Rainbows and other shiny things

[Glaurung]

I was reminded today of a website you might enjoy. Atmospheric Optics is about rainbows, ice halos, and many other optical effects that occur when sunlight meets rain drops or ice crystals. There's a wide range of amazing photographs, along with clear and accurate descriptions of the physics involved. But you don't need to understand the physics in order to enjoy the pictures.

[Glaurung]

There's a good example of one of the more common effects, so-called "sun dogs", reported today from Chelyabinsk in Russia.

[Jubal]

There was quite an influential article about Constantine written a few years back that suggested that one of these pretty lighting effects was what was reported as his "vision in the sky" that precipitated his conversion to Christianity. Whilst I'm a sceptic about the whole sudden conversion narrative, you can see how halos and such things could have been interpreted in a very awe-inspired way!

[Glaurung]

Here's a BBC News article with a couple of pictures of one of the less common optical effects, the circumzenithal arc, otherwise described as an "upside-down rainbow".