Where Do Rainbows Come From? 彩虹来自何方

Throughout history, rainbows have been a source of mystery and legend. Rainbows are also important symbols in a number of cultures around the world.

In the Old Testament of the Bible, for example, God shows Noah a rainbow to let him know that the Flood is over and that he will never destroy the earth again with flooding. An ancient Mayan book also tells of a rainbow signaling a new age after the destruction of the earth.

In a myth from Germany, the rainbow is the palette that God used to paint the birds. Some Native American groups believed that rainbows were made from wild flowers. In other traditions, the rainbow is the hem of a particular god's coat.

In an ancient Japanese myth, the rainbow is a bridge from heaven to earth. The first man and woman walked down this bridge to learn the ways of the world.

Today, we know exactly how rainbows are made. In the seventeenth century, the scientist Isaac Newton and the mathematician and philosopher Rene Descartes analyzed them very carefully. They concluded that rainbows were caused when sunlight was broken up as it passed through raindrops.

When it rains, the colors that make up white light separate because they bend at different angles when they pass through water. The result is the full spectrum of colors the human eye can see, as well as some that it cannot; at the outermost edges of a rainbow lie ultraviolet and infrared light.

Everyone knows that we can sometimes see rainbows on a rainy day. However, you actually have a chance of seeing a rainbow anytime there is light behind you and water in the air in front of you. So, if you want to know what it feels like to have the power of a god, get a spray bottle, stand with your back to the sun, and create a rainbow!

有史以来，彩虹一直都是神话和传奇的源泉，在世界多种文化中，彩虹还是重要的象征。

举例来说，在《旧约》里，上帝通过彩虹让诺亚知道大洪水已经结束， 而且他再也不会用大洪水来毁灭地球。一部古老的马雅典籍也讲述彩虹标志着在地球毁灭后新世纪的来临。

在德国一则神话故事里，彩虹是上帝用来为鸟儿上色的调色盘。一些美国土著群体认为彩虹是由野花做成的。在其它传说里，彩虹是某一位神祗外衣的褶边。

在古老的日本神话里，彩虹是连接天堂和人间的桥梁，人类的第一个男人和女人一起从这座桥上走下来，学习人间世事。

现在，我们已确切知道彩虹是怎样形成的。在十七世纪，科学家牛顿和数学家兼哲学家的笛卡尔，就非常仔细地分析过彩虹，他们断定-彩虹的形成是因为阳光穿过雨滴时被打散所致。

下雨时，那些构成白色光的颜色穿过水滴时以不同的角度被折射而散开，就形成了完整的光谱，其中有些颜色肉眼能看得到，有些看不到；彩虹的最外围是紫外线和红外线。

大家都知道，有时在雨天我们能看到彩虹。其实，只要你身后有光线，面前的空气中有水分，任何时候都有机会看到彩虹。所以，如果你想试试当上帝的感觉，就拿一瓶喷雾器，背向太阳，自己做一道彩虹吧！