Computer simulations are a powerful and important tool for understanding the cosmos. A detailed simulation can provide a means for understanding processes which occur on such long time scales (millions or even billions of years) that it is not possible to to observe these events in the universe. Cosmological simulations are used to study galaxy collisions and also the formation of large scale structure in the universe. The introductory lesson below assumes no prior background in astronomy. The advanced lesson requires experience in building computer programs from source code.
Note: The Galaxy Crash applet is no longer available online. See this link to download the code: http://burro.case.edu/JavaLab/
Galaxy Crash lesson
Run the Galaxy Crash applet and try the suggestions in the Lab section.
Galaxy Crash"This is an interactive java applet which allows you to model galaxy collisions on your own computer. With this applet you can study how galaxies collide and merge gravitationally and how the effects of the collision depend on the properties of the galaxies. You can also recreate collisions between real interacting galaxies observed in the sky."
GADGET was developed from 2000-2005 to run cosmological simulations on massively parallel computers with distributed memory. This older software was selected for this resource due to the fact that the example programs can now be run on a typical personal computer.
cuda-gadget - "A modified version of GADGET-2 (Springel 2005) that computes tree forces on GPUs using the CUDA programming interface. Based on G2X by Carsten Frigaard." Version of GADGET-2 for w:GPU hardware.
Haroz, Steve; Heitmann, Katrin (Sept.-Oct. 2008). "Seeing the Difference between Cosmological Simulations". IEEE Computer Graphics and Applications28 (5): 37-45. doi:10.1109/MCG.2008.101. "Visualizing the time-variant results of a simulation can help scientists see patterns that would be difficult to find using only statistics. Furthermore, visualizing the differences between multiple simulations can let scientists directly analyze the simulations' consistency. In this article, we describe our interactive application for viewing the differences between multiple time-variant cosmological simulations."