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's evidence that dark matter makes up 85% of all the matter in the universe. We can see dark matter holding galaxies together and ripping other structures apart, we even see it bending light. Dark matter itself has been around since the beginning of the universe. Without dark matter, we wouldn't be here. But if you can't see dark matter and if you can't touch it, does it really exist?
Dark Matter is thought to be the cosmic glue that holds the universe together, yet the search for it continues to eluded scientists today.

Cosmic rays capable of destroying human DNA are hurtling through outer space like subatomic bullets, causing space crews radiation damage.
Cosmic rays are intergalactic alien interlopers on our Milky Way. But the source of their power is a mystery. Are they coming from other galaxies? Are they coming from things in between the galaxies? Where do cosmic rays come from? Truth is, the most powerful ones, we haven't got a clue. The race is on to solve the mystery of the fastest particles in the universe.