In this episode of NOVA scienceNOW, journey back in time to the birth of our solar system to examine whether the key to our planet's existence might have been the explosive shockwave of an ancient supernova. Meet a chemist who has yielded a new kind of "recipe" for natural processes to assemble and create the building blocks of life. And see how the head louse, a creepy critter that's been sucking our blood for millions of years, is offering clues about our evolution. Finally, meet neuroscientist André Fenton, who is looking into erasing painful memories with an injection.
In a powerful conclusion, Brian pieces together this story of creation that started with what Einstein called the 'happiest thought of his life' - the moment that he realised that gravity was far stranger than anyone had imagined. In an incredible experiment inside the largest vacuum chamber, Brian reveals how Einstein formulated a new theory of gravity, which ultimately took us back to the big bang. And how in doing so, we humans found our true place in space and time.
Dr Alice Roberts asks one of the great questions about our species: are we still evolving? There's no doubt that we're a product of millions of years of evolution. But thanks to modern technology and medicine, did we escape Darwin's law of the survival of the fittest? Alice follows a trail of clues from ancient human bones to studies of remarkable people living in the most inhospitable parts of the planet and the frontiers of genetic research, to discover if we are still evolving - and where we might be heading.