A special forum on critical issues in cosmology in celebraton of Princeton University's 250th birthday.The proceedings of this conference, held as part of Princeton University's 250th birthday celebrations, features lectures and discussions by many of the world's leading scientists on the status and future of modern cosmology.The volume offers the non-specialist a fascinating insight into the current status of cosmology and the issues of contention at the research frontiers of the science. It constitutes the proceedings of a special conference, held as part of Princeton University's 250 birthday celebrations, featuring lectures and discussions by many of the world's leading scientists on the status and future of modern cosmology. The volume is based on the format of a series of debates in which a range of conventional wisdom is reviewed, defended and critcised by renowned specialists in each field.The technical level of the volume is accessible to a very broad audience of non-specialists. This innovative exchange of ideas at the cutting edge of cosmology therefore offers an unusual opportunity for the average reader to savour the excitement of probing into the ultimate secrets of the universe.