What is the universe made of? If you answered stars, planets, gas and dust, you'd be dead wrong. Thirty years ago, scientists first realized that some unknown dark substance was affecting the way galaxies moved. Today, they think there must be five times our understanding of the universe and the nature of reality itself has drastically changed over the last 100 years - and it's on the verge of another seismic shift. In a 17-mile-long tunnel buried 570 feet beneath the Franco-Swiss border, the world's largest and most powerful atom smasher, the Large Hadron Collider, is powering up. Its goal is nothing less than recreating the first instants of creation, when the universe was unimaginably hot and long-extinct forms of matter sizzled and cooled into stars, planets, and ultimately, us. These incredibly small and exotic particles hold the keys to the greatest mysteries of the universe. What we find could validate our long-held theories about how the world works and what we are made of -- or, all of our notions about the essence of what is real will fall apart.

Every cosmologist and astronomer agrees: our Universe is 13.7 billion years old. Using cutting-edge technology, scientists are now able to take a snapshot of the Universe a mere heartbeat after its birth. Armed with hypersensitive satellites, astronomers look back in time to the very moment of creation, when all the matter in the Universe exploded into existence. It is here that we uncover an unsolved mystery as old as time itself -- if the Universe was born, where did it come from? Meet the leading scientists who have now discovered what they believe to be the origin of our Universe, and a window into the time before time.

Where did everything in our universe come from? How did it all begin? For nearly a hundred years, we thought we had the answer: a big bang some 14 billion years ago. But now some scientists believe that was not really the beginning; our universe may have had a life before this violent moment of creation. Take the ultimate trip into the unknown, to explore a dizzying world of cosmic bounces, rips and multiple universes, and finds out what happened before the big bang. Horizon takes the ultimate trip into the unknown, to explore a dizzying world of cosmic bounces, rips and multiple universes, and finds out what happened before the big bang.

Brian takes a fresh look at the concept of gravity, revealing it to be far more than just the force that makes things fall to the ground.
In the last three years, we've made profound discoveries about the nature of gravity and the way it behaves, and how this relates to the origin of the universe and strange things like black holes. Our theory of gravity has become the attempt to understand the nature of space and time.

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.

There is a strange and mysterious world that surrounds us, a world largely hidden from our senses. The quest to explain the true nature of reality is one of the great scientific detective stories. Clues have been pieced together from deep within the atom, from the event horizon of black holes, and from the far reaches of the cosmos. It may be that we are part of a cosmic hologram, projected from the edge of the universe. Or that we exist in an infinity of parallel worlds. Your reality may never look quite the same again.