On November 25th, 1915, Einstein published his greatest work: general relativity. The theory transformed our understanding of nature's laws and the entire history of the cosmos, reaching back to the origin of time itself. Now, in celebration of the 100th anniversary of Einstein's achievement, NOVA tells the inside story of Einstein's masterpiece. The story begins with the intuitive thought experiments that set Einstein off on his quest and traces the revolution in cosmology that is still playing out in today's labs and observatories. Discover the simple but powerful ideas ...