Rational and irrational ratios

An ancient Greek philosopher, Pythagorus, believed that beauty, whether in musical harmony or architectural balance, as exemplified by the Parthenon, was associated with the ratio of small integers. His followers elevated the concept into a universal principle with religious significance. In the modern world, ratios are used widely in obstetrics and other areas of medicine. This, too, may be driven by esthetic and metaphysical considerations...