Location Taken: North Bay, Ontario
Time Taken: June 2010
I know, it doesn’t look like much. Just a simple picture of water with a bird flitting by in one corner and a buch of islands on the horizon.
Look a bit closer at those islands, though.
See how only the one on the far right is actually touching the water?
The rest are a mirage, appearing to float in midair. They’re not actually where they look to be.
Mirages are commonly associated with deserts, but they can occur anywhere there is flat enough surfaces and a view to the horizon. What is happening is that the light that is the sight of those islands which would normally be hidden below the horizon is bouncing off the smooth surface of the lake. This extra bounce makes the islands visible much further than they should be, though it does shift the sight above where it should be, placing them floating in the air. And actually, they aren’t even islands. They’re the distant coastline, but only the top of the trees are being caught by the mirage. The rest of the trees are still hidden out of sight.
It’s a simple optical illusion, and fairly simple once you know how it works. You can easily see why it fooled so many, though, especially desert travelers desperate for a city or an oasis despairing as the one they see far away that fades away as they get closer and the angles of light change.
The floating island Fata Morgana mirage was a familiar sight to me. The view of Saginaw Bay from my mother’s cottage would do that to Big and Little Charity Island out in the middle of the bay.
You said that the light bounces off the surface of the lake. That would be reflection. Really the mirage is refraction. The lake cools the air immediately above the water. If you stand above the cool air, in the warm air of summer, the light bends downward as it passes into the lower, cooler, denser air. That bend lets the light pass over the horizon. My mother’s cottage sits 10 feet above the water line, so it is above the lake-cooled air. The Charity Islands were not over the horizon, but the mirage made them appear to float above the water line. I don’t know why the mirage cuts off the bottom part of the image; maybe I should do the math.
Hmm, your blog would benefit from a “Preview” button, so that I could check whether I typed the HTML link correctly.