宇宙时空之旅（2014）

Cosmos: A SpaceTime Odyssey S01E09

Part 5 April 25, 2021, 12:40 p.m.

变成了一片荒芜
gave way to a sparser landscape.
一些擅长在树上生活的物种
Some species that were highly specialized for life in the trees
走向灭绝
became extinct.
但是有一些物种
But the generalists, the ones that could find a way
不管生活给予它们什么
to make a living no matter what life threw at them,
它们都能适应并进化
endured and evolved.
我们的祖先就曾进入地下
Our ancestors had once burrowed deep in the ground
来躲避地面上的食肉动物
to avoid predators who stalked the surface.
但是恐龙灭绝以后
But when the dinosaurs perished,
它们开始在白天出来活动
they emerged into the daylight,
许多年后在树上
and over the eons, made new lives
创造出了新生命
in the branches of the trees.
它们发达的对生拇指和脚趾
They developed opposable thumbs and toes
可以让它们从一棵树荡到另一棵树
for swinging from branch to branch,
穿过宽广的树冠
across the broad canopy of treetops,
就能找到它们需要的
where all their needs were fulfilled.
它们也能直立行走但仅限短距离
They could also walk upright, but only for short distances.
四周有这么多树它们不必走太远
With so many trees around, they didn't have to go very far.
然而变冷以后
But then it got colder,
树变得稀疏起来
and the trees thinned out,
广阔的大草原出现了我们的祖先
broad grasslands sprang up, and our ancestors
不得不♥穿♥过草原来寻找食物
were forced to traverse them in search of food.
在热带草原上生活
You needed a totally different skill set
你需要完全不同的技能
to make it on the savanna.
从前
In the old days,
你能高高坐在树枝上
you could sit perched on your tree branch
在安全距离观察大型猫科动物
and watch the big cats from a safe distance.
现在你也置身于同样危险的境地
Now you were playing on the same dangerous field.
只有那些进化出在必要时候
The survivors were those who evolved the ability
用后肢长距离行走
to walk great distances on their hind legs
并且能跑的才会幸存下来
and to run when necessary.
这改变了它们
This changed the way
看世界的方式
they looked at the world.
手和胳膊不再用于行走
Hands and arms were no longer tied up with walking.
它们可以自♥由♥采集食物捡起棍棒和骨头
They were free to gather food and pick up sticks and bones.
这些可以用为武器和工具
These could be used as weapons and tools.
试想一下
Think of it...
地球另一端的一小块土地的
A change in the topography of a small piece of land
地形变化改变了洋流
half a world away reroutes ocean currents.
非洲变得又冷又干
Africa grows colder and drier.
大部分树都无法适应新的气候
Most of the trees can't withstand the new climate.
那些在树里生活的灵长类
The primates who lived in them
不得不寻找新的住所很快
have to seek other homes, and before you know it,
它们就学会了用工具重建家园
they're using tools to remake the planet.
地球决定着人类命运
The Earth has shaped the course of human destiny,
但遥远世界的无形引力也是如此
but so has the invisible pull of distant worlds.
行星用我们没有想到的方式
The planets have influenced our lives,
影响着我们的生活
but not in the way you think.
金星的引力
The gravitational pull of Venus--
小却距离近
small but close--
而木星的引力遥远但却力量巨大
and that of Jupiter-- distant but massive--
将地轴倾斜
tilted the Earth's axis this way and that...
并非常轻微地扭曲了轨道的形状
and ever so slightly tweaked the shape of its orbit.
这周期性地改变了
This periodically altered
落在北极冰盖边缘的
the amount of sunlight
阳光的多少
falling on the edge of the northern ice cap.
有时它使那里的夏天更冷
Sometimes it made the summers there colder,
冰川每年都
and the glaciers advanced southward
向南移♥动♥
from one year to the next,
刮削摩擦
grinding and scraping,
压碎路上的一切障碍
and crushing everything in their path.
我们称之为冰河时代
That's what we call an ice age.
其他时候地轴和轨道的改变
At other times, changes in Earth's axis and orbit
使得北极的夏天更温暖
made the Arctic summers warmer.
融化的冰盖开始退去
