Sunday, March 12, 2006

South Pole phenomenon: fata morgana

A researcher stationed in Antarctica writes about seeing an optical phenomenon called "fata morgana" (link, then scroll down to what is currently the first entry. Via boingboing.):

Today at lunch, we had the chance to see a very cool atmospheric optical effect at the horizon called fata morgana. Here is a historical explanation of where the name comes from. "Fata Morgana is Italian for 'Fairy Morgan', and as legend goes was the half-sister of King Arthur. She was said to live beneath the water and had magical powers capable of building huge cities out of thin air and the make them disappear. There's a certain place in Italy, when in Reggio looking across the Straits of Messina, where this legend has staying power in the eyes of numerous witnesses." This optical illusion is the result of refraction of light though the atmosphere. It happens when a layer of cold air is just above the ground and a layer of warmer air is above it. This causes a mirage which makes an object (here just snow at the horizon) appear larger or more elevated than it really is. In this case, it appears as a cliff at the horizon, as if a giant iceberg had suddenly moved it. It is quite amazing. Even with binoculars, you see it an[d] you think it real.

Anonymous sue wheeler on Sun Mar 12, 10:47:00 PM:
I have heard that the ancient city of Alexandria would appear to sailors when their ships were still far out to sea, approaching the Nile delta. It hovered over the water. There is a place on the south shore of Lasqueti Island where you can see (under the right atmos. conditions) a projection of the high rises of the West End of Vancouver, hovering upside down over Vancouver Island. One elderly friend told me that she was hiking along that shore and saw this, and thought, "Well now I am really starting to lose it," and mentioned it to no one, then another friend said "There's this place near here, where you can see..." and described this Fata Morgana of Vancouver. A relief, and a funny story, for my friend. I have seen boats some distance away hovering in the air above the horizon, steaming along.