Hack Sestak, age 11, of Delmar, N. Y.y for his questions
What causes a mirage?
These little tricksters seem to occur out of nowhere and they pop up to fool us on land and lea,, Actually they are pictures painted by sunlight and air. Since a layer of warm aid is necessary to paint the picture, we see mast of them in the summer. The most common mirage appears on the road. Some distance ahead we see, or think we see, sheets and pools of water. If a car is coming towards us, it is reflected in the mirage upsidedown. But the whole picture disappears before we get close enough to examine it.
flays of light, striking the earth., carry an image of the scenery, If this were not so we could not see. For these rays of light bring a picture of the scenery to our eyes. Sometimes, rays of light bearing a picture or image of some object are forced to bend or turn around. When this happens, the image is taken and put somewhere else. Then we do not see the real object., but a mirage picture of it in the air.
Light rays are bent when the air is uneven. This happens when there are patches of light air alongside patches of dense heavy air, This may happen around a lighted candle. The flame warms the air next to it and this warm air expands. It becomes lighter and rises in wavy currents. Light passing through these wavy currents of air is forced to bend this way and that. And the light is carrying a picture of the room towards our eyes. In the area around the flame, objects seem to wave and shimmer. This is really a junior mirage„
The mirage on the road is paused by a lager of warm air close to the pavement. This layer of warm air bends the light rays upward and changes the scenery. The image of the sky is turned upside down be that we see its reflection on the grounds What looks like a puddle of water is really a mirror image of the sky. The image of the oncoming car i s also turned around so that we see a shimmering upside down reflection on the road,
As we get nearer to the mirages it disappears for two reasons. There is not less air to fool us between us and the image. Also the angle at which we look changes. Light tends to bounce off an object at the same angle at which it strikes it. As we get nearer, the angle becomes sharper and only the long sloping rays, coming from a distance can fool us;
Sometimes without realizing its we see the mirage of a ship which has already passed out of sight over the horizon. Sometimes very rarely, we see the mirage of a ship standing upside down over the real ship. Deserts, a s we all knows are famous for tempting mirage s, though tales of desert mirages are often exaggerated. All these tricks are caused by sunlight bent by layers of warm arid cooler air.