NOVA scienceNOW

What caused the greatest mass extinction nearly 250 million years ago?1918 Flu: The 1918 flu virus is revived and decoded in the hopes that we can learn from it before the next pandemic.Profile: Cynthia Breazeal: A look at MIT social roboticist Cynthia Breazeal.Papyrus: Can we use space-age technology to read papyri fragments that are almost 2,000 years old?

Sleep may play an important role in strengthening memories.CERN: The Large Hadron Collider (LHC) nears completion at the international particle physics lab in Geneva, Switzerland.Emergence: Scientists try to understand a phenomenon called emergence, which allows a flock of birds or a school of fish to maintain such impressive order.Profile: Julie Schablitsky: A profile of University of Oregon archaeologist Julie Schablitsky, whose research is helping to rewrite the history of the Old West.

A paleobiologist has discovered preserved blood vessels and red blood cells in a 68-million-year-old dinosaur bone.Epigenetics: It seems that diet and lifestyle actually change the expression of our genes.Kryptos: A sculpture called Kryptos in the courtyard of CIA headquarters, contains a code that has yet to be fully broken.Profile: Arlie Petters: A look at Duke University Professor of Mathematics and Physics, and his research in the field of gravitational lensing.