Used at least as early as 400 B.C., the Golden Proportion, based on the irrational number Phi has fascinated mathematicians, artists and architects for a couple thousand years. Fibonacci is best known for his use of it in the Fibonacci sequence. Da Vinci used it extensively as did Michelangelo and countless others. But what is it, and why is it so powerful? (via An Introduction to Golden Spiral Composition Method )
