Wednesday, June 29, 2011
Ghost Cities Explained, UFOs Too?
Few people realize that our atmosphere is capable of creating some rather bizarre phenomena. In fact, it is capable of creating one of the most confusing sights of all – a mirage.
A mirage occurs when light, passing through air layers of different densities, refracts (or bends) towards the denser air. Usually we see a mirage as the sky reflecting on the ground. However, another type of mirage can cause an image of something on the ground to appear in the sky.
This particular type of mirage, known as a superior mirage, forms in a condition called temperature inversion. This is when the air in one layer of atmosphere is colder than the layer directly above it. When this occurs, light rays refract toward the colder, denser air (downward). This refraction causes the image of an object or light source to appear above its actual position. The rate, at which the temperature rises in relation to height, changes the way those light rays travel from that object to our eyes.
This effect can make the image appear in the sky even when it is well below the horizon. These images can also seem distorted and appear projected far above their actual position. They can appear taller, shorter, larger, smaller or any combination of these. Images can even appear inverted or multiplied.
The most common form of a superior mirage is a looming mirage. These have usually appeared over large bodies of water when the liquid is colder than the air above. The same thing can occur in deserts, where the ground (especially during the spring and fall) can cool down much more rapidly than the air. Because of this illusion, the object will often appear to be “floating” in the sky. If there is a great deal of refraction occurring, then the object(s) can appear very high in the sky.
This may be the cause of such sightings as “flying ghost ships” and UFOs. Dr. Ivan Sanderson, who is something of an authority on UFOs as they relate to water, stated in his book, Invisible Residents, that “by actual account, over 50 percent of all so-called ‘sightings’ of UFOs have occurred over, coming from, going away over, plunging into or coming out of water.”
The atmospheric inversion necessary for this phenomenon to appear most often occurs during the night and can last for long periods. It is at night that earthbound lights can become part of a superior mirage. Headlights, refracted into the sky, can appear larger, faster and seemingly capable of impossible aeronautical maneuvers.
Many individuals who have claimed to see UFOs say they can travel at high speeds and suddenly make a ninety-degree turn. It is possible that the headlights of a car, traveling down a road, can become part of a mirage, which projects them high into the sky (under the proper circumstances). The lights on this vehicle could appear to be a high velocity UFO making an amazing ninety-degree turn when it’s simply turning a corner. Because of the exaggeration of the mirage, these two small lights can appear larger, faster, or even become a “squadron” of lights.
In the book Rainbows, Haloes and Glories, Robert Greenler recounted an instance of a superior mirage appearing over Lake Michigan. The people of Grand Haven, Michigan saw city lights and a flashing red beacon floating over the lake. The nearest city, however, was Milwaukee, Wisconsin, which lies seventy-five miles away – well below the horizon. And the looming mirage of what might have been Bristol England was seen regularly for several years from a vantage point in Alaska.
This is a strong, scientific case for some sightings but it hardly explains them all. There are sightings all over the world in many different types of atmospheric conditions. They cannot all be mirages. Some UFO sightings still defy explanation. Those sightings will continue to fuel the debate, challenge science, and spark our curiosity.