Stop Planets
Dynamical Astronomy JavaLab

Welcome to the Dynamical Astronomy Javalab at Case Western Reserve University's Department of Astronomy. Here you will find a variety of Java applets which explore the motion of planets, stars, and galaxies. Each applet comes with background information on the pertinent astrophysics, a technical description of what's being calculated, and links to more information both on the web and in the popular and scientific literature.

Why are we doing this? One of the more difficult facets of astronomy is that astronomers rarely have the opportunity to run hands-on experiments with the objects they study. We can't change the orbits of stars we observe, we can't smash galaxies together -- all we can do is watch what's already happening. And there's the other problem -- astronomical timescales. It often takes millions or billions of years for stars or galaxies to move along their orbits, so we can't even watch a single star or galaxy travel through space. It makes doing "dynamical astrophysics" difficult.

Instead, what astronomers do is use computer simulations to model planets, stars, and galaxies, using the computer as a time machine to watch how the universe evolves. We can compress a billion years of time into a few short minutes of computing time and watch stars move on their orbits, study star clusters diffusing apart, or see entire galaxies colliding and merging. Using computers, we can turn astronomy into a experimental science, and play a more active role in studying stars and galaxies.

With the speed of personal computers ever increasing, many of these computer models can now be done (albeit in a simpler fashion) in real time on the desktop. That's where we're going with this javalab -- giving people an opportunity to study the dynamical universe without having to use supercomputers, slog through difficult computer programs, or undertake tedious data analysis.

The applets are aimed at a variety of levels -- some are appropriate for everyone, while others are more specialized and assume more prior knowledge of astronomy and physics. Many of them can even be useful to professional astronomers by acting as preliminary groundwork for more sophisticated calculations. The physics here is as real as we can make it and still deliver fast computing times (do you really want to wait a week for your calculation to run?).

Go to the applets page and try them out. Happy computing!

Professor Chris Mihos
Department of Astronomy
Case Western Reserve University