Fibonacci spirals emerge from optimal packing via irrational angle
Golden angle: 137.508° = 360°/φ²
Plant primordia grow at fixed divergence angle φ from center: position (r, α) = (c√n, n×φ).
Golden angle φ_g = 360°(1 − 1/φ) ≈ 137.508° (φ = golden ratio).
Because φ_g is the "most irrational" number, it fills space most uniformly, generating
the Fibonacci spiral arms (8, 13, 21, 34...) visible in sunflowers and pine cones.
Drag the angle slider to see Fibonacci numbers appear near 137.508° and how nearby
rational approximations create visible spoke patterns.