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
39
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] The word "envisions"(Para. 3)is closest in meaning to______.
选项
A、completes
B、prefers
C、conceives
D、views
答案
C
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3296178.html
相关试题推荐
Theprotestersopposebuildingahigh-riseintheirneighborhood,statingthati
Everystreetinthatneighborhoodhasadifferent______ofbuildingboastingaco
Manyfarmershavetakenadvantageofrainwhenitisgoingtocome,bymakingha
"You’llsortitout,"heassuredhercallouslyastheyenteredthebuilding,and
Healthsystemsstrengthening—which,inglobalhealthspeak,meansbuildingand
Itwouldbewrongto______someoneforerroneousremarksbecauseitisimpossible
Asweknow,beforescientistscomeupwithaneffectivetreatment,cancerissti
Constructionofthegiganticofficebuildinginthiscitywasforyearsintermit
Constructionofthegiganticofficebuildinginthiscitywasforyearsintermit
Scientistsaremakinghugestridesinbattlingoneofthetopthreekillerdisea
随机试题
Oftenconjuringimagesofdank,smelly,mosquito-infestedwastelands,uponcl
ThePressConferenceI.AdvantagesofthePressConfere
UrbanEnergyPlanningforaSustainableEnvironmentThePe
IntheUnitedStates,campaigns【S1】______everyelectionandoftenbeginmany
完全电流差动母线保护不适用于()场合。A.单母线 B.双母线 C.双母
A.48m,36m B.38.6m,24.2m C.25.2m,26m D
下列叙述不正确的是A.多数晚期流产为稽留流产 B.先兆流产如症状消失,有可能继
包合物中客分子药物不包括A.挥发性成分 B.难溶性药物 C.苦味药物 D.
消防控制柜自动状态、手动状态应有明显标志并可相互转换。
下列各项中属于钻石模型的要素的是()。A.生产要素 B.需求条件 C.相关
最新回复
(
0
)