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A Stationary Satellite, part 1地球同步卫星(一) Some of the best devices in science have been anticipated by science fiction writers years before they existed.一些最先进的科学设备在被发明前就在科幻小说中被预料到了。Occasionally a writer comes up with an idea that can be put into practice within their lifetime!偶然的机会下,作家脑海中涌现出一个设想,就很可能会在他们有生之年内被实施。Such is the case with the geostationary satellite, first imagined by Arthur C. Clarke.地球同步卫星就属于这种情况。它是由Arthur C. Clarke首次构想出的。Clarke, famous for writing “2001: A Space Odyssey,” also wrote a scientific article titled ;Extra-Terrestrial Relays; in 1945.以作品《2001:A Space Odyssey》而著称的Clarke,在1945年写下了一部科学论文《Extra-Terrestrial Relays》。In it, he proposed a satellite that would remain motionless in the air, rather than passing by overhead.在这部论文里,他提出了一款卫星模型:可以在太空中保持静止不动而不是一味从高空在运行。Such a ;fixed; satellite would be useful for relaying television and radio signals, helping ships navigate, and a host of other things.而这样一款同步卫星将会被应用于传送电视和无线电讯号、护送船只航行以及一系列其他事务中。But how to do it? After all, heavy machinery cant just float.但是要怎样做到呢?毕竟,笨重的机械并不能漂浮在太空中。Most satellites handle this problem by being blasted into orbit around the planet.我们通过将大多数卫星送至行星运行的轨道,从而解决了这一问题。But in order to be in orbit, you have to be constantly moving. Can you think of a way around this?但是,卫星不得不时时刻刻地运行着。你能想出一个解决方法吗?How about putting a satellite into orbit both in the same direction as the planet rotates and at the same speed!在卫星进入行星运行轨道时,使其保持与行星运行同样的方向与速度。The result is a satellite that is, in fact, orbiting the planet.结果显示卫星实际上是环绕着行星轨道运行的,But the ground underneath it turns at the same rate as the satellite orbits, so the satellite is always above the same spot of ground.但是卫星底下的领域却保持着与卫星轨道同样的速度。因此这个卫星会一直固定在地面上空某点处。From our perspective on the earth, a geostationary satellite seems fixed in one spot.从地面上看,地球同步卫星似乎与地面保持相对静止了。 /201207/192247。

Science and Technolgy科技Citizen astronomy全民天文学A new world in your bedroom卧室里的新天地Amateur astronomers join the ranks of the planet hunters业余天文学家加入;猎星人;行列IN AN age of professionals, the ability of amateur scientists to make meaningful contributions has almost vanished.当今世界,专业人士主导天下,业余科学家想要做出积极贡献却心有余而力不足。Almost, but not quite.不足,绝非完全丧失。The internet allows professionals to make their data available for analysis by anyone, and some are happy to take advantage of the free labour this promises.在互联网的帮助下,专业人士们可以向任何人提供数据用于研究,其中不乏欢迎这种通过分享数据而获得免费劳力办法的人。This approach has proved particularly fruitful in astronomy, a science with a long history of amateur contributions.这种方法被实在天文学领域内极富成效。业余爱好者对天文学的贡献有着漫长的历史。Armchair astronomers have aly helped classify galaxies seen by Hubble, the main orbiting telescope of Americas space agency, NASA.已有没有严谨研究经验的天文学爱好者帮助将哈勃望远镜观察到的星系分类。哈勃望远镜是美国宇航局(NASA)主要的轨道望远镜。They have also looked for interesting asteroids, and kept an eye out for solar storms.业余天文学家们也已参与寻找有趣的小行星和观测太阳风暴。The latest project to involve them, called Planet Hunters, allows amateurs to search for extrasolar planets-those that orbit stars other than the sun.最新的;猎星人;计划号召业余爱好者们参与搜寻太阳系外行星——绕除太阳外的其他恒星运行的行星。It was set up by a group at the universities of Oxford and Yale, and links 40,000 participants with data gathered by Kepler, another NASA space telescope that is specifically designed to hunt for planets.