| planets(1) | General Commands Manual | planets(1) |
planets - Gravitational simulation of planetary bodies
Planets is a simple interactive program for playing with simulations of planetary systems. It is great teaching tool for understanding how gravitation works on a planetary level.
The user interface is aimed at being simple enough for a fairly young kid can get some joy of it. There's also a special kid-mode aimed at very young children which grabs the focus and converts key banging into lots of random planets.
Planets uses a fourth-order runge-kutta approximation for the simulation itself. Planet bouncing is achieved by adding a repulsive force to planets at close quarters. Planets is fairly flexible: you can change the gravitational constant, the time-slice of the simulation, and even the exponent used in the gravitational law. Universes are saved in the ~/.planets directory, and are simple human readable and editable files.
Currently bouncing doesn't work very well unless you make the time-slice quite small. Ideally, it would be nice to have a billiard-style bounce system, but it's not clear how to do this accurately in the presence of a strong gravitational field.
Planets was written by Yaron M. Minsky <yminsky@cs.cornell.edu> as a gift for his nephew, Eyal Minsky-Fenick.
This manpage was contributed originally by Martin Pitt <martin@piware.de> for the Debian GNU/Linux system (but may be used by others).
| April 20, 2003 |