The frequency of appearance of the Golden Ratio in nature implies its importance as a cosmological constant and sign of being fundamental characteristic of the Universe. Except than Leonardo Da Vinci's Monalisa it appears on the sunflower seed head, flower petals, pinecones, pineapple, tree branches, shell, hurricane, tornado, ocean wave, and bird's flight patterns. It is also very prominent on human body as it appears on human face, legs, arms, fingers, shoulder, height, eye-nose-lips, and all over DNA molecules and human brain as well. It is inevitable in ancient Egyptian pyramids and many of the proportions of the Greek Parthenon. But very few of us are aware of the fact that it is part and parcel for constituting black hole's entropy equations, black hole's specific heat change equation, also it appears at Komar's Mass equation of black holes and Schwarzschild-Kottler metric - for null-geodesics with maximal radial acceleration at the turning point of orbits. But here in thisbook the discussion is limited to the exhibition of mathematical aptitude of Golden Ratio - the Divine Proportion, the Cosmological Constant and the Fundamental Constant of Nature.