网站首页 手机版 网站地图 TAG标签

设为首页 加入收藏

当前位置: 主页 > 英语文章阅读 > 行业英语 >

寻找外星生物 The search for alien life

更新时间:2012-08-31    来源/发布:www.en369.cn    作者/编辑:英语作文网

Science and technology.

科技。

The search for alien life

寻找外星生物

Twinkle, twinkle, little planet

闪烁吧,小行星

An undervalued optical trick may help to find life in other solar systems

一个不被人重视的光学方法可能能帮助寻找其他太阳系的生命

MOST astronomical telescopes employ reflection to focus starlight. A concave mirror creates an image from this light using a design pioneered in the 17th century, by Sir Isaac Newton. Those telescopes that do not employ reflection use refraction. They have a system of lenses, an idea first used to look at the stars by Galileo.

大部分天文望远镜都是运用的焦点星光的反射原理。 早在17世纪,艾萨克.牛顿就开创性的利用这个光,让凹透镜产生了一个图像。 那些不利用反射的望远镜利用的是折射。 他们有透镜系统,利用透镜系统的想法最早是伽利略用来观测星星的。

But there is a third way to focus light. A century and a half after Newton, and more than two after Galileo, a Frenchman called Augustin-Jean Fresnel worked out that you can do it using diffraction. A set of concentric rings, alternately transparent and opaque, will scatter and spread light waves in a manner that causes them to reinforce each other some distance away, and thus form an image. The rings are known as a zone plate. And Fresnel's countryman, Laurent Koechlin, of the Midi-Pyrenees observatory, thinks zone plates are the way to find out if there is life on other planets.

但还存在第三种聚焦光源的方法。 在牛顿利用星光的150年后,伽利略的透镜系统的两百多年后,一个名叫奥古斯丁.让.菲涅尔的法国人想到也可以利用衍射来达到目的。 一组兼有透明和不透明的同轴环可以分散和传播光波,并且在稍远的地方可以再使他们重新聚焦,由此形成一个图像。 这些环被称作波带片。 法国南比利牛斯天文台劳伦.凯什兰认为波带片可以用来寻找其他星球上是否存在生命。

Seeing oxygen in another planet's atmosphere would be a giveaway of biological activity because the gas is so reactive that it needs to be continuously renewed. That would almost certainly mean something akin to photosynthesis was going on, for no known non-biological process can produce oxygen from common materials in sufficient quantity. Looking at such an atmosphere, though, is tricky. Stars are so much brighter than the planets which orbit them that their light overwhelms the small amount reflected from a planet's surface. And this is where Fresnel comes in.

在其他星球的大气层发现氧气则表明这个星球上有生物活动,因为氧气是一种非常活跃的气体,所以他需要不停的更新。 而这也就基本上意味着星球上进行着某些类似于光合作用的活动,因为在我们已知的非生物学过程中,没有一种过程可以在普通材料供应充足的情况下产生氧气。 然而,观测到这样的大气层也是非常难的。 恒星比以他们为轨道运行的行星亮得多,他们的光盖过了从行星表面上反射过来的少量光。 而这也就是菲涅尔的突破口。

Fresnel telescopes have not been developed in the past because the image formed by one that was large enough to rival a useful-sized reflecting telescope would be several kilometres from the zone plate. But Dr Koechlin does not worry about that, because his Fresnel telescope will be in space. Free of the confounding effects of the Earth's own atmosphere, it will be able to isolate images of alien planets, make spectra of the light from their air, and examine those spectra for the characteristic dark lines that are caused by part of the light being absorbed by particular gases-oxygen among them.

本文标签

alien

search

外星

for

Life

the

专题推荐

更多相关

本站简介- 站内公告- 原创投稿- 广告服务- 版权声明- 联系我们 - 手机访问
Copyright @ 2008-2018 英语作文网 online services. Security support by en369.cn