Скачать или смотреть Charged particles crystallizing in a central gravity field

In this simulation, particles of equal mass and opposite charge evolve in a gravity field directed to the central point of the shown region. They are generated in an annular domain just outside the shown area. They have equal probability to have positive or negative charge, so that (by the law of large numbers) there are roughly equal numbers of particles of each charge.The particles are subject to gravity, a Coulomb interaction, and viscous damping. The damping has been chosen quite strong here, to allow the particles to form a crystal-like structure. When particles of opposite charge become close to each other for a sufficiently long time, they react to form a diatomic molecule. Unlike in some previous simulations on this channel, they keep their charges after reacting. As a result, they tend to aggregate to form a large crystal, similar to NaCl salt for instance.
The particles' color depends on their charge. The background color depends on local charge, slightly averaged over space and time.
To save on computation time, particles are placed into a "hash grid", each cell of which contains between 3 and 10 particles. Then only the influence of other particles in the same or neighboring cells is taken into account for each particle.

Render time: 18 minutes 39 seconds
Compression: crf 23
Color scheme: Twilight by Bastian Bechtold
https://github.com/bastibe/twilight

Music: "Circular Beginning" by Jeremy Black‪@TRUEBLUEMUSICLTD‬

Current version of the C code used to make these animations:
https://github.com/nilsberglund-orlea...
https://www.idpoisson.fr/berglund/sof...
Some outreach articles on mathematics:
https://images.math.cnrs.fr/auteurs/n...
(in French, some with a Spanish translation)

#ions #particles #chemical_reactions