Gravitational/Electric field

This simulation shows the vector field defined as  This field is associated with gravity and electrostatic attraction. The gravitational field around a planet and the electric field around a single point charge are similar to this field. The field points towards the origin, when , and is inversely proportional to the square of the distance from the origin. Activate the box 'Particles' to start the animation. You can also change the values of by activating the box 'Field'.