It is, indeed an incredible fact that what the human mind, at its deepest and most profound, perceives as beautiful finds its realization in external nature.… What is intelligible is also beautiful.
From a lecture, "Beauty and the Quest for Beauty in Science" given at the International Symposium in recognition of Robert R. Wilson on April 27, 1979 at the Fermi National Accelerator Laboratory, Batavia, Illinois.
all the standard equations of mathematical physics can be separated and solved in Kerr geometry.
From Chandrasekhar's Nobel lecture, in his summary of his work on black holes; Republished in: D. G. Caldi, George D. Mostow (1989) Proceedings of the Gibbs Symposium: Yale University, May 15-17, 1989 p. 230
I was very fortunate to know the great astrophysicist Subrahmanyan Chandrasekhar during his last years. Chandra, as we called him, was the first to discover that general relativity implied that stars above a certain mass would collapse into what we now call a black hole. Much later, he wrote a beautiful book describing the different solutions of the equations of general relativity that describe black holes. As I got to know him, Chandra shocked me by speaking of a deep anger toward Einstein. Chandra was upset that Einstein, after inventing general relativity, had abandoned this masterpiece, leaving it to others to struggle through it.