Time travel is not forbidden by the laws of nature, but to build a time machine, we would need to understand more about those laws and how to subvert them than we do now. And every day, science does learn more. In this film Horizon meets the scientists working on the cutting edge of discovery - men and women who may discover how to build wormholes, manipulate entangled photons or build fully functioning time crystals. In short, these scientists may enable an engineer of the future to do what we have so far been only able to imagine - to build a machine that allows us travel back and forward in time at the touch of a button. It could be you! Science fiction? Watch this film.

A shockingly candid examination of how a street dealer can rise to cartel lord with relative ease, How to Make Money Selling Drugs is an insider's guide to the violent but extremely lucrative drug industry. Told from the perspective of former drug dealers, and featuring interviews with rights advocates Russell Simmons, Susan Sarandon, and David Simon, the film gives you the lessons you need to start your own drug empire while exposing the corruption behind the "war on drugs".

Angela Rippon and Dr Chris van Tulleken travel the world in search of the latest science that could help us all stay young and healthy for longer. They investigate the best ways to help both our bodies and brains age better. Up first is the body, and Angela travels to Germany to join a groundbreaking study which reveals the exercise that holds off ageing the most. Chris visits America to find out about the unexpected diet that can add years to our lives. And in Ecuador we meet a seventeen-year-old who looks like a child to discover how scientists hope he may hold the key to preventing the diseases of ageing.

This episode explores what can give brains a boost. In America, Angela tries out a new treatment that's proven to help memory and concentration. In Japan, a remarkable 100-year-old reveals the colourful foods that keep minds more active. Plus Chris discovers the best exercise we can do for our brains. At the cutting-edge of science, discover how injections of young people's blood may help beat dementia.

The rainforest is home to more species of plants and animals than any other habitat on the planet. But for humans, life there is not as easy as it looks. Life in the trees requires great skill, ingenuity and sheer bravery. The Matis of Brazil carve 4-metre-long blow-pipes to hunt monkeys - in near total silence. Deep in the Congo forests, Tete defies death by scaling a giant tree using nothing more than a liana vine, and he must then negotiate an angry swarm of bees - all to collect honey for his family. Three children from Venezuela's Piaroa tribe venture deep into the jungle to hunt tarantulas - to toast for lunch! In West Papua the Korowai tribe show-off their engineering skills by building a high-rise home 35 metres up in the tree tops. Most memorable of all, in Brazil we join a unique monitoring flight in search an un-contacted tribe...

The film the tells the life of Jamaican sprinter and three times Olympic gold medalist and World Record holder for 100m, 200m and 4x100m, Usain Bolt, the fastest man in recorded human history. It describes Bolt's journey in winning nine gold medals and the incidents surrounding the Olympic titles. Featuring interviews with famous athletes like Pelé, Neymar, and Serena Williams, the film examines multiple world-record holder Bolt's rise to dominance and the the legacy of the fastest man ever timed.