The discovery that everything is made from atoms has been referred to as the greatest scientific breakthrough in history. As scientists delved deep into the atom, they unravelled nature's most shocking secrets and abandoned traditional beliefs, leading to a whole new science which still underpins modern physics, chemistry and biology, and maybe even life itself. Nuclear physicist Professor Jim Al-Khalili tells the story of this discovery and the brilliant minds behind the breakthrough.

The second part of Professor Jim Al-Khalili's three-part documentary about the basic building block of our universe, the atom. He shows how, in our quest to understand the tiny atom, we unravelled the mystery of how the universe was created - a story with dramatic twists and turns, taking in world-changing discoveries like radioactivity, the atom bomb and the Big Bang, as the greatest brains of the 20th century competed to answer the biggest questions of all.

The final part of Professor Jim Al-Khalili's documentary series about the basic building block of our universe, the atom. He explores how studying the atom forced us to rethink the nature of reality itself, discovers how there might be parallel universes in which different versions of us exist and finds out that 'empty' space isn't empty at all. Al-Khalili shows how the world we think we know turns out to be a tiny sliver of an infinitely weirder universe than which we could have conceived.