Nearly 100 years ago, Carnegie astronomer Edwin Hubble made two truly revolutionary discoveries: First that our Milky Way was only one of many galaxies in a vast universe, and second that the farther these galaxies were from us, the faster they appeared to be moving away from us. The ratio between these speeds and distances, which we now call the Hubble Constant, is a fundamental quantity that sets the scale for the size and age of the entire cosmos. For decades, its precise value has been a source of contention among astronomers. Even today, with the most-powerful telescopes at our disposal, tension between different groups remains. Dr. Burns will cover the history of Hubble’s troublesome constant and how we are trying to pin it down.
Dr. Chris Burns: Research Associate, Carnegie Observatories, Carnegie Institution for Science