This episode covers the nature of how life may have developed on Earth and the possibility of life on other planets. Tyson begins by explaining how the human development of writing systems enabled the transfer of information through generations, describing how Princess Enheduanna ca. 2280 BCE would be one of the first to sign her name to her works, and how Gilgamesh collected stories, including that of Utnapishtim documenting a great flood comparable to the story of Noah's Ark. Tyson explains how DNA similarly records information to propagate life, and postulates theories of how DNA originated on Earth, including evolution from a shallow tide pool, or from the ejecta of meteor collisions from other planets. In the latter case, Tyson explains how comparing the composition of the Nakhla meteorite in 1911 to results collected by the Viking program demonstrated that material from Mars could transit to Earth, and the ability of some microbes to survive the harsh conditions of space. With the motions of solar systems through the galaxy over billions of years, life could conceivably propagate from planet to planet in the same manner. Tyson then moves on to consider if life on other planets could exist. He explains how Project Diana performed in the 1960s showed that radio waves are able to travel in space, and that all of humanity's broadcast signals continue to radiate into space from our planet. Tyson notes that projects have since looked for similar signals potentially emanating from other solar systems. Tyson then explains that the development and lifespan of extraterrestrial civilizations must be considered for such detection to be realized. He notes that civilizations can be wiped out by cosmic events like supernovae, natural disasters such as the Toba disaster, or even self-destruct through war or other means, making probability estimates difficult. Tyson describes how elliptical galaxies, in which some of the oldest red dwarf stars exist, would offer the best chance of finding established civilizations. Tyson concludes that human intelligence properly applied should allow our species to avoid such disasters and enable us to migrate beyond the Earth before the Sun's eventual transformation into a red giant.

A journey through the dramatic and destructive years of the French Revolution, telling its history in a way not seen before - through the extraordinary story of its art. Our guide through this turbulent decade is the constantly surprising Dr Richard Clay, an art historian who has spent his life decoding the symbols of power and authority.

The use of embryonic stem cells has ignited fierce debate across the spiritual and political spectrum. But what if we could create manmade stem cells - or find super cells in adults that could forever replace embryonic cells and remove the controversy? Today, we are on the brink of a new era - an age where we may be able to cure our bodies of any illness. Stephen Hawking has spent his life exploring the mysteries of the cosmos, now there is another universe that fascinates him - the one hidden inside our bodies - our own personal galaxies of cells." Hawking takes us on a fascinating journey exploring what these wondrous and baffling mechanisms are capable of. He is joined by the scientists who are on the front lines of discovery in this field including Dr. Doris Taylor who is customizing a donor's heart with the recipient's stem cells - her goal is to revolutionize heart transplants, Dr. Paul Lu and Dr. Mark Tuszynski may have created a breakthrough that could cure paralysis, and Dr. Vincent Giampapa who believes that stem cells can be used to stem the tide of aging and create a fountain of youth.

It's a golden age for planet hunters: recently, they've discovered more than 750 planets orbiting stars beyond our sun. Some of them, like a planet called Kepler-22b, might even be able to harbor life. What would that life look like? Combining startling animation with input from expert astrobiologists, Alien Planets Revealed takes viewers on a journey of the imagination as we 'build' aliens from the ground up. What chemical building blocks will make up their genetic code? How will life get started and how will the exotic environment on a planet like Kepler-22b drive evolution? Bringing the creative power of veteran animators together with the latest discoveries in astrobiology, Alien Planets Revealed provides a glimpse of the creatures we might one day encounter beyond our solar system.

At first glance, Matthew Vandyke —a shy Baltimore native with a sheltered upbringing and a tormenting Obsessive-Compulsive Disorder diagnosis— is the last person you’d imagine on the front lines of the 2011 Libyan revolution. But after finishing grad school and escaping the U.S. for 'a crash course in manhood,' a winding path leads him just there. Motorcycling across North Africa and the Middle East and spending time as an embedded journalist in Iraq, Matthew lands in Libya, forming an unexpected kinship with a group of young men who transform his life. Matthew joins his friends in the rebel army against Gaddafi, taking up arms (and a camera). Along the way, he is captured and held in solitary confinement for six terrifying months.

Professor Jim Al-Khalili tells the electrifying story of our quest to master nature's most mysterious force - electricity. Until fairly recently, electricity was seen as a magical power, but it is now the lifeblood of the modern world and underpins every aspect of our technological advancements.Without electricity, we would be lost. This series tells of dazzling leaps of imagination and extraordinary experiments - a story of maverick geniuses who used electricity to light our cities, to communicate across the seas and through the air, to create modern industry and to give us the digital revolution. Episode one tells the story of the very first 'natural philosophers' who started to unlock the mysteries of electricity. They studied its curious link to life, built strange and powerful instruments to create it and even tamed lightning itself. It was these men who truly laid the foundations of the modern world. Electricity was without doubt a fantastical wonder. This is the story about what happened when the first real concerted effort was made to understand electricity; how we learned to create and store it, before finally creating something that enabled us to make it at will - the battery.