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格林兰岛的海贝如何知道天气 – 译学馆
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格林兰岛的海贝如何知道天气

How These Sea Shells Know the Weather in Greenland

每个海贝实际上都非常 非常小
Each of these sea-shells is in fact really, really tiny, because each was once home to
因为每一个都曾是微小单细胞海洋生物有孔虫的家
a tiny single-celled marine life form called a foram.
尽管它们没有眼睛 大脑或四肢
Though they don’t have eyes or brains or limbs, forams somehow manage to pull ingredients
依然设法从海水中拖取材料 将它们堆在碳酸钙矿物制成的房子中
from seawater and stack them together into houses made out of the mineral calcium carbonate.
更酷的是 每个小房子最终都有一个写进其中的数字
Even cooler, each little house ends up with a number written into it that tells us how
告诉我们地球上有多少冰雪
much ice and snow there is on Earth.
对——一个单细胞的海洋生物知道我们整个星球上有多少冰雪混合物
That’s right – a single-celled sea creature knows how much combined snow and ice there
在所有山顶和冰原冰川上
is on all the mountaintops and ice sheets and glaciers on our entire planet!
听上去很疯狂 但这是真的 接下来是它的发生原理:
Crazy, but it’s true. Here’s how it happens:
有孔虫壳上的数字来自两种他们从海水带走的氧
The number in the forams’ shells comes from the two types of oxygen they pull from seawater
一种是普通的有8个质子和8个中子的 而另一种重氧
– the regular kind, with eight protons and eight neutrons, and the heavy kind, with eight
有8个质子和10个中子
protons and TEN neutrons.
由普通氧原子组成的水分子要比重氧水更轻和更敏捷
H-TWO-O molecules with regular oxygen are slightly lighter and less sluggish than H-TWO-Os with heavy oxygen,
它们更易从海洋表面蒸发
so they’re more likely to evaporate from the ocean’s surface and
在云层里中游荡
go gallivanting around in clouds.
因为冰原上的所有冰都直接来自云层
And since all the ice in the ice sheets comes directly from clouds,
冰原的作用就是一个普通氧的储存设施
the ice sheets act as a kind of storage facility for regular oxygen.
全球气候越冷 冰原储存的普通氧越多
The colder the global climate, the more regular oxygen the ice sheets store, and the less
被留在海洋的就越少
is left behind in the oceans.
在建造自己的贝壳时 有孔虫有效地从海水中的重氧夺得一定比率的普通氧
As they build their shells, forams effectively capture the ratio of regular oxygen to heavy
我们读那个比率 就能算出在极点有多少冰
oxygen in the seawater, and we can read that ratio back to figure out how much ice there
以及全球平均气温
is at the poles, and what the average global temperature is.
当然 我们也能直接测量
Of course, we can also just measure those things directly, but our thermometers and
但是我们的温度计和卫星却只能告诉我们现在的情况
satellites can only tell us what’s going on right now.
另一方面 有孔虫已经记录了这个数据亿万年
Forams, on the other hand, have been recording this data for hundreds of millions of years,
他们的档案在海底慢慢堆积起来
and their archives have been slowly piling up on the seafloor.
所以通过下钻古代沉积物并拉取大块长条样芯
So by drilling down and pulling up a big long core of ancient sediment, we can recover an
我们能找到几乎连续的记录 记录地球的温度随着时间的变化是如何上升 下降又上升
almost continuous record of how Earth’s temperature has gone up and down and up and
如此循环往复
down and up and down etc over time.
事实上 我们能知道这么多关于我们行星过去的气候
In fact, we owe most of what we know about our planet’s past climate to these tiny
要归功于这些微小而又愚笨的海员和他们小而美的家园
brainless seafarers and their tiny, beautiful homes.
这个视频由Heising-Simons基金会支持:开启知识 机会
This video was supported by the Heising-Simons Foundation: Unlocking knowledge, opportunity,
和可能性
and possibilities.
想要更多地了解该基金会
To learn more about the Foundation,
及其科学项目(主要关于物理科学的基础研究)
and about its Science program, which supports fundamental research primarily in the physical sciences,
请登录 www.heisingsimons.org
visit www.heisingsimons.org.

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这是关于怎样通过海贝来了解地球过去的气候的科普小知识

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https://www.youtube.com/watch?v=oaOfeSJZ3lY

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