时间:2018-12-24 作者:英语课 分类:2018年科学美国人5月


英语课

Jupiter and Venus Squeeze Earth's Orbit


The Sun exerts an enormous and obvious influence on the Earth, with its gravity and light. But other bodies also have a small say in our affairs.


太阳用其重力和光线对地球产生巨大而明显的影响。但其他天体对地球也会产生轻微的影响。


"We're not alone in the solar system, there are other planets.” Dennis Kent, a geologist 1 at Rutgers University, and Columbia's Lamont-Doherty Earth Observatory 2. "And as we circle the sun, those other planets and also our moon exert effects on our orbit."


“罗德斯大学的地质学家Dennis Kent和哥伦比亚大学的Lamont-Doherty Earth Observatory表示:“我们并不孤单,太阳系中还有其他行星。当我们绕太阳转时,那些其他星球以及月球也在影响我们的轨道。”


In fact, planetary scientists have long hypothesized that Venus and Jupiter squeeze the Earth's orbit from circular to elliptical and back every 405 thousand years. During an elliptical orbit, when the distance from the sun varies more, the differences between the seasons would be more extreme than when the orbit is virtually circular. Problem is, it's been hard to verify that this oscillation between orbit shapes exists.


事实上,行星科学家很早就假设,金星和木星将地球的轨道,从圆形轨道挤压到椭圆形轨道,并且每40.5万年回归一次。在椭圆轨道中,当与太阳的距离变化更大时,季节之间的差异,将比轨道几乎是圆形时更为极端。那么问题是,很难验证这种轨道形状之间的振荡是否存在。


But Kent and his colleagues came up with a way—by boring down into the Earth. They took a rock core from the east coast, which has excellent sediment 3 records—good evidence of extreme seasonal 4 variations. They compared that core with another from Arizona, embedded 5 with zircons. The zircons contain trace amounts of uranium, which decays in a predictable way—meaning the Arizona core could thus be dated based on uranium content.


但Kent和他的同事,想出了一条通往地球的道路。他们从东海岸采集了一块岩芯,这块岩芯具有极好的沉积物记录——季节变化的良好证据。他们将这个岩芯与来自亚利桑那州的另一个岩芯,进行了比较并嵌入了锆石。锆石中含有微量的铀,这种铀以可预测的方式衰变——这意味着,亚利桑那核心可以基于铀含量进行研究。


Magnetic information in both cores allowed them to be lined up—and the Arizona dates then provided a time-line for the ancient floods and droughts embedded in the east coast core.


两个岩芯中的磁性信息,使得它们排列整齐—亚利桑那日期,为东海岸核心中埋藏的古代洪水和干旱提供了时间线。


And all that evidence confirmed the mathematical simulations: Jupiter and Venus do push us around, and thus slowly alter our orbit over hundreds of millennia 6. The details are in the Proceedings 7 of the National Academy of Sciences.


所有这些证据都证实了数学模拟试验结果:木星和金星确实在推动着地球,并因此在数千年的时间里,缓慢地改变了我们的轨道。该研究结果发表在《美国国家科学院》杂志。


Kent says the discovery also provides a new way to interpret the history of life on the planet. "It's a clock. And so being able to have a precise chronometer 8 we can relate things like speciation events, or dispersals of various life forms. It allows us to look at these things and try to understand what's driving them."


As for whether modern-day humans need to worry about this 405 thousand year oscillation?


Kent说,这一发现还为解释这个星球上的生命史,提供了一种新的方式。“这是一个时钟,所以能够拥有一个精确的计时表,我们可以将事物与物种形态事件,或各种生命形式的分散联系起来,它使我们能够观察这些事物,并试图了解是什么驱使它们。那么现代人类是否需要担心这个40.5万年的振荡?


"This is probably pretty low down the list of things to be concerned about. How much CO2 we're putting in the atmosphere, that's of a more immediate 9 concern." Because, despite our planetary neighbors’ best efforts, our orbit has barely budged 10 as we’ve observed our climate change.


