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.
The standard model of cosmology has some puzzles/problems such as the
cosmological constant problem and the horizon problem which according to
many stem from our lack of understanding of the very early universe. This in turn means that almost none of the theories of quantum gravity are at a
stage where anything substantial can be said about observational cosmology.
In the past few years Causal Set theory has proved itself different in this
case where a possible solution to the Cosmological constant problem was