Wayne Hu

Key Concepts:

The field of cosmology has experienced an explosion of activity since the discovery of ripples in the energy of the primordial light of the big bang. Cosmology is the study of the origin, evolution, and fate of objects in the observable universe. These include galaxies like our Milky Way, a vast collection of stars spanning many thousands of light years. The key to the birth and evolution of such objects lies in the primordial ripples observed through light shining through from the early universe.

Basic Principles

Key Concepts:

As cosmologists, the main paradigms we work under are known (rather inapproprately) as the big-bang model for the global evolution of the universe and the gravitational instability paragdigm for the formation of objects or structure in the universe.

The big bang model says that the universe began hot and dense but is expanding and cooling.

The gravitational instability models says: we know large masses like the earth attract, for example by the fact that you remain on the surface of the earth rather than flung off of it as it spins, like water off a wet dog. Even a small mass attracts, so that small ripples in the mass density early on in the history of the universe can grow into the galaxies we see today in the night sky.

Based on a public talk presented at the IAS, October 25, 1996.
Viewgraphs for the talk are available as a 3MB PDF file. Use of this material is granted but please cite this site and its author as the source.

Post WMAP update of this talk available as a 34(WARNING!!!) MB PDF file or a more managable 2 MB PDF file [Hu & White, Sci. Am., 290 44 (2004)]