Absolute Genius presenters Dick and Dom sample all the fun of the fair in this thrill ride through the engineering genius of roller coasters and water slides. As well as learning how coasters somehow stay on the track when upside down, the boys don their swim shorts and bravely research the science behind the world's fastest water slides. Then they put their theories to the test with an epic slide challenge which attempts to topple a record owned by a certain Usain Bolt. Show less