“这可能是相当低概率的事情,需要关注的事情很多,我们在大气中投入了多少二氧化碳,这是一个更直接的问题。”因为尽管我们周围的邻居们,尽了最大的努力,但我们的轨道,在我们观察到气候变化时几乎没有变化。



1 geologist
n.地质学家
  • The geologist found many uncovered fossils in the valley.在那山谷里,地质学家发现了许多裸露的化石。
  • He was a geologist,rated by his cronies as the best in the business.他是一位地质学家,被他的老朋友们看做是这门行当中最好的一位。
2 observatory
n.天文台,气象台,瞭望台,观测台
  • Guy's house was close to the observatory.盖伊的房子离天文台很近。
  • Officials from Greenwich Observatory have the clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。
3 sediment
n.沉淀,沉渣,沉积(物)
  • The sediment settled and the water was clear.杂质沉淀后,水变清了。
  • Sediment begins to choke the channel's opening.沉积物开始淤塞河道口。
4 seasonal
adj.季节的,季节性的
  • The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
  • The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。
5 embedded
a.扎牢的
  • an operation to remove glass that was embedded in his leg 取出扎入他腿部玻璃的手术
  • He has embedded his name in the minds of millions of people. 他的名字铭刻在数百万人民心中。
6 millennia
n.一千年,千禧年
  • For two millennia, exogamy was a major transgression for Jews. 两千年来,异族通婚一直是犹太人的一大禁忌。
  • In the course of millennia, the dinosaurs died out. 在几千年的时间里,恐龙逐渐死绝了。
7 proceedings
n.进程,过程,议程;诉讼(程序);公报
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
8 chronometer
n.精密的计时器
  • Murchison followed with his eye the hand of his chronometer.莫奇生的眼睛追随着他的时计的秒针。
  • My watch is more expensive because it's a chronometer.我的手表是精密型的,所以要比你的贵。
9 immediate
adj.立即的;直接的,最接近的;紧靠的
  • His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
  • We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。
10 budged
v.(使)稍微移动( budge的过去式和过去分词 );(使)改变主意,(使)让步
  • Old Bosc had never budged an inch--he was totally indifferent. 老包斯克一直连动也没有动,他全然无所谓。 来自辞典例句
  • Nobody budged you an inch. 别人一丁点儿都算计不了你。 来自辞典例句
学英语单词
a favorable reception
Amfostat
anchor connector
atrap
attached type vibrator for concrete
Bakιr
basic assembler
basic equalization
BCY language
belted ammunitions
beta-lactamase
bivouackings
bloody stools
boy-man
cable access
Canterbury northwester
cash accounting method
cetane number booster
checchi
class's
close to you
coasting blockade
comcasts
continuously circulating ropeway
dystrophic calcification
Echo.
ectendotrophy
edge printer
eimeriosis
endocytosing
enrichens
evaza nigripennis
examinest
example ship
feddersen
frosted-glass
general locality
give indication
He plays the piano for his own enjoyment
horse hair broom
hot-well depression
incombined
Injuria non excusat injuriam.
intercorrelations
internal intercostals (or internal intercostal muscle)
james joyces
kapteyn's distribution
kleanthi
lamaist pagoda
lambeake
lateral forced-air cooling
latiumite
Laws of Manu
lunar seismometer
mainairs
mat-ter
Mesnil-St-Blaise
moment of sparking
multilayer adsorption
non-axisymmetrical configuration
nonvehicular
Opalina ranarum
output cascade
overhung-type motor
own a borough
oxyomus masumotoi
philalethists
political scientist
polystichum neolobatum
practicalness
primary shield water system
process mark
protest march
pseudodipteral
Puerto Dolores
pullitt
python regius
quadrangle
ratchet hob
record signal format
referential experience
reserve line
ring the shed
run into the sand s
sand dune area
secondary hyperthyroidism
single fiber electromyography
spent scrub stream
statistic descriminant technique
subregional center
taphonomically
temperature difference driving force
tender one's devoirs to
theatrical exhibition
thermomechanical method
time-stretched
vesico-uterine
vexatious suits
Vondrek smoothing method
Wagner-Jauregg treatment
wilcockson
zaobao