Where Do Rainbows Come From? 彩虹來自何方

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!

有史以來，彩虹一直都是神話和傳奇的源泉，在世界多種文化中，彩虹還是重要的象征。

舉例來說，在《舊約》里，上帝通過彩虹讓諾亞知道大洪水已經結束， 而且他再也不會用大洪水來毀滅地球。一部古老的馬雅典籍也講述彩虹標志著在地球毀滅后新世紀的來臨。

在德國一則神話故事里，彩虹是上帝用來為鳥兒上色的調色盤。一些美國土著群體認為彩虹是由野花做成的。在其它傳說里，彩虹是某一位神祗外衣的褶邊。

在古老的日本神話里，彩虹是連接天堂和人間的橋梁，人類的第一個男人和女人一起從這座橋上走下來，學習人間世事。

現在，我們已確切知道彩虹是怎樣形成的。在十七世紀，科學家牛頓和數學家兼哲學家的笛卡爾，就非常仔細地分析過彩虹，他們斷定-彩虹的形成是因為陽光穿過雨滴時被打散所致。

下雨時，那些構成白色光的顏色穿過水滴時以不同的角度被折射而散開，就形成了完整的光譜，其中有些顏色肉眼能看得到，有些看不到；彩虹的最外圍是紫外線和紅外線。

大家都知道，有時在雨天我們能看到彩虹。其實，只要你身后有光線，面前的空氣中有水分，任何時候都有機會看到彩虹。所以，如果你想試試當上帝的感覺，就拿一瓶噴霧器，背向太陽，自己做一道彩虹吧！