An intimate and heart-warming look at the man behind the legend - as we've never seen Ali before. Told through exclusive, unprecedented access to Ali's personal archive of 'audio journals' combined with touching interviews and testimonials from his inner circle of family and friends, including his daughters, son, brother and former wife, plus legends of the boxing community including Mike Tyson, George Foreman and Gene Kilroy

Fifty years ago there were close to half-a-million lions in Africa. Today there are around 20,000. To make matters worse, lions, unlike elephants, which are far more numerous, have virtually no protection under government mandate or through international accords. This is the jumping-off point for a disturbing, well-researched and beautifully made cri de coeur from husband and wife team Dereck and Beverly Joubert, award-winning filmmakers from Botswana who have been Explorers-in-Residence at National Geographic for more than four years. Pointing to poaching as a primary threat while noting the lion's pride of place on the list for eco-tourists-an industry that brings in 200 billion dollars per year worldwide-the Jouberts build a solid case for both the moral duty we have to protect lions (as well as other threatened "big cats," tigers among them) and the economic sense such protection would make. And when one takes into account the fact that big cats are at the very top of the food chain-and that their elimination would wreak havoc on all species below them, causing a complete ecosystem collapse-the need takes on a supreme urgency.

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.

Professor Brian Cox travels from the fossils of the Burgess Shale to the sands of the oldest desert in the world to show how light holds the key to our understanding of the whole universe, including our own deepest origins. To understand how light holds the key to the story of the universe; you first have to understand its peculiar properties. Brian considers how the properties of light that lend colour to desert sands and the spectrum of a rainbow can lead to profound insights into the history and evolution of our universe. Finally, with some of the world's most fascinating fossils in hand, Brian considers how but for an apparently obscure moment in the early evolutionary history of life, all the secrets of light may have remained hidden. Because although the universe is bathed in light that carries extraordinary amounts of information about where we come from, it would have remained invisible without a crucial evolutionary development that allowed us to see. Only because of that development can we now observe, capture and contemplate the incredible wonders of the universe that we inhabit.

Comedian Ben Miller returns to his roots as a physicist to try to answer a deceptively simple question: what is one degree of temperature? His quest takes him to the frontiers of current science as he meets researchers working on the hottest and coldest temperatures in the universe, and to a lab where he experiences some of the strangest effects of quantum physics - a place where super-cooled liquids simply pass through solid glass. Plus, Ben installs his very own Met office weather station at home. Ben's investigations in this personal and passionate film highlight the importance of measurement and accuracy in the 21st century.

The BBC's definitive television history of the rise and fall of the Nazis. The Nazis - A Warning From History exposes the popular myths surrounding the rise and fall of the Third Reich. The series explores how the Nazis came to power, how they ruled, how they treated their occupied territories and, above all, how a cultured nation could be responsible for such acts of inhumanity. How could a political party as fundamentally evil and overtly racist as the Nazis come to power? This remains one of the most enigmatic questions of the last century. Acclaimed historian Laurence Rees examines what led a cultured nation at the heart of Europe to commit the atrocities it did. In so doing, he exposes popular myths and encourages understanding of the real forces that led to one of the darkest chapters in modern history. Was it simply the hypnotic power of Hitler's rhetoric? Did the Gestapo really impose themselves by terror on an unwilling population? Through interviews with witnesses and perpetrators, along with archive film and records, this six-part series unveils a more chilling reality.