Sept 7 Cafe – Watching the universe grow up

How did the first generation of stars and galaxies form in our Universe? Astronomers don’t know. They have ideas, to be sure, which are hard to confirm with observations because prior to the formation of the first stars and galaxies, it’s not clear what they can look at! In the last few years, much progress has been made in trying to detect radio waves from hydrogen atoms that existed in the early Universe. The existence of hydrogen precedes the formation of the first stars and galaxies, and therefore allows direct observations of the formation process. This new technique (known as “21cm cosmology”) has yet to become a standard tool in the astronomical community. Join Adrian Liu for a “sneak preview” of what will come in the next few years, as 21cm cosmology revolutionizes our understanding of how our present Universe—with its majestic astronomical patterns consisting of mature stars, galaxies, and even larger objects—came to be.