A guide to the energy of the Earth - Joshua M. Sneideman
地球能量指南 - Joshua M. Sneideman
1,209,072 views ・ 2014-06-30
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翻译人员: Winter Wei
校对人员: Xiaoou Chen
00:07
Energy is all around us,
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我们周围充满了能量,
00:09
a physical quantity that follows
precise natural laws.
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一种严格遵循自然规律的物理质量。
00:14
Our universe has a finite amount of it;
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宇宙中的能量是有限的;
00:16
it's neither created nor destroyed
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能量不会产生也不会毁灭,
00:18
but can take different forms,
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但能以不同形式存在,
00:20
such as kinetic or potential energy,
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如动能和势能,
00:22
with different properties
and formulas to remember.
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有不同的性质和公式要记。
00:25
For instance,
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比如,
00:27
an LED desk lamp's 6 Watt bulb
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一个LED(发光二极管)灯的6瓦灯泡
00:29
transfers 6 Joules
of light energy per second.
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每秒转移6焦耳的光能。
00:33
But let's jump back up into space
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但让我们回到宇宙空间
00:35
to look at our planet,
its systems, and their energy flow.
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看一看我们的星球,它的系统,及其能量流。
00:39
Earth's physical systems include
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地球的物理系统包括
00:41
the atmosphere, hydrosphere,
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大气层,
水圈
00:44
lithosphere, and biosphere.
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岩石圈,
和生物圈。
00:46
Energy moves in and out of these systems,
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能量在这些系统之间出入流动,
00:49
and during any energy
transfer between them,
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能量在它们之间转换的时候,
00:52
some is lost to the surroundings,
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有些在周围事物间流失了,
00:54
as heat, light, sound,
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比如热、光、声、震动,或活动。
00:57
vibration, or movement.
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00:59
Our planet's energy comes from
internal and external sources.
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我们星球的能量来自于
内部和外部的能源;
01:03
Geothermal energy
from radioactive isotopes
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地热能来自于放射性同位素
01:06
and rotational energy
from the spinning of the Earth
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以及地球自转时产生的旋转能,
01:09
are internal sources of energy,
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这些是内部能源。
01:11
while the Sun
is the major external source,
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而太阳则是最主要的外部能源,
01:14
driving certain systems,
like our weather and climate.
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影响了一些如
天气和气候的系统。
01:18
Sunlight warms the surface and atmosphere
in varying amounts,
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阳光不同程度地
温暖着表面与大气层,
01:21
and this causes convection,
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这就引起了对流,
01:23
producing winds
and influencing ocean currents.
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引起了风并影响了海洋气流。
红外线辐射,从地球温暖的表面
01:27
Infrared radiation, radiating out
from the warmed surface of the Earth,
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散发出来
01:31
gets trapped by greenhouse gases
and further affects the energy flow.
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被温室气体笼罩住
从而进一步影响能量流动。
01:36
The Sun is also the major source
of energy for organisms.
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太阳也是一个主要的能源
对于有机体而言。
01:40
Plants, algae, and cyanobacteria
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植物、海藻类,和蓝细菌
01:42
use sunlight to produce organic matter
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用阳光从二氧化碳和水中
01:45
from carbon dioxide and water,
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产生有机物质,
01:48
powering the biosphere's food chains.
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为生物圈的食物链提供能量。
01:50
We release this food energy
using chemical reactions,
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我们由化学反应
释放食物中的能量,
01:54
like combustion and respiration.
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比如氧化和呼吸。
01:56
At each level in a food chain,
some energy is stored
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在食物链的每一层,
一些能量都被储存于
02:00
in newly made chemical structures,
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新产生的化学结构中,
02:02
but most is lost to the surroundings,
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但大部分能量都流失在周遭了,
02:04
as heat, like your body heat,
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一些成为热量,如你身体散发的热量,
02:06
released by your digestion of food.
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在你身体消化食物的时候被释放出来。
02:09
Now, as plants are eaten
by primary consumers,
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当植物被主要消费者吃掉的时候,
02:12
only about 10% of their total energy
is passed on to the next level.