And the melting glaciers began to retreat.
想象一下我们的祖先为了在这种气候巨变中
Imagine how resourceful our ancestors had to be
存活下来是多么机智
in order to survive these radical changes in climate.
每个冰河时期
With each glacial period,
冰川增多海洋减少
the ice sheets grow at the expense of the oceans;
世界海平面下降了约120米
the world sea level falls by more than 400 feet,
在大♥陆♥边缘
uncovering wide areas of land
大量陆地露出水面
along the edges of the continents.
一万五千年到两万五千年以前
15 to 25,000 years ago,
冰川后退的时候
there was a period when the ice receded,
陆桥暂时显露出来
exposing a temporary land bridge.
去往地球另一端的通道打开了
The gateway to the other half of the planet swings open.
流浪者们穿过陆桥
Bands of wanderers crossed the land bridge
到了北美和再南一点的地方
to North America and parts south.
大约一万年前气候和海平面的
About 10,000 years ago, the manic swings
强烈波动暂停了
of the climate and sea levels came to a stop.
新的气候温和的时代♥开♥始了
A new and gentler climate age began.
也就是我们现在生活的时代
It's the one we live in now.
随着大量冰川融化
When the great ice sheets melted,
海平面上升到了现在的高度
the sea rose to its present height
而且河水从高地上带来了淤泥
and the rivers carried silt from the highlands
当它们到达大海时
to build great delta plains
就会形成大♥片♥三角洲平原
where they met the sea.
在那些土地肥沃的地方
On those fertile plains,
我们学会了一种新的生活方式
we learned a new way of life...
我们学会了种植食物来养活自己
how to grow things, to feed ourselves and more.
对我们大部分人来说
For most of us, this meant an end
这意味着数百万年流浪的结束
to a million years of wandering.
行星间的相互作用
The way the planets tug at each other,
地球表面的移♥动♥
the way the skin of the Earth moves,
那些变化对气候
the way those motions affect climate
和生命智力演化的影响
and the evolution of life and intelligence--
它们结合在一起
they all combined to give us the means
使得三角洲里的淤泥
to turn the mud of those river deltas
变成了最初的文明
into the first civilizations.
没有什么比得上间冰期
There's nothing like an interglacial period,
冰河时代中的温和间歇时期
one of those balmy intermissions in an ice age.
好消息是这个时期
And the great news is that this one is due to last
还要持续五万年
for another 50,000 years.
这对人类再好不过
What a break for our kind.
只有一个问题
Just one problem.
我们好像在不停地燃烧那些
We can't seem to stop burning up all those
从石炭纪就被埋在地里的树
buried trees from way back in the Carboniferous Age,
就是煤炭
in the form of coal;
还有古代浮游生物的遗骸
and the remains of ancient plankton,
也就是油和天然气
in the form of oil and gas.
如果我们可以停止燃烧
If we could,
从气候方面考虑我们就大功告成了
we'd be home free, climate-wise.
然而我们却在以气候大灾难后
Instead, we're dumping carbon dioxide into the atmosphere
从未有过的速度
at a rate the Earth hasn't seen
源源不断地往大气中排放二氧化碳
since the great climate catastrophes of the past,
而气候大灾难导致了大灭绝
the ones that led to mass extinctions.
我们好像没法停止燃烧燃料
We just can't seem to break our addiction to the kinds of fuel
这会给我们带来恐龙时代时的气候
that'll bring back a climate last seen by the dinosaurs;
这种气候会淹没沿海城市对我们的
a climate that will drown our coastal cities and wreak havoc
环境和生存能力造成严重破坏
on the environment and our ability to feed ourselves.
太阳的光辉始终照耀着我们
All the while, the glorious sun
太阳能是免费的能源
pours immaculate, free energy down upon us;
取之不尽用之不竭
more than we will ever need.
为什么我们不能总结前人一代代
Why can't we summon the ingenuity and courage
传下来的智慧和勇气
of the generations that came before us?
恐龙无法预见小行星的到来
The dinosaurs never saw that asteroid coming.
而我们有什么借口
What's our excuse?
在灭绝大厅
There's a corridor
有一条走廊
in the Halls of Extinction that is, right now,
空旷没有任何标记
empty and unmarked.