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.

Zachary Quinto charts a journey to determine whether time travel is possible. He meets a man who claims to have traveled back in time due to a secret government program and a group of people living in Liverpool known as 'time slippers'.
Zachary makes a visit to the CERN headquarters in Geneva, where he attempts to understand the origins of the universe and the dimension of time. Equipped with this new knowledge, Zachary tests his own perception of time with an elaborate skydiving experiment to see if he can slow down time itself.

From the detection of gravitational waves generated in space over a billion years ago, to discoveries in genetics here on Earth, we've collected the most compelling science breakthroughs and advances of 2016. Thanks to magnificent, hard-working scientists and researchers around the world, science keeps marching ever forward. And this year saw some discoveries that are absolutely brimming with the promise of greater discoveries, breakthroughs and quality of life in the future.

Take a look back at many of the most fascinating science stories of 2017, a year full of stunning advancements in individual fields of study, from astronomy to biology, geology to history – when we piece these discoveries together we see the year in a new light.

Explore the myths, misconceptions, truths & amazing mysteries of our unique universe. Could life exist on Mars? Is time travel possible & does Einstein's theory of relativity support it?

Dr Hannah Fry explores a paradox at the heart of modern maths, discovered by Bertrand Russell, which undermines the very foundations of logic that all of maths is built on. These flaws suggest that maths isn't a true part of the universe but might just be a human language - fallible and imprecise. However, Hannah argues that Einstein's theoretical equations, such as E=mc2 and his theory of general relativity, are so good at predicting the universe that they must be reflecting some basic structure in it. This idea is supported by Kurt Godel, who proved that there are parts of maths that we have to take on faith.
Hannah then explores what maths can reveal about the fundamental building blocks of the universe - the subatomic, quantum world. The maths tells us that particles can exist in two states at once, and yet quantum physics is at the core of photosynthesis and therefore fundamental to most of life on earth - more evidence of discovering mathematical rules in nature. But if we accept that maths is part of the structure of the universe, there are two main problems: firstly, the two main theories that predict and describe the universe - quantum physics and general relativity - are actually incompatible; and secondly, most of the maths behind them suggests the likelihood of something even stranger - multiple universes.
We may just have to accept that the world really is weirder than we thought, and Hannah concludes that while we have invented the language of maths, the structure behind it all is something we discover. And beyond that, it is the debate about the origins of maths that has had the most profound consequences: it has truly transformed the human experience, giving us powerful new number systems and an understanding that now underpins the modern world.