On Thursday, May 10, 2012, Keck Observatory hosted a live webcast of an astronomy talk by Dr. Brian Siana of the University of California at Riverside. Below is the recording of that talk, which was delivered to a live audience at the Kahilu Theatre in Kamuela-Waimea, Hawaii.
The first galaxies had an extraordinary impact on the young universe. Their ultraviolet light destroyed nearly all of the atoms in the cosmos. This process, called reionization, had severe consequences for galaxies trying to form thereafter. Unfortunately, we have no idea how it happened. In galaxies today ultraviolet light cannot escape, so the first galaxies must have been very different from those we see today. Dr. Siana will describe the quest to detect these first galaxies and their impact on the early universe.