NOVA

After years of anticipation, tech giants and car manufacturers alike are now testing autonomous vehicles on public roads around the world. As ambitious innovators race to develop what they see as the next high-tech pot of gold, some experts warn there are still daunting challenges ahead, including how to train artificial intelligence to be better and safer than humans at making life-and-death decisions. How do self-driving cars work? What must computers be capable of to truly take the wheel?

Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe. But we know little about how their successors, the mammals, recovered and took over the world. Now, hidden inside ordinary-looking rocks, an astonishing trove of fossils reveals a dramatic new picture of how rat-sized creatures ballooned in size and began to evolve into the vast array of species—from cheetahs to bats to whales to humans—that rule our planet today.

Since the Dead Sea Scrolls were discovered in 1947, these fragile parchment relics have intrigued scholars, religious leaders, and profiteers alike. The 2,000-year-old scrolls include the oldest-known versions of the Hebrew Bible and hold vital clues about the birth of Christianity. While certain scrolls have survived intact, others have been ravaged by time—burnt, decayed, or torn to pieces—and remain an enigma. Now, scientists are using new technologies to read the unreadable, solve mysteries that have endured for millennia, and even discover million-dollar fakes.

Journey to Florence to discover how Leonardo da Vinci used science, from human dissections to innovative painting techniques, to create his legendary artwork. Learn why Mona Lisa's smile is so captivating - and what it took to create it.