Ladder

Golden ratio — the ladder

2 distinct arguments against one idea, from the one that introduces it to the one that assumes the rest.
  1. The whirling squares. Squares with Fibonacci sides 1, 1, 2, 3, 5, 8, 13, each attached to the long side of what came before. They fill a 13 by 21 rectangle exactly.

    The rectangle that eats itself

    Cut a square off a golden rectangle and what is left is a golden rectangle. That single property is the whole of the golden ratio, and it explains both what the number really does and most of what is wrongly claimed for it.

    rung 1 · geometry
  2. Rotating by φ − 1 of a turn, 21 times. Points on a circle produced by repeatedly turning through the same angle.

    Three gaps and no more

    Turn a circle by the same irrational angle over and over. The points never repeat and never settle, and yet at every single stage the gaps they leave take at most three different lengths — never four, at any number of steps, for any angle.

    rung 2 · dynamics

All ladders