“Taking the baby picture of the universe”

In this talk, David Spergel, Professor of Astrophysics at Princeton University, explores observations of the cosmic microwave background (CMB) as a “baby picture” of the universe, taken just 300,000 years after the Big Bang. He details the findings from missions like WMAP and the expected advances with the Planck satellite to better constrain fundamental cosmological parameters. Spergel also raises key questions about the cosmos: What happened in the universe’s earliest moments? How does dark energy influence its evolution? And what were the properties of the first stars?

This lecture, delivered in October 2011, is part of the astrophysics series ‘The Science of the Cosmos, the Science in the Cosmos’, tackles the fundamental questions in contemporary astrophysics.Why, at some point some 13 billion years ago, did a tiny, hot universe begin expanding in a Big Bang? The birth of the universe, as well as the formation of stars and planets, are explored in the first edition.