Astrophysics Lectures - "Probing the Dark Universe" - A Lecture by Dr. Josh Frieman

In this one-hour public lecture Josh Frieman, director of the Dark Energy Survey, presents an overview of our current knowledge of the universe and describe new experiments and observatories. Over the last two decades cosmologists have made remarkable discoveries: Only 4 percent of our universe is made of ordinary matter - atoms, molecules, etc. The other 96 percent is dark, in forms unlike anything with which we are familiar. About 25 percent is dark matter, which holds galaxies and larger-scale structures together and may be a new elementary particle. And 70 percent is thought to be dark energy, an even more mysterious entity which speeds up the expansion of the universe. Josh Frieman is senior staff scientist at the Fermilab and Professor of Astronomy and Astrophysics and member of the Kavli Institute for Cosmological Physics at the University of Chicago. The Dark Energy Survey is a collaboration of 300 scientists from 25 institutions on 3 continents, which built and uses a powerful 570-Megapixel camera on a telescope in Chile to carry out a 5-year survey of 300 million galaxies and thousands of supernovae to probe dark energy and the origin of cosmic acceleration.