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.

We call them 'man’s best friend', but their story is almost as old as man himself. Our very first friend in the world, they have walked by our side for over 20,000 years, helping us to hunt for food and offering us companionship and protection. Man’s First Friend is an epic new primetime documentary event that combines natural history, science and anthropology to explore the enduring relationship between humankind and dogs, how the two species have co-evolved together, where did they come from to take such a prominent position in our lives, and how did we learn to harness their unique talents.
The film takes viewers on an extraordinary journey through some of the most remote locations in the world to answers these questions and more. It highlights what dogs are capable of: from the Pariah dog in India who protects her owner’s banana plantations from daily attacks by Black-headed Monkeys; to Kenyan Bloodhounds trained to track ivory poachers. Dogs comfort us, relieving loneliness and helping us cope with old age.

Bitcoin is the world's leading virtual currency, but unlike real money, it is not backed by a government or properly regulated. Bitcoin is exchanged and held digitally by users - which is attractive to criminals selling drugs, pornography and arms. But now Bitcoin is moving into the mainstream and being openly marketed as an investment opportunity. The film investigates what Bitcoin is and what it means, going inside a Bitcoin mine in Iceland - where currency is made - and spending time with the Bitcoin millionaires of Silicon Valley.
The programme also hears from others who have been scammed out of their life savings and investors who think the cryptocurrency is an enormous scam and that the writing is on the wall. Around the world, authorities are sounding the alarm that Bitcoin is too risky - is it too late, or too crazy, to try to become a Bitcoin millionaire?

A Chapter of forgotten history. The first permanent European settlement in the United States was founded in 1565–two generations before the settlements in Jamestown and Plymouth–not by English Protestants, but by the Spanish and a melting pot of people they brought with them from Africa, Italy, Germany, Ireland and even converted Jews, who integrated almost immediately with the indigenous tribes.
The film uncovers one story of America’s past that never made it into textbooks. Follow some of America’s leading archaeologists, maritime scientists, and historians as they share the story of Florida’s earliest settlers. It’s a story that has taken more than 450 years to reveal.

The wartime contributions of five prominent Hollywood film directors during World War II are profiled. The documentary focuses on five directors – John Ford, William Wyler, John Huston, Frank Capra, and George Stevens – whose war-related works are analysed by modern filmmakers, respectively Paul Greengrass, Steven Spielberg, Francis Ford Coppola, Guillermo del Toro, and Lawrence Kasdan. In the first episode, John Ford's The Battle of Midway was approved directly by President Franklin D. Roosevelt while Frank Capra fights to get Why We Fight made.

40,000 years ago the steppes of Eurasia were home to our closest human relative, the Neanderthals. Recent genetic and archaeological discoveries have proven that they were not the dim-witted cave dwellers we long thought they were. In fact, they were cultured, technologically savvy and more like us than we ever imagined! So why did they disappear? We accompany scientists on an exciting search for an answer to this question and come to a startling conclusion... A climate change due to a cataclysmic event.