[ti:New Skateboard Defies Gravity] [ar:Jonathan Evans] [al:Technology Report] [by:www.51voa.com] [00:00.00]From VOA Learning English, this is the Technology Report. [00:04.14]Can you imagine riding around the streets [00:08.27]of your hometown on a skateboard without wheels? [00:12.35]In the late 1980s, [00:14.81]film director Robert Zemeckis [00:17.47]showed a skateboard floating above the ground [00:20.73]in his movie Back To The Future Part II. [00:24.35]Now, an American company, Arx Pax, [00:28.98]has moved the idea for such a device [00:32.35]from a futuristic dream to reality. [00:35.89]The new product operates on the same rules [00:40.39]that govern magnetism. [00:42.37]When similarly charged ends of two magnets get close together, [00:47.43]they repel or push away from each other. [00:51.20]That force can make an object levitate or hover in space. [00:56.82]Since the 1980s, [00:59.52]levitation has been used on trains in Europe, Japan and China. [01:05.99]These maglev trains, [01:09.16]seem to float above the ground. [01:11.72]There is no contact between the bottom [01:15.09]of the cars and the surface of the train track. [01:18.73]Maglev trains are almost noiseless and can move very fast. [01:25.32]Greg Henderson says the same technology [01:28.87]can make anything hover, even buildings. [01:32.56]"Imagine there's an earthquake [01:35.31]and the early warning turns on the warning systems [01:38.33]and the supports fall away as the building starts to hover. [01:42.12]The shaking stops, the supports return, [01:44.42]and no one in that room or in that building [01:46.99]ever knew there was an earthquake." [01:48.06]Greg Henderson's company [01:50.19]created the first maglev hoverboard, called Hendo. [01:53.84]It can hold a single person [01:57.39]about 2.5 centimeters above a metal surface. [02:02.04]"We are creating a magnetic field, [02:04.66]and then through a method of induction, [02:07.32]that's part of our secret sauce, [02:09.12]we are creating a secondary [02:11.13]and equal magnetic field in this conductive surface." [02:15.95]Batteries provide the electricity needed [02:19.27]to power Hendo's four engines. [02:22.09]However, the batteries only last for a short time. [02:27.33]But design engineer Kyle O'Neil says [02:31.67]they last long enough for experienced skateboarders [02:35.94]to learn how to control the hoverboard. [02:39.31]"Some people say it's like snowboarding. [02:41.44]Some say it's how they imagined a hoverboard [02:44.81]is supposed to be, which is kind of an interesting response [02:47.49]because no one's ever ridden one before." [02:49.34]The creators of Hendo say they do not expect [02:53.98]to see their hoverboard on the streets anytime soon. [02:58.65]The reason: it only works on a metal-covered surface. [03:04.01]But they say larger hover engines [03:07.19]could be used to transport containers in storerooms. [03:11.65]For now, their dream is to build a recreation area [03:16.99]where anyone can take a ride on a hoverboard. [03:21.10]And that's the VOA Learning English Technology Report. [03:26.16]For more technology stories, go to our website 51voa.com. [03:34.89]Give us a like on the VOA Learning English Facebook page. [03:40.78]Follow us on Twitter at VOA Learning English. [03:47.40]You can also watch vedios on the VOA Learning English YouTube channel. [03:55.01]I'm Jonathan Evans. [03:57.25]¸ü¶àÌýÁ¦Çë·ÃÎÊ51voa.com