Interactive particle physics sandbox with 300-500 particles.
Particle Types: Protons (+1 charge, heavy), Electrons (-1 charge, light), Neutrons (0 charge, heavy). Hot particles glow red, cold ones blue.
Forces: Gravity (down), Electromagnetic (charge-based attraction/repulsion), Nuclear (nearby protons attract, close enough = fusion energy burst).
Tools: Select type and click/drag to spawn. Attractor = gravity well. Heat/Cool changes temperature. Use presets for quick setups.
Fusion: Pack protons close at high temperature = new neutron + energy blast + score!