佛罗里达州惊现彩虹云奇观

So-called "fire rainbows" are neither on fire nor are they rainbows, but they sure are stunning.

所谓的火焰彩云既不是火也不是彩虹，但绝对是极为壮观的自然景象。

They are technically known as iridescent clouds, a relatively rare phenomenon caused by clouds of water droplets of nearly uniform size, according to a release by NASA. These clouds diffract, or bend, light in a similar manner, which separates out light into different wavelengths, or colors.

据美国国家航空和宇宙航行局，火焰彩云的学名叫做彩虹云，是一种非常罕见的自然现象，这一现象是由于云层中聚集了大量均匀大小的水滴而造成的。这些云层以相似的方式衍射了太阳光，然后析出不同波长的太阳光。

That makes them similar to rainbow-colored glories, which are also formed by diffraction, and also produce an oscillating pattern of colors ranging from blue to green to red to purple and back to blue again.

这使它们看起来有点像彩虹的七彩光芒，这些七彩光芒就是由于发生了衍射才形成的，而也是由于衍射现象才使得彩云的颜色从蓝色到绿色到红色到紫色再到绿色而变幻无穷。

The phenomenon was captured in this spectacular photo taken on Tuesday (July 31) in the clouds over South Florida.

这一奇观于7月31日在弗罗里达南部上空被照片记录了下来。

Although iridescent clouds have rainbow-like colors, the way light is scattered to produce them is slightly different. Rainbows are formed by refraction and reflection. Diffraction, though, involves light waves being scattered into a ring-like pattern.

尽管彩虹云具有彩虹般的光芒，但与彩虹形成的方式却是不大一样的。彩虹是由于发生了折射和反射现象而形成的。而彩虹云是由于发生了衍射现象才形成的。

As with other iridescent objects, like peacock feathers, the color changes depending upon one's position relative to the sun and the object.

其他的七彩物体，比如孔雀羽毛，其颜色变幻就取决于人们与太阳和该物体之间的相对位置。

Iridescence usually occurs in newly formed clouds. That appears to be the case here as well.

彩虹云通常形成于新形成的云层上。佛罗里达看到的彩虹云也是如此。