The 'Castellers' from Villafranca band together to build one epic human tower from a circle, choosing symmetry to help build the tallest human tower they can muster. Can they defy gravity and become champions?

Best of Earth Science: http://bit.ly/EarthLabOriginals
Best of BBC Earth: http://bit.ly/TheBestOfBBCEarthVideos

Forces of Nature
Professor Brian Cox combines some of the most spectacular sights on Earth with our deepest understanding of the universe to reveal how the planet's beauty is created by just a handful of forces. In a perfect combination of accessible science and cutting-edge filming techniques, he explores the simplest possible questions about the planet we live on – such as why is water blue? How can a shape defy gravity? Why do bees make hexagonal honeycombs? – in order to reveal deeper truths about the cosmos and the forces of nature that govern everything in it.

This is a channel from BBC Studios who help fund new BBC programmes. Service information and feedback: http://bbcworldwide.com/vod-feedback-...