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全部能量中只有大概10%
被传输到下一层。
02:17
Since energy can only flow
in one direction in a food chain,
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由于在食物链里
能量只向一个方向流动,
02:21
from producers on to consumers
and decomposers,
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从生产者到消费者再到分解者,
02:24
an organism that eats lower
on the food chain,
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吃食物链中比之低级的生物,
02:26
is more efficient than one higher up.
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比高层的效率更高。
02:29
So eating producers
is the most efficient level
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所以动物得到能量的方式中,
02:32
at which an animal can get its energy,
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吃生产者是效率最高的。
02:34
but without continual input of energy
to those producers,
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但如果生产者
不能持续得到能量供应,
02:38
mostly from sunlight,
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主要是从阳光中,
02:40
life on Earth as we know it
would cease to exist.
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我们所知的地球生命
将不复存在。
02:43
We humans, of course, spend our energy
doing a lot of things besides eating.
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我们人类用我们的能量
做许多吃东西以外的事情。
02:47
We travel, we build, we power
all sorts of technology.
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我们旅行,我们做东西,我们发明各种科技。
02:51
To do all this,
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为了做这些事,
02:53
we use sources like fossil fuels:
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我们使用矿物燃料:
02:54
coal, oil, and natural gas,
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煤炭、石油,和天然气,
02:57
which contain energy
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这些都含有能量
02:59
that plants captured
from sunlight long ago
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是常年从阳光中
所吸取的能量
03:02
and stored in the form of carbon.
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并以碳的形式保存着。
03:04
When we burn fossil fuels in power plants,
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当我们在动力厂燃烧矿物燃料时,
03:07
we release this stored energy
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我们就释放出这些保存的能量
03:09
to generate electricity.
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用来发电。
03:11
To generate electricity,
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在发电过程中,
03:13
heat from burning fossil fuels
is used to power turbines
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燃烧矿物燃料产生的热量
用来给涡轮发电
03:16
that rotate magnets,
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涡轮旋转磁铁,
03:18
which, in turn, create
magnetic field changes
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这样就产生了相对于线圈的
03:21
relative to a coil of wire,
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磁场变化,
03:23
causing electrons to be
induced to flow in the wire.
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于是在电线里产生电子。
03:27
Modern civilization depends on our ability
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现代文明依赖于我们
03:30
to keep powering that flow of electrons.
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持续为供电提供能量。
03:33
Fortunately, we aren't limited
to burning non-renewable fossil fuels
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幸运的是,我们并不局限于
燃烧不可再生的矿物燃料
03:37
to generate electricity.
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来发电。
03:39
Electrons can also be induced to flow
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电子也可以被促使流动
03:41
by direct interaction
with light particles,
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当直接与光子接触当时候,
03:44
which is how a solar cell operates.
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这也是太阳能电池的操作原理。
其他的可再生能量资源,
03:47
Other renewable energy sources,
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03:49
such as wind, water,
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比如风能、水能、地热能,和生物燃料
03:51
geothermal, and biofuels
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03:53
can also be used to generate electricity.
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都可以用来发电。
地球对能源对要求在增长,
03:57
Global demand for energy is increasing,
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03:59
but the planet
has limited energy resources
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但地球上只有有限的资源
04:02
to access through a complex
energy infrastructure.
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是可通过复杂的资源结构得到的。
04:05
As populations rise,
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当人口在增长,
04:07
alongside rates of industrialization
and development,
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工业的发展也在随之增长,
04:10
our energy decisions grow
more and more important.
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我们对于能源的决定也变的越发重要。
04:13
Access to energy
impacts health, education,
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得到能源
影响着健康、教育、政权,和社会经济的处境。
04:16
political power, and socioeconomic status.
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04:19
If we improve our energy efficiency,
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如果我们能提高能源效率,
04:22
we can use our natural resources
more responsibly
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我们就能更可靠的使用天然资源
04:25
and improve quality of life for everyone.
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并提高每个人的生活质量。
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