【英语时差8，16】外星人来电，说什么？

 the previous show Don and Yael discussed communication from other worlds. Well, as it turns out if E.T. does try to phone it will be much more complicated than "can you hear me now"?   D: Okay, Yael, so suppose one day scientists pick up a transmission they think is generated by aliens. Now what? Do we build a landing strip and break out the welcome wagon¹?

Y: Whoa, Don. Slow down. Here's the thing about picking up alien broadcasts. The receivers scientists are currently using to listen to space noise are designed to find constant signals, or signals that are pulsing at regular intervals². But any message carried by these signals would probably be lost because the receivers can't pick up the modulation³, or rapid variations, in the base signal. The SETI institute, which searches for extra terrestrial life, has compared picking up a signal's modulation to picking up the sound of a flute⁴ when it's masked by the noise of a waterfall.

D: Huh, so if we won't be able to tell what they're saying, what good is picking up the transmission in the first place?

Y: Well, for one thing, scientists would still have enough data to pinpoint⁵ where in the sky the transmission is coming from. And any slow changes in the broadcast frequency would reveal information about the rotation⁶ and movement of the aliens' planets.

D: Okay, but how will we know if they're friendly?

Y: Well, if we ever do detect a transmission, this would be huge news--D: No kidding--Y: And the government would definitely allocate⁷ funds to building larger instruments capable of picking up signal modulations. However, even once scientists are able to measure the modulation, it isn't certain that we'll be able to understand the message. I guess everyone's hoping that if the aliens are anything like us, they'll send simple pictures and easy-to-decode messages. 

1 wagon   

n.四轮马车，手推车，面包车；无盖运货列车

参考例句：

• We have to fork the hay into the wagon.我们得把干草用叉子挑进马车里去。
• The muddy road bemired the wagon.马车陷入了泥泞的道路。

2 intervals   

n.[军事]间隔( interval的名词复数 )；间隔时间；[数学]区间；（戏剧、电影或音乐会的）幕间休息

参考例句：

• The forecast said there would be sunny intervals and showers. 预报间晴，有阵雨。
• Meetings take place at fortnightly intervals. 每两周开一次会。

3 modulation   

n.调制

参考例句：

• The soft modulation of her voice soothed the infant. 她柔和的声调使婴儿安静了。
• Frequency modulation does not allow static to creep in. 频率调制不允许静电干扰混入。

4 flute   

n.长笛；v.吹笛

参考例句：

• He took out his flute, and blew at it.他拿出笛子吹了起来。
• There is an extensive repertoire of music written for the flute.有很多供长笛演奏的曲目。

5 pinpoint   

vt.准确地确定；用针标出…的精确位置

参考例句：

• It is difficult to pinpoint when water problems of the modern age began.很难准确地指出，现代用水的问题是什么时候出现的。
• I could pinpoint his precise location on a map.我能在地图上指明他的准确位置。

6 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

7 allocate   

vt.分配，分派；把…拨给；把…划归

参考例句：

• You must allocate the money carefully.你们必须谨慎地分配钱。
• They will allocate fund for housing.他们将拨出经费建房。