Part of the show Origin of Earth, The Moon and Life
I'm sure it's something you've pondered long and hard after wasting a few quid down at the bookies - what actually makes for a fast racehorse? Apparently around 80% of modern racehorses are descended from only one stallion - an 18th century nag who went through every race unbeaten. Two centuries later, jockeys and punters alike are still puzzling over what made him so good, and what makes a fast horse. There is also a slightly more fundamental question to be answered - how do horses remain upright when each of their legs is actually in the air for 80% of the time when they gallop. To answer these problems, scientists at the Royal Veterinary College have been making computer simulations of horses. They built the models using data gathered from real horses running about, and discovered that horses legs are, in fact, built like pogo sticks. They store energy in their muscles and tendon, like the spring in the pogo stick, then release it with every step to propel themselves upwards and forwards. Horses with stiffer legs apparently have trouble releasing this energy, and are slower. Also the team found that faster horses bring their legs forward more quickly than slowcoaches, but this is more difficult for large and long-legged horses, so leggier doesn't always mean faster. The team also studied portraits of Eclipse, the 18th century equine superstar and found, rather disappointingly, that he was almost exactly average. Being not too tall and not too short seems to be the perfect recipe for speed. So maybe that's something to watch out for next time the Grand National comes around.