Inside the world-renowned physics laboratory Fermilab, a team of scientists are constructing an audacious experiment to hunt for a mysterious new ‘ghost’ neutrino. If they find it, this could transform our understanding of the nature and fabric of our universe. The problem is, these tiny particles are almost impossible to detect.
Elsewhere, physicists conduct experiments in some of the most extreme environments on the planet: from deep mine shafts in South Dakota to vast ice fields at the South Pole. In these unlikely places supersized neutrino detectors hope to unlock the universe’s deepest secrets. Could neutrinos overturn the most precise theory of particle physics that humans have ever written down? Could they even be a link to a hidden realm of new particles that permeate the cosmos – so called dark matter? Scientists at Fermilab are edging towards the truth.

In this episode, Michael demonstrates how our society is built on our search to find the answer to what makes up everything in the material world. This is a story that moves from the secret labs of the alchemists and their search for gold by the stone of the philosophers to the creation of the world's first synthetic dye - Purple - and onto the invention of the transistor. This quest may seem abstract and highly theoretical. Yet it has delivered the greatest impact on humanity. By trying to answer this question, scientists have created theories from elements to atoms, and the strange concepts of quantum physics that underpin our modern, technological world.

We move around in space, but we are stuck in a prison of time moving ever forwards. Einstein said, 'The distinction between past, present and future is only a stubbornly persistent illusion.' Is our experience of the ticking clock merely a trick of the mind? Could science ever make the clock move backwards? Experiments in quantum physics are showing that the future influences the present: what happens later limits the choices we think we have now. The laws of physics say visiting or talking to ourselves in the past is possible – but changing history once we get there is not.

The key to understanding the universe seems to be understanding its smallest components. But the quantum realm bears little resemblance to the universe we know. Image a particle that can be many places at the same time and communicate changes instantly across vast distances, even to the other side of the Universe. Shrinking down billions of times, into the realm of atoms and sub-atomic particles, takes us into a bizarre world of paradoxes and multiverses. Explore with us quantum physics and the potential applications in computer science.

Go with us behind the scenes at CERN to follow one of the most epic and expensive scientific quests of all time: the search for the Higgs particle, believed to give mass to everything in our universe. However, the hunt for Higgs is part of a much grander search for how the universe works. It promises to help answer questions like why we exist and is a vital part of a Grand Unified Theory of nature". At the heart of the pursuit of the elusive particle is the same feature that makes snowflakes beautiful and human faces attractive: the simple and enchanting idea of symmetry. Presenter Jim Al-Khalil

Our world, our solar system, our universe, none of it would exist without a ghostly particle called the neutrino. They are our early warning system whenever there's trouble in the universe. Neutrinos trigger star-killing explosions, supernovas. Neutrinos can answer so many questions, from why do we exist to how was the universe created. Neutrinos can be the very reason that we exist at all. The more we understand these elusive particles, the more we can gain insight into how the universe works.