Shape

S1 E1: We can't directly see the forces that govern Earth, but we can see their shadows in the shapes of nature that surround us. If we understand why these shapes exist, we can understand the rules that bind the entire universe. Gravity is the great sculptor of our planet. Every two years, in Tarragona, Spain, towns from across the region compete to build the highest, most complex human towers. The shapes formed by hundreds of people in each team as they create towers up to 10 people high are beautiful but also carefully designed to combat the power of Earth's gravity. Every year hundreds of icebergs, some of Earth's most spectacular natural sculptures, break away from the Greenland glacier and drift into the Atlantic, causing a hazard to shipping and oil platforms. Unlike any other fluid on Earth, water expands as it freezes. Deep within the iceberg, electromagnetism, the force of nature that bonds atoms and molecules together, causes the water molecules to join in a lattice of billions of hexagons. The balance between the forces of gravity and electromagnetism create Earth's epic landscapes but our planet is unique in the Solar System - and perhaps the entire Universe because it has one thing that creates an even richer diversity of shapes: life. High in the Himalayas of Nepal, the Gurung people of Annapurna head out from their villages to harvest honey from the largest honeybees in the world. In the Florida Everglades we discover another of nature's shapes, this time forged by evolution. The Florida manatee is the most rotund of all manatees. As it lives furthest north, in cooler waters than its Caribbean cousins, it has developed a unique body shape. There is one rule of shape that is found across the animal kingdom - bilateral symmetry - a body with a left and a right and a head with sense organs. In South Korea we meet the Haenyo of Jeju Island, a proud group of women, many of them older ladies, who supplement their income by free-diving for food.