For anyone with a fascination for numbers and curiosity about what George Cardas and others are promoting.
Read "The Golden Ratio, The story of PHI, the world's most astonishing number" by Mario Livio, Broadway Books, C 2002 (available in paperback).
This book covers the golden ratio from when it was defined by Euclid, through 2000 years of historical understanding. This ratio appears widely in nature and and has been reported used in architecture, painting, analyzing the stock market, and now the design of speaker cables and optimal listening rooms. Many examples and pictures of PHI in action.
1.61803... is a remarkable and mysterious number.