There are two aspects of cosmology today that make it more alluring than ever. First there is an enormous amount of data. To give just one example of how rapidly our knowledge of the structure of the universe is advancing consider galaxy surveys which map the sky. In 1985 the state-of-the-art survey was the one carried out by the Center for Astrophysics; it consisted of the positions of 1100 galaxies. Today the Sloan Digital Sky Survey and the Two Degree Field between them have recorded the 3D positions of half a million galaxies.
