What makes plants grow is a simple enough question, but the answer turns out to be one of the most complicated and fascinating stories in science and took over 300 years to unravel. Timothy Walker, director of the Oxford University Botanic Garden, reveals how the breakthroughs of Swedish botanist Carl Linnaeus, Chelsea gardener Phillip Miller and English naturalist John Ray created the science of botany. Between them these quirky, temperamental characters unlocked the mysteries of the plant kingdom and they began to glimpse a world where bigger, better and stronger plants could be created. Nurseryman Thomas Fairchild created the world's first artificial hybrid flower - an entirely new plant that didn't exist in nature. Today, botanists continue the search for new flowers, better crops and improved medicines to treat life-threatening diseases.
In this episode Brian uncovers how the stunning diversity of shapes in the natural world are shadows of the rules that govern the universe. In Spain he shows how an attempt by hundreds of people to build the highest human tower reveals the force that shapes our planet. In Nepal, honey hunters seek out giant beehives that cling to cliff walls. The perfect hexagonal honeycombs made by the bees to store their honey conceal a mathematical rule. Off the coast of Canada, Brian explains how some of the most irregular, dangerous shapes in nature - massive icebergs that surge down from Greenland and into shipping lanes of the Atlantic - emerge from a powerful yet infinitely small force of nature. Even the most delicate six-sided snowflake tells a story of the forces of nature that forged it.