Physics sandbox: build a force field

Drop attractors, repulsors and vortices anywhere on the field and 5,000 tracer particles respond to all of them at once. The background shows the combined potential and the vortex streamlines, so you can see superposition at work. Presets build galaxies, binary stars and spiral arms in one click.

This interactive simulation runs in your browser with WebGL. Free, no account needed.

What you can explore

Sources

Attractors pull particles in like gravity, repulsors push them away, and clockwise or anticlockwise vortices swirl them around. Every source adds to the field independently: the principle of superposition.

Presets

Galaxy, binary star, dipole, vortex ring, spiral arms and chaos presets show how a few simple sources combine into rich, recognisable structures.

Key equations

  • F = Σ Gᵢ r̂ / r² + Γᵢ r̂⊥ / r²

Curriculum

AQA A-level physics 3.7 (fields), IB Physics D.1–D.2.

Common questions

What is the principle of superposition for fields?

The total field at any point is the vector sum of the fields from each source acting alone. The sandbox adds every source’s pull at every particle, every frame.

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