Time: 6:30 p.m., Wednesday, April 20th
Speaker: Xiaohan Wu
The universe at present is filled with gas that is hot and transparent to ultraviolet light. But shortly after the Big Bang, the gas was cold and opaque. How did the gas go through such a big transition in its physical state, and how did this transition affect the evolution of the universe afterwards? The answer to these questions lies in the power of the light emitted from the first stars and galaxies, which pierced through the gas in the early universe and transitioned the entire universe. Why don’t we follow the first light of the universe from the “dark ages” of the cosmos when no star existed, to the cosmic dawn when the first stars and galaxies formed. We will see how the first light fought its journey through the opaque gas in the early universe and lit everything up.