Science

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.

While scientists have previously theorised about a “Big Crunch” where the universe retracts back to its original size, the discovery of Dark Matter and Dark Energy has placed that hypothesis on the backburner. Some astronomers now believe that if Dark Matter offsets Dark Energy then as the universe slowly expands, stars will gradually fade, running out of fuel and leading to a dark, cold and lifeless universe. Others hypothesise a much more violent end where Dark Energy continues to expand the universe at a greater and greater speed. Stronger than gravity, Dark Energy would pull apart everything down to the fundamental particles – the universe’s very fibres. While the universe’s end may be 50 billion years away, great leaps in science will continue to alter how we believe the universe was formed – and how it will end.

New Zealand - 850 years ago New Zealand was the last major land mass to be discovered and colonised by humans. A mere 850 years ago, Polynesian seafarers arrived in a land with no terrestrial mammals. New Zealand was a land of birds, and its avian rulers were giants: huge herbivorous moas were hunted by Haast's eagle - the largest eagle the world has ever seen. But within the space of only 100-400 years, the eagle, all the moas and over 20 other species of birds were gone. Had mankind become the monster?

Bitcoin is a peer-to-peer monetary system in which all transaction records are public. Participants can use its open-source software to transfer virtual currency to one another as easily as they might send an email. Bitcoin opens an uncharted world of new possibilities to explore. We'll follow the stories of entrepreneurs and startups that are helping shape the new financial frontier. We'll look at the competitive mining market and the various subcultures within the Bitcoin community." You'll encounter a variety of characters and opinions as we examine the social and political impact of an open-source digital currency. Will the rise of Bitcoin bring a monetary paradigm shift that will forever change the world? Supposedly invented by a mysterious Japanese man named Satoshi Nakamoto (whose current whereabouts are unknown). Because it is designed to have an absolute ceiling of 21 million Bitcoins in circulation (not anticipated until 2040), and the system has no central depository or administrative authority, it has great appeal to libertarians and others who seek alternatives to a perceived corrupt, manipulative banking infrastructure and excessive government regulations. Its low processing fees compared with those of mainstream credit-card companies also hold considerable allure for merchants.

We move around in space, but we are stuck in a prison of time moving ever forwards. Einstein said, 'The distinction between past, present and future is only a stubbornly persistent illusion.' Is our experience of the ticking clock merely a trick of the mind? Could science ever make the clock move backwards? Experiments in quantum physics are showing that the future influences the present: what happens later limits the choices we think we have now. The laws of physics say visiting or talking to ourselves in the past is possible – but changing history once we get there is not.

Travel from the inner solar system to the Kuiper Belt and explore the moons surrounding the planets of the solar system. Many of these moons that were once unknown are now on the cutting edge of astronomical study. Some burst with volcanic fury another spews icy geysers and others offer the possibility of alien life. Are these strange worlds simply hostile environments unfit for humans or do other possibilities exist? Cutting-edge computer graphics are used to bring the universe down to earth and to imagine what kind of life forms might evolve in alien atmospheres.