Hans Kristian Eriksen: "Isotropy and the Cosmic Microwave Background"

One of the most important assumptions in cosmology is that of the Cosmological Principle: On large scales the universe is isotropic and homogenous. This principle is based on significant observational evidence, of which the most important source is the Cosmic Microwave Background (CMB). In this talk I will review this topic, starting with the earliest detection of the CMB by Penzias and Wilson, to the discovery of anistropies by COBE-DMR, and ending up with some very recent (and highly surprising!) results from the current WMAP data -- is the universe really as isotropic and simple as theorists want us to believe?