Ian McGreer

Columbia University, PhD Candidate

First Light in the Universe

The Big Bang was the most energetic event in the history of the universe, and it left an afterglow we see covering the sky today. However, for hundreds of millions of years following this spectacular event, there were no sources of light in the universe, a period known as the Dark Ages. The spell was broken by the first stars and quasars that formed and began to illuminate their surroundings, providing the first light since the Big Bang. In the past few years, scientists have discovered distant quasars that are close to probing these dark times, and in the next decade we may find the first sources of light in the modern universe.