TED演讲:抬头看一看平时忽视的变化(3)（在线收听）

This is our earth at night, and it is one of the most striking examples of how we have affected our planet on a global scale.

这是夜晚的地球，这是人类在全球范围内对地球造成显著影响的例子之一。

You can see light spidering out across the globe everywhere.

你可以看到光亮散播到了全球的各个角落，

Now, of course, there are broad expanses of ocean that are still dark,

当然，现在广阔的海洋依旧处于黑暗中，

and in many underdeveloped areas there's still darkness.

很多不发达的地区看起来也是漆黑一片。

But you'll notice that this is a pretty global effect.

但你会发现这其实已经成为了全球现象。

We tend to think, when we think of places being lit up, of very extreme examples -- Times Square, the Vegas Strip.

当提到灯火通明的地方时，我们总会想起那些最极端的例子，比如时代广场、拉斯维加斯大道。

But really what that picture shows you is that it's not just these extreme examples, it's anywhere that uses outdoor lighting.

但那张整个地球的照明情况图片显示的不仅仅是这几个极端个例，而是任何使用户外照明的地方。

This tends to be a really dramatic effect on the ground.

这往往给地球表面带来真正巨大的影响。

To understand why, all you really have to do is think about the shape of a lightbulb.

想知道为什么，你只需想想灯泡的形状。

The lightbulb, for all practical purposes, is more or less round.

为了实用的目的，灯泡基本上都是圆的。

This is great for its original intended purpose of lighting up the indoors.

这正符合它最初的目的，室内照明。

You turn it on, light goes everywhere. An individual light bulb can light up your whole room, more or less.

你打开灯，灯光照射到房间的每个角落。一个灯泡就能照亮整个房间，只是明暗程度的差异。

Now, that's great if you're lighting the indoors, but in its application in outdoor lighting,

如果你想照亮室内，这确实非常有效；但当我们用于室外照明时，

that traditional shape of the light bulb, the sort of globe that spreads light everywhere, is actually very inefficient.

传统的灯泡形状，即那种向四周传播光线的球形灯泡，其实是十分低效的。

When you're outdoors, mostly what you care about is lighting the ground beneath you and your immediate surroundings.

当你身处室外时，你最关心的是照亮你脚下的地面和周围的环境。

All of that light that gets scattered outwards and upwards doesn't actually help you light the area around you.

所有那些分散向外或向上的光，都并不能帮你有效地照亮你周围的区域。

What it does is scatters up into the sky and becomes what we call "light pollution."

它只是将光线散射到天空，造成我们所说的“光污染”。

Even if you don't care anything about stargazing, this should worry you,

即使你不在意星象观测，你也应该关心光污染，

because it means that 60-70% of the energy we use to light the outdoors is wasted by blotting out the stars.

因为，它意味着我们用于室外照明的60-70%的能量被浪费在屏蔽夜晚的星光了。