Quantum tunneling is the phenomenon where a particle's wavefunction has a nonzero probability of appearing on the far side of a potential energy barrier even when the particle's energy is classically too low to climb over it — the wave simply doesn't fully vanish inside the "forbidden" region. This scene approximates that with a GPU-rendered point cloud of 6,000 particles: each one carries a fixed random "tunneling coefficient," and when it reaches the glowing barrier slab its fate (pass through or reflect) is decided once by comparing that coefficient against a probability derived from the barrier's height uniform. Reflected particles bounce back and are recolored deep violet; particles that tunnel continue on tinted cyan-white, while the barrier itself is a semi-transparent shader-driven slab whose shimmer and opacity respond live to the same height value.