The Structure of Earth

56:18

Just outside Paris, inside a hi-tech vault, and encased in three vacuum-sealed bell jars, rests a small metallic cylinder about the diameter of a golf ball. It may not look like much, but it is one of the most important objects on the planet. It affects nearly every aspect of our lives including the food we eat, the cars we drive, even the medicines we take. It is the kilogramme, the base unit of mass in the International System of Units. This small hunk of metal is the object against which all others are measured. Yet over time, its mass has mysteriously eroded by the weight of an eyelash. A change that, unbeknownst to most, unleashed a crisis with potentially dire consequences. Follows the ensuing high-stakes, two-year race to redefine the weight of the world, and tells the story of one of the most important objects on the planet.

2021 • Physics

58:15

There is a strange and mysterious world that surrounds us, a world largely hidden from our senses. The quest to explain the true nature of reality is one of the great scientific detective stories.

Horizon • 2011 • Physics

59:09

Scientists genuinely don't know what most of our universe is made of. The atoms we're made from only make up four per cent. The rest is dark matter and dark energy (for 'dark', read 'don't know'). The Large Hadron Collider at CERN has been upgraded. When it's switched on in March 2015, its collisions will have twice the energy they did before. The hope is that scientists will discover the identity of dark matter in the debris. The stakes are high - because if dark matter fails to show itself, it might mean that physics itself needs a rethink.

Horizon • Physics

59:02

Time travel is not forbidden by the laws of nature, but to build a time machine, we would need to understand more about those laws and how to subvert them than we do now. And every day, science does learn more. In this film Horizon meets the scientists working on the cutting edge of discovery - men and women who may discover how to build wormholes, manipulate entangled photons or build fully functioning time crystals. In short, these scientists may enable an engineer of the future to do what we have so far been only able to imagine - to build a machine that allows us travel back and forward in time at the touch of a button. It could be you! Science fiction?

Horizon • 2018 • Physics

56:41

Over a single weekend in 1869, a young Russian chemistry professor named Dmitri Mendeleev invents the Periodic Table, bringing order to the growing gaggle of elements. But this sense of order is shattered when a Polish graduate student named Marie Sklodowska Curie discovers radioactivity, revealing that elements can change identities — and that atoms must have undiscovered parts inside them.

Part 2 • The Mystery of Matter: Search for the Elements • 2015 • Physics

46:01

From the first gas turbine to tomorrow's hypersonic jet engines, see the evolution of the machine that is changing the world.

S1E4 • Survival in the Skies • 2019 • Physics