# N-Body Orbits

An unusual 7-body orbit for gravitationally interacting particles.

N-Body solves the gravitation n-body problem for gravitationally interacting particles. The solution of this problem has inspired and challenged physicists and mathematicians for centuries and few solutions for N>2 are known. The three-body orbit shown in this model was discovered by Moore in 1993 and proved to be stable by Chenciner and Montgomery in 2000. Other unusual N-body orbits have since been found although all orbits with N> 3 are unstable (and chaotic) and sooner or later the trajectories will fly diverge and the choreography will break.

The initial-condition data for N>4 has been kindly provided by Carles Simó, UAB, Spain.

## References:

The N-Body Orbits model is designed to teach Ejs modeling. Right click within the simulation to examine this model in the Ejs modeling and authoring tool. See:

- "Modeling Physics with Easy Java Simulations" by Wolfgang Christian and Francisco Esquembre, The Physics Teacher, November 2007, 45 (8), pp. 475-480.

The Easy Java Simulations (EJS) documentation can be downloaded from the ComPADRE Open Source Physics collection and from the Ejs website.

### Note:

This simulation was created by Wolfgang Christian using the Easy Java Simulations (Ejs) modeling tool. You can examine and modify this simulation if you have Ejs installed by right-clicking within a plot and selecting "Open Ejs Model" from the pop-up menu. Information about Ejs is available at: <http://www.um.es/fem/Ejs/>.