← Eris

Anatomy of an Orbit

The cobweb on the left is a single trajectory of x → x² − r: bounce off the curve, across to the diagonal, repeat. Watch it spiral into a fixed point, lock onto a cycle or fill the whole interval. The Lyapunov exponent on the right turns that into one number: negative = order, positive = chaos.

…
Detected
…
λ at this r
…
Step
0

Lyapunov spectrum  λ(r) across the whole map

Where λ dips below 0 (green) the orbit is periodic; where it pokes above 0 (red) it's chaotic. The downward spikes inside the red are periodic windows, islands of order. Space play/pause.

Things to notice

Same r, same picture

In the ordered regime, change x₀ to anything and the cobweb still ends on the same cycle. The start is forgotten.

The attractor

λ = 0 at every fork

The Lyapunov curve just kisses zero at each period-doubling, then dives back down: order lost and regained.

Why it touches zero

Chaos butts up to calm

Nudge r by 0.001 at the edge of a window and a clean 3-cycle dissolves into a full chaotic smear.

Sensitive in r too