It has too many answers. Small is beautiful. Black is beautiful. Sunsets, Cindy Crawford and the Pythagorean theorem are beautiful as well. Defining it is difficult, perhaps impossible, yet beauty is a real force that stabs us when we see it.
Numbers have their own chillier sort of beauty.
He was sure he knew what beauty was. Most of them believe, as Charles Baudelaire insisted 150 years ago, that what humans see as beautiful is not permanent and ageless, but changes with the times. Many modern artists have happily rejected traditional views of beauty, agreeing that to label something beautiful is to pretty much condemn it as trivial and false. The collector Duncan Phillips did not seek the beautiful in either human bodies or Euclidean geometries. What moved him most was color.