In the first of this year's Christmas lectures, Dr Mark Miodownik investigates why size matters in animal behaviour. He reveals how the science of materials - the stuff from which everything is made - can explain some of the most extraordinary and surprising feats in the animal kingdom. Dr Mark Miodownik zooms into the microscopic world beneath our fingertips. In this unfamiliar landscape, strange forces dominate the world and common sense goes out of the window. He reveals how this tiny hidden world can make objects behave like magic, and discovers the secrets of the extraordinary metals that make jet engines possible. In the last of this year's Christmas Lectures, Dr Mark Miodownik investigates the world of the very big and very tall. He reveals that, at this scale, everything is governed by a battle with one of the strangest forces in the universe - gravity.