Is Time Travel Possible? Stephen Hawking explores the world's favourite scientific 'what if?' He explores all the possibilities, warping the very fabric of time and space as he goes. From killing your grandfather to riding a black hole, we learn the pitfalls and the prospects for a technology that could quite literally, change everything.

Our universe is at war. The universe is a very violent and deadly place. Entire galaxies fight to the death. Only the strongest survive. If a galaxy wants to stay alive, it has to feed on other galaxies. Our own galaxy also fights for survival. These battles are how galaxies live, grow, and die. These collisions got us to where we are today, and they're going to determine the future of the universe.

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.

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.

Discover the Eras of the Universe and the answer to this big question: When Will Time End? Once the notion that the universe started with a rapid inflation nicknamed the Big Bang became accepted by the majority of scientists, many possible fates are predicted by rival scientific hypotheses, including futures of both finite and infinite duration. The ultimate fate of the universe is dependent on the shape of the universe and what role Dark energy will play as the universe ages.

Black Holes are one of the most destructive forces in the universe, capable of tearing a planet apart and swallowing an entire star. Yet scientists now believe they could hold the key to answering the ultimate question - what was there before the Big Bang? The trouble is that researching them is next to impossible. Black holes are by definition invisible and there's no scientific theory able to explain them. Meet the astronomers attempting to image a black hole for the very first time and the theoretical physicists getting ever closer to unlocking their mysteries. It's a story that takes us into the heart of a black hole and to the very edge of what we think we know about the universe.