The mystery of a mirage
One day a few years ago, in the calm and windless Cuxhaven in the North Sea, Germany, a boy playing in the street ran home and excitedly said to his mother: "Mom, there is an island in the sky!" Mom couldn't help but laugh when she heard this, and when she looked out the window, the smile on her face suddenly disappeared, because right in front of her eyes, the nearshore Haigulan Island hung upside down in the air. The red rock cliffs along the island are never mistaken, and the sand dunes and other details on the shore are clearly visible. The island was like a pair of giant hands hanging upside down in the sky, and it seemed that it could crash at any moment. Of course, Haigulan Island did not fall, it was a mirage. In the evening, the illusion in the air disappeared, and the child's fear was dispelled.
The illusion of Haguland Island, which occasionally appeared over Cuxhaven, was just one of the most astonishing atmospheric visions. The Arctic region also has this illusion, which has fooled human beings for nearly a hundred years. In 1818, the Scottish explorer Sir John Ross set out from England to the North Pole in search of the unclear "Northwest Passage", said to be a waterway connecting the Atlantic and Pacific Oceans along the north coast of North America. Ross entered unfamiliar waters north of Baffin Island in Canada. One morning, he saw a mountain in front of him on the deck blocking the way, thinking it was a dead end, so he turned the bow of the ship and sailed back, reporting that there was no northwest channel at all.
About 100 years later, the American Arctic explorer Perry also said that the Arctic had a large mountain range that was not drawn on the map. He said, "We saw those big mountains, called them the Krakolan Mountains."
This mysterious mountain range in the Arctic attracted the interest of the world at that time. What else is behind the mountains? Where do the mountains really lie? Will there be mineral deposits or yellow gold in the mountains? Are there any unknown tribal dwellers there? Many adventurers and explorers have traveled to the North Pole, but no one can find the mountains. Finally, the American Museum of New York City donated $300,000 and sent a scientific expedition into the district. McMillan, the head of the expedition, became the headliner in newspapers around the world at the time.
However, where the mountains are seen in Piri, the only thing McMillan sees is a patch of ice and snow. Piri said there were deep and wide waterways, and That Meeran had only encountered large chunks of ice floes that threatened his ship. Later, The Krakolan Mountains did appear, but strangely enough, the locations where these mountains were located were about 200 miles west of the place Piri had said.
McMillan sailed between ice floes, stopped the ship and dropped anchor when it was too late to move forward, and led a carefully selected group of people on foot on the ice. But as they marched toward the mountain, the mountain retreated, and they stopped, and the mountain stopped retreating. They went forward again, and the mountain retreated. Those icy peaks and snow seemed to beckon to them in the Arctic sun, and the dark valleys seemed likely to be rich in mineral deposits.
They bravely marched forward, and finally entered a trough surrounded by mountains on three sides, and success was in sight. But when the sun sets below the horizon, the surrounding mountains and hills disappear like a trick. They were so frightened that they could only quietly look at the real environment. They were on a vast expanse of ice, surrounded by ice, as far as the eye could see. There are no hills in front of you, and there are no big mountains. Macmillan and his party stood in the pale green shimmer of dusk in the Arctic, and nature gave them a big deception.
Mirages are light hallucinations produced under special atmospheric conditions. When light rays pass through contiguous gas layers at different temperatures (i.e., different densities), refraction occurs, resulting in a mirage. For example, suppose there is a desert where the sun heats up the sand and the air in the lowest layer above the sand also heats up. Above this thin layer of hot air, there are many layers of cooler air. Because hot air is denser than cold air, it is easier for light to pass through hot air than through cold air. When light passes through the boundaries of gas layers of different densities, its direction changes, causing the light to refract.
Suppose a man stands on a dune somewhere in the desert and watches the view, and there is a palm bush on a dune a few hundred yards from him, and between the two dunes is a layer of hot sand scorching air. In this case, although there was only one palm bush there, the man would see two palm bushes. One is the normal image, where light travels in a straight line in the air. The other is an inverted image, and underneath the first image, it is formed when light rays are refracted into the person's eyes. These rays of light shine obliquely from the palm tree into the layer of hot air that covers the desert, and then refract upwards, from below into the man's eyes, like a mirror on the desert, and from the mirror you can see the reflection of the palm tree. At the same time, the light from the sky was also refracted by the layer of hot air that shook, making people feel that it was a piece of water, and there were two palm trees in the water, really upright and fake upside down.
The "waterholes" we sometimes see on highways or other blazing planes in summer are also small mirage illusions. They're patches of sky that are refracted by scorching air on the hot plane. There are many stories of people who get lost in the desert and are often tormented mad by this mirage. The mirage is neither an illusion nor an illusion, but a refraction of a clear sky. The Arabs call them "Devil's Lake." Desert air can also create mirages, making distant oases, towns, or distant places appear to be nearby, adding a lot of material to the nomadic legends.
The deserts of southwestern North America are also known for mirage illusions. In Kochis County, Arizona, there is a 10-mile lake along the railroad line. In both winter and summer, you can see that there is water in the lake, but in fact the lake is dry in the summer, and there is no water in the lake. In the summer, the light of the sky is refracted back by the hot air on the dry bottom of the lake, creating the illusion of the lake. Local residents said there had been a tragic incident in which a plane pilot had seen the lake in the winter, and once in the summer, he wanted to lower the seaplane on the lake. Just as he began to land, the illusion suddenly disappeared. He had to make an emergency landing, and as a result, the plane crashed on the lakebed, and he was also seriously injured and killed.
If the boundary between the two layers of air is uneven, the refractive image will often be deformed. The American explorer Andrews once saw a strange beast shaped like a giant swan wading in a lake in the Gobi Desert. From hundreds of miles away, they look like behemoths from another world, their slender legs almost 15 feet long. Andrews immediately called the expedition's painter to paint these unusual beasts. He himself crept toward the lake. The closer he got, the smaller the lake shrunk, and the beast changed shape. Fat giant swans turn into slender antelopes, serenely looking for grass to eat in the desert. Hot air once produced the illusion of water, and due to the unevenness of the hot air layer, the shape of the animal became strange.