Finding the First Stars and Galaxies (by Looking Where They Aren't)

Our current understanding of the universe starts with a Big Bang 13.7 billion years ago that created a simple, featureless soup of subatomic particles and ends today with a complicated structure of galaxies, stars, and planets. An interesting period of the universe’s history—the first billion or so years when the first stars and galaxies formed—has largely remained hidden from our view by its great distance from us and the lack of light from these times. In his talk, James Aguirre will discuss how we use radio waves to find the hydrogen present in this first epoch of the universe’s history, and how we are using some of the largest radio telescopes ever built to map out the faint emission from the hydrogen between galaxies to provide a picture of the universe in its earliest years.