Orbit

Orbit is a program that shows the effects of gravity on bodies in space. The program is fully documented, comes with several example solar systems, is free and open source. Version 1.3.4 fixes lots of bugs, is faster, and allows you to see information about each system and the bodies in it on the fly. The flakiness of the animation has been fixed. It is now possible to make collision elastic. Author: Aaron Golden System Requirements: MacOS 7.5 and up License: Absolutely Free + Open Source :) Previous Updates: Version 1.2.8 is a leap ahead in all aspects of the program. It is now possible to save and open files from the program (without using the finder). The program runs much, much faster, and the blinking of the animation has been eliminated. It is now possible to make a planet stationary. It won't move no matter what. You can get some cool effects with this. As always, I added in a couple more systems for you to check out. Version 1.2.9 has cooler graphics, is faster, and fixes the bugs that made the tracking option get messed up sometimes. It also includes preferences. The new options are: Show about window on startup Show open dialog on startup Use a black background Draw a grid Version 1.3 fixes a couple bugs having to do with conservation of momentum and collisions between planets. The documentation has been updated and is more comprehensive. It is now possible to specify the radius of a body (instead of basing it on mass).