Difficulties in Astronomy托福听力原文翻译及问题答案

Difficulties in Astronomy托福听力原文翻译及问题答案

一、Difficulties in Astronomy托福听力原文：

Narrator:Listen to part of a lecture in an astronomy class.

Male Professor:So,how many of you have seen the-the MilkyWay,the MilkyWay galaxy,in the sky?You?You have?Male Student:Yeah,I was camping.And there was uh,no moon that night.It was super dark.Male Professor:Uh,anybody else?Huh,not too many…Isn’t that strange that the MilkyWay is the galaxy that the planet Earth is in and most of us have never seen it?Now what’s the problem here?Female Student:Light pollution,right?From streetlights and stuff.

Male Professor:Yes.Especially unshielded streetlights,you know,ones that aren’t pointed downward…Now,here’s an irony:the building we’re in now,the astronomy building,not far from our observatory,has unshielded lights.

Male Student:So,the problem’s pretty widespread…Male Professor:It’s basically beyond control,as far as expecting to view the night sky anywhere near a city…I mean,uh,I’ve lived around here my whole life,and I’ve never seen the Milky Way within the city limits—and I probably never will…there’s a price for progress,huh?But let’s think beyond light pollution.That’s only one kind of,uh,technological advance that has interfered with astronomical research.

Can anyone think of another?No?OK,let’s look at it this way…we don’t only get information by looking at the stars…for the past 70 years or so,we’ve also used radio astronomy,which lets us study radio waves from the sky…Male Student:How can you observe radio waves?I mean,tell anything about the stars from that?Male Professor:Well,in optical astronomy—using a telescope and observing the stars that way—we rely on visible light waves…What we’re seeing from Earth is actually electromagnetic radiation that’s coming from stars—and just one part of it is visible light.But there are problems with that.

When photons in light waves hit objects in our atmosphere—water droplets,oxygen and nitrogen molecules,dust particles,and so on—these objects are illuminated,they’re lit up.And those things are also being lit by all our streetlights,by the moon,all this ambient light.And on top of that,when that visible radiation bounces off those molecules—it scatters in all directions.And,well,light from stars,even nearby in our own galaxy,doesn’t stand a chance against that…Basically the light bouncing off all these objects close to Earth is brighter than what’s coming from the stars.

Now,radio waves are electromagnetic radiation that we can’t see.Nearly all astronomical objects in space emit radio waves—whether nearby stars or objects in faraway galaxies—they all give off radio waves.And,unlike visible light waves,these radio waves can get through the various gases and dust in space,and through our own earth’s atmosphere comparatively easily.Male Student:OK,then we might as well give up on optical astronomy and go with radio astronomy…Male Professor:Well,the thing is,with radio astronomy you can’t just set up a telescope in your backyard and observe stars.One problem is that radio waves from these faraway objects,even though they can get through,are extremely faint.So we need to use radio telescopes specially designed to receive these waves,and then…well,we can use computers to create pictures based on the information we receive.Male Student:That sounds cool.So how do they do that?

Male Professor:Well,it’s kind of like the same way a satellite dish receives its signal,if you’re familiar with that.But radio telescopes are sometimes grouped together—it’s the same effect as having one really big telescope—to increase radio wave gathering power.And they use electronics,quite sophisticated…

Yeah,it’s neat how they do it,but-but for now why don’t we just stick with what we can learn from it?Uh,some very important discoveries have been made by this technology,especially if you consider that some objects in space give off radio waves,but don’t emit any light.We’d have trouble discovering those sorts of bodies,much less studying them,using just optical telescopes.

Female Student:Well,if the radio waves are so good at getting through the universe,what’s the problem?Male Professor:Well,answer this:how come people have to turn off their cell phones and electronic devices when an airplane is about to take off?Male Student:The phones interfere with the radio communication at the airport,right?Female Student:Oh,so our radio waves here,on Earth,interfere with the waves from space?Male Professor:Yes,signals from radios,cell phones,TV stations,remote controls—you name it.All these things cause interference.We don’t think about that as often as we think about light pollution.But all those electrical gadgets pollute the skies,just in a different way.

二、Difficulties in Astronomy托福听力中文翻译：

旁白：在天文学课上听一节课的一部分。

男教授：那么，你们中有多少人见过天空中的牛奶路，牛奶路星系？你你有吗？男学生：是的，我在露营。那天晚上没有月亮。天非常黑。男教授：呃，还有其他人吗？嗯，不太多……牛奶路是地球所在的星系，而我们大多数人从未见过它，这不是很奇怪吗？现在这里有什么问题？女学生：光污染，对吗？街灯之类的东西。

男教授：是的。尤其是非屏蔽路灯，你知道，那些不是朝下的……现在，这里有一个讽刺：我们现在所在的大楼，天文大楼，离我们的天文台不远，有非屏蔽灯。

男学生：所以，这个问题相当普遍……男教授：这基本上是无法控制的，就期望在城市附近的任何地方看到夜空而言……我的意思是，呃，我一生都住在这里，我从来没有在城市范围内看到过银河，我可能永远也不会看到……进步是有代价的，对吧？但让我们超越光污染来思考。这只是干扰天文学研究的一种技术进步。

