Many argue that flying saucers and other extra-terrestrial space ships continuously visit the earth. If that were true, what kinds of technologies would such alien spacecraft require? And do eyewitness reports of UFO sightings jibe with modern theories of how interstellar travel might be possible? Authors, astronomers and theoretical physicists weigh in with the blueprints for inertia-canceling devices, nuclear-powered craft, antimatter propulsion systems and even warp drives. Based on Einstein's theories and countless scientific studies, we'll find out how these visitors might bridge the vast distances between the stars. And if they could survive such hazardous journeys, are they flesh and blood or intelligent machines?

Volcanoes are one of nature’s most awesome and destructive forces, but they are also the life force and architect of our planet. They can raise up great mountains and create new land, or they can level cities and destroy entire civilizations. They provide a glimpse of the power of Earth’s internal heat source, without which it would have become a dead planet millions of years ago. In this episode, Iain takes us on a journey to some of the most dramatic places on Earth, starting in Ethiopia.

Beneath Yellowstone National Park, lies the biggest volcano on Earth. An eruption in the past was so big it plunged the earth into a volcanic winter that lasted years. A super-eruption would be more than millions of Hiroshima bombs going off all at once. It would be even worse than an asteroid impact: Entire cities lost beneath ash, people and animals crushed alive, power networks destroyed, sun dimmed across the globe, harvests failed, widespread famine. Could this nightmare really happen? We will use the latest scientific data to uncover the danger beneath us, as we see our planet like never before.

Our planet is one in a billion. How incredible, awe-inspiring life is driven by its natural forces - and how we can ensure humans become a force for good. David Attenborough narrates a series revealing how the forces of nature drive, shape and support the Earth's great diversity of life.
The first edition examines volcanoes, which responsible for both for the planet's breathable atmosphere and the oceans, but are also the architects of the planet, with over 80% of the Earth's surface being the result of magma bursting up from the molten interior - providing a platform for life.

Imagine a world where infinite copies of you are playing out every storyline of your life. It sounds like a plot stolen straight from Hollywood, but far from it. This is the multiverse. Until very recently the whole idea of the multiverse was dismissed as a fantasy, but now this strangest of ideas is at the cutting edge of science. And for a growing number of scientists, the multiverse is the only way we will ever truly make sense of the world we are in. Do multiple universes exist? And if so, which one are we actually in?" Imagine a world where dinosaurs still walk the earth. A world where the Germans won World War II and you are president of the United States. Imagine a world where the laws of physics no longer apply.

Iain sets sail on one of the fastest racing boats ever built to explore the story of our turbulent relationship with the wind. Travelling to iconic locations including the Sahara desert, the coast of West Africa and the South Pacific, Iain discovers how people have exploited the power of the wind for thousands of years. The wind is a force which at first sight appears chaotic. But the patterns that lie within the atmosphere have shaped the destiny of continents, and lie at the heart of some of the greatest turning points in human history.