SSS 2009-07-17(在线收听

transcript

This is Scientific Ameican’s 60-Second Science. I’m Karen Hopkin. Got a minute?

 Horse racing is a sport that's 200 years old. And a day at the track is much more exciting now than it was back then. That's because horses are faster than they used to be. Or are they? A study in the July 17th issue of Science shows that it's the way that jockeys ride that's made racing more heart-pounding than before. Images from the late 1800s show that the boys in silks looked pretty relaxed as they went along for the ride. But modern jockeys-crouching, tightly coiled atop their galloping steeds-actively work to make sure their weight doesn't slow things down. Using GPS to track the riders' motions, scientists found that jockeys move out of phase with their mounts. That means that the horse doesn't have to physically move the jockey through each cyclical stride. As a result, races are five to seven percent faster than they were 100 years ago.

 Thanks for the minute, for Scientific Ameican’s 60-Second Science. I’m Karen Hopkin.
 

  原文地址:http://www.tingroom.com/lesson/sasss/2009/7/99105.html