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.
In the second episode, Professor Iain Stewart discovers how flowers have transformed our planet. He journeys to the remote islands of the South Pacific to track down the earliest flowers. In the deserts of Africa and rainforests of Vietnam, he sees how they brought brilliant colour to the most barren landscapes and sculpted the earth itself. And he learns how they drove the evolution of all animals - kick-starting our human story.
For the last 40 years, the photographer Sebastião Salgado has been travelling through the continents, in the footsteps of an ever-changing humanity. He has witnessed some of the major events of our recent history; international conflicts, starvation and exodus. He is now embarking on the discovery of pristine territories, of wild fauna and flora, and of grandiose landscapes as part of a huge photographic project, which is a tribute to the planet's beauty". Sebastião Salgado's life and work are revealed to us by his son, Juliano, who went with him during his last travels, and by Wim Wenders, himself a photographer.
Documentary-maker David Malone delves into the secrets of ocean waves. In an elegant and original film he finds that waves are not made of water, that some waves travel sideways and that the sound of the ocean comes not from water but from bubbles. Waves are not only beautiful but also profoundly important, and there is a surprising connection between the life cycle of waves and the life of human beings.
Every day our planet faces cataclysmic events that threaten our very existence. Whether from natural or man-made forces, rising from the earth or menacing from space, the world seems beset by more catastrophes than ever. Some believe the signs of the coming Apocalypse are all around us–as outlined in the bible’s most compelling book of prophecies: Revelation". And even the non-religious can’t ignore what appears to be a growing rate of globe-threatening disasters. Are we approaching a biblical “End of Times”? And if so–how will it happen? Will it come from an act of God? Or a colossal misstep of man? Get an uncomfortably close front row seat to some of the most likely apocalyptic scenarios our world faces today–and the history, both scientific and biblical, behind them.
