deep,


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Last updated 21 May 2013