英语听力文摘 English Digest 481、日出日落,傻傻分不清楚（在线收听）

Sunrise or Sunset?

Yaël: Don?

Don: Yes, Yaël?

Y: We've been in this art museum for 5 hours now. And you've spent the whole time staring at that one photograph of sunset.

D: Are you sure?

Y: Of course I'm sure. You haven't budged.

D: But are you sure it's a sunset? It might be a sunrise.

Y: Ah…

D: I wonder if you can tell just by looking at it.

Y: Actually, although there’s no way to tell with certainty, there are a couple of clues you can look for.

D: Really?

Y: Sure. Let’s think about what happens to the atmosphere during the day. It warms up, which means it can hold more moisture, and traffic and other activities churn a certain amount of dust and pollutants into it.

All this extra stuff in the air can make the sunset much redder than sunrise. It can also make the light more diffuse. Artists sometimes remark that the light at sunset is softer and warmer than the sharp light at sunrise.

D: That's so?

Y: Yes, although rain or other weather can disrupt this pattern. Another clue is the ground, which cools down overnight. This can cause dew to condense out of the air, and mist to form in the air near the ground. If there’s any rising mist or dew in your photo, chances are it’s sunrise.

D: OK, then, that means this picture's... Hey, it turned out nights!

Y: The museum is closed, Don. You should have asked me earlier, instead of standing there for 5 hours.

日出还是日落？

Yaël: 我们都已经在这个美术博物馆呆了整整五个小时了，你也盯着那张日落的照片看了整整五个小时了。

Don: 你确定？

Y: 我当然能确定啦。你动都没动过。

D: 我是说，你就那么确定这是拍的日落？它也有可能是日出啊。我倒想知道你单凭看照片就能下定论了。

Y: 事实上呢，虽然说不能完全肯定的进行辨别，但是我们还是有两条线索可循。

D: 真的？

Y: 当然。想想白天的时候空气会发生什么样的变化。空气不断升温，这就意味着空气中会含有更多的水分。另外，交通以及其他的活动会将大量的粉尘及污染物质带入空气当中。

空气中多出来的水分、粉尘等等物质会使日落看起来比日出颜色更红。同时，这些物质会让光线扩散得更开。艺术家们有过这样的评论——日落时的光芒相对于日出时强烈的光线来说，更为柔和、温暖。

D: 是这样啊？

Y: 恩。但是，有的时候下雨或其他的天气会对这种辨别方法有所影响。别担心，我们还有另一条线索！这条线索便是土地，晚上，土壤温度会慢慢的降低。这样一来，空气中便会凝结出露珠，为地表蒙上一层薄雾。所以说，如果说照片中有上升的雾气或是露珠，那么肯定就是日出了。

D: 那么，照这方法来看……嘿，这是日落！

Y: 看吧，博物馆都要关门了。你该早些问我这个问题的，也不至于在这里站上整整5个小时了。