首页
登录
职称英语
Scientists have taken a giant leap toward making possible the dream of buildi
Scientists have taken a giant leap toward making possible the dream of buildi
游客
2023-12-22
49
管理
问题
Scientists have taken a giant leap toward making possible the dream of building a powerful telescope on the moon that could withstand even the harshest of lunar conditions.
Writing in Thursday’s edition of the journal Nature, they said they coated a special type of liquid surface with a layer of silver to make a highly reflective mirror like one that could be used in any future, moon-based telescope.
"It’s the breakthrough that we need," lead researcher Ermanno Borra of Universite Laval in Quebec, Canada, said in a telephone interview. "If you want to have a liquid mirror telescope on the moon, you need the right liquid. If you don’t have the right liquid, forget it. It’s as simple as that." Borra envisions a telescope with a liquid mirror measuring 66 feet to 328 feet wide.
Such a telescope, which has drawn NASA’s interest, could provide astronomers on Earth unprecedented views into distant reaches of the universe, studying objects far more faint even than NASA’s planned James Webb Space Telescope, due for a 2013 launch. Astronomers hope such an instrument could allow them to study the early phases of the universe after the Big Bang.
Advocates say a large telescope on the moon would be more cheaply and easily built using a liquid mirror rather than a conventional glass one. The researchers think any liquid-mirror telescope on the moon would not come before 2020 at the earliest.
The scientists made use of a liquid made of "ionic salts" that remains fluid at super-low temperatures. They deposited a thin layer of chromium particles on the liquid, then added a layer of silver particles to complete the mirror.
Liquid mirror telescopes differ from conventional ones in that their primary mirrors, which gather and focus light, are made of reflective liquid instead of polished glass. The liquid can be poured into a spinning container, spreading out to make a thin, smooth, parabolic shape that can be used as a telescope mirror, the researchers said.
The silver layer that is created is completely smooth, highly reflective, can stay stable for months, and the ionic liquid that it covers does not evaporate, the researchers said. [br] What is the main idea expressed in the passage?
选项
A、Ermanno Borra of Universite Laval as a leading role in the research.
B、The feats of Astronomers by using the liquid mirror telescope.
C、The silver layer used in the liquid mirror telescope.
D、The dream of building a liquid mirror telescope on the moon.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3296181.html
相关试题推荐
Constructionofthegiganticofficebuildinginthiscitywasforyearsintermit
Scientistsaremakinghugestridesinbattlingoneofthetopthreekillerdisea
Ourgratefulthanksare________tothepolicedepartment’shelpinthemakingof
Iwouldhavefinishedmypaperifitwasatallpossible,butIwasfullyoccupi
Toweakenthedamageforearthquakes,scientistsareworkingonwaystoenablea
Mostscientistsbelieveitislegitimatetouseanimalsinmedicalresearch.A、de
Manyfarmershavetakenadvantageofrainwhenitisgoingtocome,bymakingha
"You’llsortitout,"heassuredhercallouslyastheyenteredthebuilding,and
Healthsystemsstrengthening—which,inglobalhealthspeak,meansbuildingandr
[originaltext]Italianscientistshaveraisednewhealthconcernsaboutthesafe
随机试题
Anoperation,*,isdefinedasfollows:foranypositivenumbersaandb.[img]2
Whichofthefollowingistrueaccordingtothespeaker?[br][originaltext]Joe
使用光纤进行通信容易受到外界电磁干扰,安全性不高。
关于协方差与相关系数,以下说法错误的是()。A.协方差的正负反映了两个资产收益
患者女,55岁。6月前出现不明原因的下腹坠胀,l月前出现阴道不明原因出血,妇科检
维生素D的佝偻病预防剂量为每日A:200~300U B:300~400U C
以下哪些投资者是国债市场的主要参与者?()A.商业银行 B.广义基金
评价幼儿园的儿童智力水平或诊断智力低下的重要方法是( )。A.斯坦福-比奈量表
投资决策中,决策机构委托咨询单位对投资项目进行独立的调查、分析、研究和评价,建立
根据《环境影响评价技术导则生态影响》,关于生态环境现状调查要求的说法错误的是(
最新回复
(
0
)