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
actual payload
aggreged
amino acid decarboxylases
Ankylostomum
Atlantic, the
Ban Kammasen
bean sprout growing machine
bias sampling technique
Bonjean curve
brevissimicolpate
catch drain
cell remnant
coaming hatch
colloidal phosphate
complement pulse
consent search
Cystoporata
de-differentiations
Dieulefit
duplex signalling
Dīdīmtu
echinostelium arboreum
entered on
European elk
eyeletter
fibre system
Finn R.
framilies
French Communist Party
gender consistency
goolie
granosolarium gemmiferum
heavy clay industry
hemiscotosis
IALP
impact crushing
imperfect albumen
integral inequality
intercommuning
ivoriness
K-hole
lamaze method of childbirths
lawn-boy
lightweight aggregate block
Magnetic storage device
messaging server
mobile store
model wrap(age)
modfet circuit
natural adhesive
needle-mackerel
new construction survey
open porosity
parallel track
Paranhos
pebble-stone
Pedicularis paiana
personal digital assistants
phase-under-voltage relay
playthrough
pocketlike
polarizing pyrometer
preemption capability
propionyl
psychrometric chart
pteromata
red cell iron utilization
reendothelizing
refinery process
rose-cheeked
sealed-bid common value auctions
semiwinterness
shiteaters
siphonostomatoid
snooper scope
specification check
spring (loaded)lubricator
springwoods
star wheel dosing pump
statement of mercantile funds and application
step-by-step dialling
sterna hirundoes
stuffer-box textured yarn
Tabeal
Thymine-2-deoxyriboside
took pains
torch blower
totarol
toxophiliac
travler's checks
turble
varistor(-er)
vector algebras
warm air mass
west country whipping
whenyou
Wiggensbach
work of expansion
xylonamide
yfere
yoko-shiho-gatame
Zaqatala