此项目由哈佛大学和耶鲁大学的一个团体发起,向40000名参与者提供开普勒望远镜获取的数据。开普勒望远镜是NASA的另外一架太空望远镜,专门用于寻找行星。On September 26th the group announced, in a paper posted to arXiv, an online database, that its participants had discovered two probable exoplanets, one a Jupiter-like gas giant, and the other, possibly, a smaller, rocky world about twice the diameter of Earth.该组织于9月26日在一篇发表在 arXiv(一个在线数据库)上的论文里宣布,其成员发现了两颗极有可能的外部行星,一颗是与木星类似的气体巨行星,另外一颗可能是体积较小、直径约为地球两倍的岩石星体。Kepler works by monitoring the thousands of stars in its field of view for tiny changes in brightness.开普勒望远镜的工作原理是监测其视野内成千上万个恒星的亮度的微小变化。Mostly, these are natural fluctuations, but particularly sharp and regular changes might signify a planet passing in front of a star.大部分情况下,这些变化都是自然波动,但是一旦有急剧变化或者规律性变动,可能是行星在恒星前经过的标志。The raw data are sent to computers on Earth, converted into graphical form and made available to the Planet Hunters.原始数据将被传输到地球的计算机上,转化成图表,向猎星人开发。After logging onto the projects website, its users are given a brightness graph from a random star and asked to mark anything of interest.猎星人在登录该项目网站后将随机获得一张亮度图表,可根据兴趣进行任何标注。If several people flag the same star, the result is checked against the computer-derived results produced by the main Kepler team.如果多人标注了同一颗恒星,将与专门处理开普勒观测数据的计算机结果比对。Promising candidates are then checked again by ground-based telescopes.有可能存在的候选行星将由地面望远镜进一步确认。That allows Planet Hunters participants both to act as a benchmark for the star-detection algorithms and to discover planets the computers have missed, says Chris Lintott, an astronomer at Oxford who helps to run the project.来自剑桥大学的天文学家Chris Lintott说,这样,猎星人不仅能为恒星探测算法提供检验标准,还能发现计算机漏掉的行星。What people lack in speed (the computers have aly notched up over 1,200 candidate planets since Kepler was launched) they make up for in judgment.Chris Lintott帮助该项目的运行。人们在速度上的劣势在判断力上得到弥补(自开普勒望远镜启动以来,计算机已经发现超过1200颗候选行星)。Some stars being watched have very variable brightness. That is confusing for computers, but for human eyes is less of a problem.一些观测中的恒星亮度变化较大,这对于计算机来说难以把握,但是对于人眼却不成问题。And input from the human planet hunters is used to refine the algorithms, improving their performance.而且,猎星人输入的数据可以用来校正计算机算法,从而优化计算机性能。Planet Hunters grew out of Galaxy Zoo, which was set up in 2007 to help researchers classify galaxies spotted by Hubble-just the sort of fuzzy task that machines struggle with but humans excel at.猎星人计划的灵感来源于星系动物园计划。星系动物园计划成立于2007年,旨在帮助科研人员将哈勃望远镜观测到的星系分类——正是那种机器无法胜任而对于人类轻而易举的麻烦活。Galaxy Zoo spawned the Zooniverse, a collection of science projects that harness the power of amateurs.星系动物园计划孵化了动物宇宙计划——一批借助业余爱好者力量的科学计划。Although astronomical projects still dominate, other sciences are starting to adopt the idea.尽管主要应用于天文学计划,其他学科也开始采用这一想法。One Zooniverse project aims to reconstruct weather records from old Navy logs; another is helping to transcribe a cache of Egyptian papyri dating from the 1st century AD.动物宇宙的一个项目计划重现古老航海日志里的气象记录,另外一个项目计划抄录可追溯到公元1世纪的埃及纸莎草卷。Dr Lintott and his colleagues have asked researchers in other fields to submit more ideas, and hope to announce the shortlist in a few weeks time.Lintott士和他的同事们已经呼吁其他领域的科研人员们提供更多的想法,有望于几星期后公布最终入选名单。 /201210/205821。