有谁能想到另一个吗？不好吧，让我们这样看……我们不仅通过观察恒星来获取信息……在过去70年左右的时间里，我们还使用射电天文学，它让我们研究来自天空的无线电波……男生：你怎么能观察无线电波？我是说，从那件事上说说星星的事？男教授：嗯，在光学天文学中，我们使用望远镜，通过可见光波观察恒星……我们从地球上看到的实际上是来自恒星的电磁辐射，其中只有一部分是可见光。但这也有问题。

当光波中的光子击中大气层中的物体时，水滴、氧和氮分子、尘埃粒子等这些物体被照亮，它们被点亮。这些东西也被我们所有的路灯，月亮，所有这些环境光照亮了。最重要的是，当可见辐射从这些分子上反弹时，它会向各个方向散射。而且，好吧，来自恒星的光，即使在我们银河系附近，也没有机会反对……基本上，从所有这些靠近地球的物体上反弹的光比来自恒星的光更亮。

无线电波是我们看不见的电磁辐射。几乎所有太空中的天体都会发射无线电波，无论是附近的恒星还是遥远星系中的天体，它们都会发射无线电波。而且，与可见光波不同，这些无线电波可以通过太空中的各种气体和尘埃，并相对容易地通过我们自己的地球大气层。男学生：好吧，那么我们还是放弃光学天文学，转而学习射电天文学吧……男教授：好吧，问题是，射电天文学不能只在后院安装望远镜，观察恒星。一个问题是，来自这些遥远物体的无线电波，即使可以穿透，也极其微弱。因此，我们需要使用专门设计的射电望远镜来接收这些波，然后……嗯，我们可以使用计算机根据我们接收到的信息来创建图片。男学生：听起来很酷。那么他们是怎么做到的呢？

男教授：如果你熟悉的话，这有点像卫星天线接收信号的方式。但射电望远镜有时会组合在一起，这与使用一个真正的大望远镜来提高无线电波收集能力的效果是一样的。他们使用电子设备，非常复杂…

是的，他们的做法很好，但现在我们为什么不坚持从中学到什么呢？呃，这项技术已经取得了一些非常重要的发现，特别是如果你考虑到太空中的一些物体会发出无线电波，但不会发出任何光。如果仅仅使用光学望远镜，我们很难发现这些天体，更不用说研究它们了。

女学生：好吧，如果无线电波很擅长穿越宇宙，那有什么问题？男教授：那么，回答这个问题：当飞机即将起飞时，人们为什么要关掉手机和电子设备？男生：电话干扰了机场的无线电通信，对吗？女生：哦，那么我们地球上的无线电波干扰了来自太空的电波？男教授：是的，从收音机、手机、电视台、遥控器发出的信号你都能说出。所有这些都会造成干扰。我们不会像考虑光污染那样经常考虑这个问题。但所有这些电子设备都以不同的方式污染了天空。

三、Difficulties in Astronomy托福听力问题：

Q1:1.What is the lecture mainly about?

A.Recent advances in technology used by astronomers

B.How radio astronomy has led to advances in communication technology

C.Important discoveries made by radio astronomers

D.Difficulties astronomers have in observing the universe

Q2:2.What is the professor's attitude about light pollution in cities?

A.He feels that it should be carefully regulated.

B.He believes it is unfortunate.

C.He thinks astronomers have not done enough to address the issue.

D.He believes that the severity of the problem is often exaggerated.

Q3:3.According to the professor,why are radio waves particularly useful for astronomical observations?[Click on 2 answers.]

A.Some astronomical bodies emit radio waves but not visible light.

B.Radio waves provide more information about star composition than visible light waves do.

C.Radio waves can be detected with simple equipment.

D.Radio waves can pass through particles in space.

Q4:4.What does the professor imply is an advantage of optical astronomy over radio astronomy?

A.It allows for more precise observations.

B.It is better for making observations within our own galaxy.

C.It requires less sophisticated equipment.

D.It is not affected by the weather.

Q5:5.According to the professor,why do radio astronomers sometimes have difficulty studying very distant objects?[Click on 2 answers.]

A.Signals from closer objects interfere with radio waves from space.

B.Particles in the atmosphere change the direction of radio waves.

C.Radio waves from space are not very strong.

D.Light waves from sources on Earth alter radio waves from distant objects.

Q6:6.What does the professor mean when he says this:

A.He wants to emphasize the progress that has been made in radio astronomy.

B.He thinks radio astronomy and optical astronomy both provide valuable information.

C.He does not want to spend time discussing the technology of radio telescopes.

D.He would like the students to give examples of discoveries made with radio telescopes.

四、Difficulties in Astronomy托福听力答案：

A1:正确答案：D

A2:正确答案：B

A3:正确答案：AD

A4:正确答案：C

A5:正确答案：AC

A6:正确答案：C