Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
Currently, most physicists believe that only a small fraction of all the matter and energy in the universe is visible and can be seen through our most powerful telescopes. The remaining majority of the universe is thought to consist of elusive dark matter and dark energy, two substances about which we know very little. This presentation will explore the evidence in supporting the dark matter and dark energy theories and discuss some of their implications for how our universe will evolve.