Description:

Physics::Particles is a facility to simulate movements of a small
number of particles under a small number of forces that every particle
excerts on the others. Complexity increases with particles X particles
X forces, so that is why the number of particles should be low.

In the context of this module, a particle is no more or less than a
set of attributes like position, velocity, mass, and charge. The
example code and test cases that come with the distribution simulate
the inner solar system showing that when your scale is large enough,
planets and stars may well be approximated as particles. (As a matter
of fact, in the case of gravity, if the planet's shape was a sphere,
the force of gravity outside the planet would always be its mass times
the mass of the body it excerts the force on times the gravitational
constant divided by the distance squared.)

Simulation of microscopic particles is a bit more difficult due to
floating point arithmetics on extremely small values. You will need to
choose your constant factors wisely.