Scientists at London's Natural History Museum explain how they believe a shark can smell "a drop of blood in an ocean of water", through their newly-discovered knowledge, based around how water flows through a shark's nasal chamber. Beau Lotto, a British neuroscientist, explains how our brains are tricked, by past experiences, to perceive ambiguous objects or images differently to their actual/normal state, and the head of Sports Engineering from Sheffield's Hallam University - Steve Haake - explains how altitude will affect the players at the 2010 World Cup Finals in South Africa.