What associations do you have when hear the word “Mirage”? Usually, you see a weary traveler who wanders on the hot sand and scorching Sun in search of water. A few hours he dies of thirst, but suddenly sees on the horizon an oasis. He runs to him, she is getting closer and closer. This continues until, until he jumps into the air, preparing to swim in fresh water, but again lands on the sand. You might think that the traveler’s hallucinating, but mirages are most that on there is a natural optical illusion. In cartoons, a Mirage often draw as a lush, green oasis that lies in the shadow of swaying palms, but most likely it looks like a normal pool of water.
How mirages are formed?
Let’s start with the fact that the mirages have no relationship to the water. Actually the thing is, as the light passes through the air. Normally, light waves from the sun pass right through the atmosphere to your eye. But light travels at different speeds through hot and cold air. Mirages occur when the ground is very hot and the air is cool. The hot ground heats the layer of air directly above the ground. When light passes through the cold air and into the layer of hot air it is refracted (bent).
A layer of very warm air near the Ground refracts the light from the sky nearly into a U-shaped bend. Our brain thinks that light travels in a straight line. Our brain does not perceive the distorted image as the light from the sky. Instead, our brain thinks that the light must come from something on the ground. You can see in the image above, what’s going on in order to appear a Mirage. “Twisted light from heaven” is refracted when it passes from colder air into hotter air and back to your eye. Our brain plays with us a cruel joke, suggesting that refracted light follows a straight path. Because of this, we follow the light back to the source, which, apparently, is the ground. Combining all this together, the refracted light from heaven is interpreted as a direct, allowing us to see the image of heaven on earth.
That’s why many mirages seem to be blue water. We think we’ve stumbled upon an oasis, when in fact we see the shimmering blue sky. Since our brain does not recognize heaven as being on earth, we imagine that it is shining blue water.
Where can you see the Mirage?
No need to go into the desert to see a Mirage: they are very common on roads, runways of airports, and even on the hot sand on the beach. Mirages can be found everywhere, where the earth can absorb a lot of heat. The most spectacular mirages occur on a wide expanse of flat Land, as too many hills, dips or bumps will not allow the refracted light to reach your eyes.