ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

太阳初生光芒羸弱 地球何以欣欣向荣? – 译学馆
未登录,请登录后再发表信息
最新评论 (0)
播放视频

太阳初生光芒羸弱 地球何以欣欣向荣?

The Faint Young Sun Paradox!

嗨 我是艾米丽
Hi, this is Emily.
在1972年
In 1972,
卡尔•萨根与一位同事首次提出了一种观点 颇为知名
Carl Sagan and a colleague discovered something that’s come to be known
叫做“黯淡太阳悖论”:
as the faint young sun paradox:
根据星体物理学
according to stellar physics,
太阳因为内核氢聚变在增强 所以会随着时间流逝 会越发明亮
our sun has been growing brighter over time, thanks to increasing hydrogen fusion in the star’s core.
这就意味着
This means that the
早期地球受到的太阳光照 比起现在而言 大概要暗淡25%
sun that shined on early Earth was roughly 25% dimmer than today’s sun,
这造成了 幼年期的地球 颇为寒冷
which should have kept our baby planet cool
足以 使地球两极冰层扩张
enough for ice at the poles to grow and
继而 反射更多的阳光
reflect more sunlight and
让地球的寒冷进一步加剧
cool the planet further –
于是 不折不扣的“滚雪球效应”就此产生
producing a literal snowball effect and
最终会导致地球变成一个大冰块
turning Earth into a big ice cube.
但是
BUT:
根据地球岩石和化石证据表明
according to rock and fossil evidence,
实际上早期的地球温暖适宜 水分充足 是生物的乐园
ancient Earth was actually a melty, warm,watery haven for life,
使得低级单细胞生物得以在此繁衍生息
where simple single-celled organisms developed and thrived.
于是 便形成了悖论:
Hence the paradox –
太阳初期光芒羸弱 地球何以温暖适宜?
how could the sun be dim but the earth warm?
对此 科学家给出了各种各样的解释
Scientists have proposed a range of possible explanations,
不过 其中最有可能的是:
but the most likely one is that
地球早期大气层 存在一层或更多的超级隔绝性气体
Earth’s early atmosphere included one or more ultra-insulating gases
借此 让地球表面 反常地保持着 温暖舒适
that kept its surface unseasonably toasty.
尽管 我们还无法确切地了解
We still don’t know for sure
这些气体都是什么
what those gases were or
这些气体来自何处
where they came from,
但是 科学家们对此提出了非常有趣的想法:
but scientists have been toying with an intriguing possibility:
产生地球这个巨大温室效应的 不论是什么事物 其作为孕育生命的条件 都至关重要
that whatever created Earth’s megagreenhouse effect also supplied key ingredients for life.
(关于这些气体)有这样一个假说:
One hypothesis is that
太阳系形成残留的岩石碎片 持续不断地轰击 让早期的地球 颇为炙热
a constant barrage of rocky debris left over from the creation of the solar system melted sizable chunks of earth,
从而 释放出温室气体
releasing greenhouse gases like
比如 二氧化碳 甲烷
carbon dioxide and methane,
继而 把硫元素
and drawing sulfur
— 某些氨基酸的基本成分
– an essential component of some amino acids
带到了地表
– up to the surface.
另外有一个假说 特别棒
Another out-of-this-world hypothesis
假说提出 太阳本身(是始作俑者)
points to the sun itself.
太阳表面的磁暴会向宇宙空间释放大量高能粒子
Magnetic storms on the sun’s surface unleash streams of high-energy particles into space.
这些高能粒子 在现在被称作“太阳风”
Today, these so-called solar winds
太阳风不仅能够扰乱地球磁场
can disrupt Earth’s magnetic shield
而且可以进入大气层 与气体相互作用
enough to penetrate the atmosphere and interact with gases,
继而 产生极光现象
giving rise to the Auroras.
不过 追溯到太阳幼年期
But back when our sun was a baby,
那时 太阳发起脾气来 要狂暴得多
it threw much wilder tantrums,
大量高能粒子频繁释放
hurling frequent streams of high-energy particles
与地球原始大气层相互作用
that interacted with Earth’s primordial atmosphere
导致两种气体大量生成:
to create large amounts of two gases:
第一种是一氧化二氮 温室效应效果为二氧化氮的300倍
nitrous oxide, a greenhouse gas 300 times as powerful as carbon dioxide,
第二种是氰化氢 有毒性 然而对生命基础物质的生成却有促进作用
and hydrogen cyanide, a poison that can, ironically, also help produce some basic building blocks of life.
不论真实情况如何
Whatever the real story,
都能肯定地说
it’s safe to say that
早期的地球 面对年轻黯淡的太阳 通过某种方式 成功缔造出了生命的美好家园
our early Earth somehow managed to create a perfect home for life under the faint young sun.
也能肯定地说
It’s also safe to say that,
由于太阳在未来会持续燃烧 且越发明亮
as our sun continues to burn ever brighter into the future,
因此 地球会滚雪球般越发变得炙热
Earth will snowball in another hotter direction,
最终 在老迈太阳最明亮的照耀下 水源干会涸 生命会灭绝
and eventually water and life will boil away under the bright old sun.
本视频赞助者 是海辛-西蒙斯基金会:
This video was supported by the Heising-Simons Foundation:
发现知识 发现机会 发现可能
Unlocking knowledge, opportunity, and possibilities.
想更多了解基金会及其旗下科学项目
To learn more about the Foundation, and about its Science program,
这些科学项目主要资助自然科学基本性研究
which supports fundamental research primarily in the physical sciences,
请访问www.heisingsimons.org网址
visit www.heisingsimons.org

发表评论

译制信息
视频概述

太阳初生光芒羸弱 地球何以欣欣向荣?太阳初生光芒羸弱 地球何以欣欣向荣?

听录译者

收集自网络

翻译译者

翻译爱好者山人乙

审核员

译学馆审核团D

视频来源

https://www.youtube.com/watch?v=qbnaes8X4iQ

相关推荐