Grav-Sim

The 2-body model is the simplest gravitational system.

It represents a small body in a 2-dimensional elliptical orbit around a larger body (e.g. a planet and a star).

Note that the larger body also has an elliptical orbit but doesn't move as far, a bit like an Olympic hammer thrower.

The 10-body model represents a small open cluster of same-size bodies (e.g. stars).

The bodies interact with each other at different times, giving rise to complicated 3-dimensional orbits.

The 100-body model represents a larger open cluster. You can see the stars are starting to arrange themselves in a roughly spherical manner.

Visualising the individual orbits becomes more difficult with this many bodies.

The 1,000-body model represents a small globular cluster.

It would be very messy to visualise this many individual orbits, so just the starting point is displayed.

The 10,000-body model represents a medium-sized globular cluster.

You can no longer see the stars individually in the central "core", even though they're displayed as tiny dots.

This is a challenging gravitational simulation for a desktop computer.

The 100,000-body model represents a large globular cluster.

There are now so many stars in the central core that it becomes completely white, a bit like an over-exposed photograph.

This is more-or-less the limit of what you can attempt to simulate without a supercomputer.