Concept
Self similarity
2 essays name this object, across 2 fields. What follows is each of them, and the objects they name alongside it.
Pascal's triangle, in two colours
Shade the odd numbers in Pascal's triangle and a fractal appears. Nothing was designed to produce it, and the same shape arrives independently from a completely different construction.
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.
Named alongside it
The objects these essays reach for when they reach for this one.
RecursionBinomial coefficientContinued fractionsFibonacciGolden ratioKummer's theoremLogarithmic spiralLucas' theoremParityPhyllotaxisPrimesSierpiński triangle