时间:2018-12-18 作者:英语课 分类:2018年NPR美国国家公共电台2月


英语课

Why Don’t Marks On The Surface Of The Moon Disappear?月球表面的记号为何不会消失?



In 1969 when Neil Armstrong said “That’s one small step…”, he made a lasting 1 impression. On the moon, that is. Marks on the surface of the moon don’t disappear the way marks on the Earth do; a great example is the impact craters 2 we can see dotting the moon’s surface. Many of them are billions of years old!

1969年阿姆斯特朗的那句“人类一小步。”给人留下了难以磨灭的印象。月球表面的记号不会像地球那样轻易地消失。最典型的例子就是我们肉眼可见的月球表面散布的陨石坑。这些陨石坑中很多有数十亿年的历史。



But Why?

但为什么呢?



If you write your name in the sand at the beach, one day later there’s no sign you were there. What’s the difference?

如果你用沙子在沙滩上写下你的名字的话,一天过后,名字就会消失。差别在哪呢?



Here’s an experiment you can do to find out. Take two pans and fill them with soil and sand mixed together. Now have some young person press her or his hand down into the mixture to make an imprint 3. One of these surfaces will represent the Earth, and one the moon.

你可以做个实验来找出这种差别。拿出两个平底锅,里面放满土和沙子并将土和沙子掺在一起。然后找几个年轻人把手放在沙土中摁出手印。其中一个平底锅代表地球,另一个代表月球。



Try This!

试试看!



Leave your Earth pan outside. Take the moon pan inside and place a cardboard box over the top of it, weighted down with something heavy. Wait a couple days and check again. The moon pan will look the same. More than likely, though, the Earth pan won’t. Maybe the wind blew the sand around. Maybe it rained or snowed.

把代表地球的平底锅放在户外,然后把代表月球的平底锅放在室内并在它的上面放上一个硬纸盒,再压上一些重物。几天过后再进行观察,你会发现代表月球的平底锅没有任何变化。但代表地球的平底锅却并非如此,也许是风把沙子吹得到处都是,也许是被雨雪冲刷过。



The point is that Earth has an atmosphere, which results in wind, rain, rivers and streams, lots of motion. Of course, Earth is also volcanically 4 active: the ground shakes, lava 5 pours out, continents rise and fall. By comparison, nothing much ever happens on the moon–except for the impacts that give rise to those craters–even across billions of years. So an impression on the moon can be a lasting impression indeed!

答案就在于地球有一层大气,大气可以产生风、雨、河流、小溪等引起运动的事物。当然,地球的火山运动是非常活跃的,会造成地震、岩浆喷发、大陆沉降。相比之下,月球在数十亿年里基本不会产生这些现象(形成火山坑的撞击除外)。因此,你在月球上留下的印记会一直留在那哦!



1 lasting
adj.永久的,永恒的;vbl.持续,维持
  • The lasting war debased the value of the dollar.持久的战争使美元贬值。
  • We hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。
2 craters
n.火山口( crater的名词复数 );弹坑等
  • Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
  • The battlefield was full of craters made by exploding shells. 战场上布满弹坑。 来自《现代英汉综合大词典》
3 imprint
n.印痕,痕迹;深刻的印象;vt.压印,牢记
  • That dictionary is published under the Longman imprint.那本词典以朗曼公司的名义出版。
  • Her speech left its imprint on me.她的演讲给我留下了深刻印象。
4 volcanically
adv.火山似地,猛烈地
5 lava
n.熔岩,火山岩
  • The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
  • His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。
学英语单词
4-Hydroxyacetophenone
accurate traverse survey
angelica sylvestris l.
anti-suns
at the top of one's speed
batten sheet piling
bending load effect
biddable
bioherm limestone
blacksmith's daughter
blade height
candescent
chloroformyl chloride
cholesteryl compound
cladonia chlorophaea
claim for tax refund
concize
cone of support
contingency forecast
coral branch culture of eucheuma
cyclodopa
dawn raids
deictics
delay conditioning
dental appointment
doomage
doosje
dynamic tracking
eccentric gear
Einstein-Bohr equation
electro-magnetic radiation
entodontopsis nitens
erythrotaenia
excrementum bombycis meal
filter reactor
find A to do
for the rest
get a black eye
glycogen deposition
good money
Grey, Lady Jane
heading gyroscope
homegroups
homopoly acid
impurifications
infant-mortality
lateral spinal sclerosis
limit strength
liquid deuterium
long term experiment
low-interests
lubricating oil pump driven gear
Macclesfield reed count
matzoh meals
maximum permissible temperature rise
meliola araliicola
microtrabecular lattice
mill weir
mind-games
module object
non-selfs
numerical computation
orderto
pan breeze
pempheridaes
plain bumper
pleurolith
polar reciprocal
power-operated shearing machine
prestretching force
prokryotic
pulse sampling oscilloscope
pyruate kinase
rank of a node
refrigeration oil
removal panel
resume
robinov
rynds
safety valve testing
Scarlem
scarus forsteni
should'a
snatchingly
subpolynomial
suckup
sulfonated coal
Sulfurine
summer bird
take off lever
tenderization
the printed word
tightly-coupled system
vector coupling coefficient
ventilation by forced draft
ventral celiotomy
werebear
white slime
width angle
zephyr lilies
zone-box circuit