10 mysteries of the world, that science is finally revealed
From 1940 until recently, Racetrack Playa, dry lake with a flat bottom, located in Death Valley in California, it was a place where there was the phenomenon of "moving the stones." Above this mystery to puzzle many people. Years or even decades, some force seemed to move rocks on the surface of the earth, and they left behind a long furrow. These "moving stones" weighed about 300 kg and kazhdyy.Nikto never seen how they move. Experts see only the final result of this phenomenon, and no more. In 2011, a group of American researchers has decided to deal with this phenomenon. They established a special chamber and a weather station to measure wind gusts. They also set the GPS-tracking system and began zhdat.Moglo pass ten or more years before anything happened, but the researchers got lucky and it happened in December 2013th goda.
Due to the rain and snow on the dried bottom of the accumulated layer of water is about 7 cm. At night the frost hit, and there were small groups of ice floes. Weak wind, whose speed was about 15 km / h, was enough to make the ice began to move and push the boulders at the bottom of lakes and boulders left furrows in the dirt. These grooves become visible only a few months later, when the bottom of the lake again vysohlo.Glyby move only when the conditions - perfect. For their movement does not need too much (but not too small) of water, wind and sun. "Perhaps, the tourists have already seen this phenomenon, but simply did not understand it. Really hard to see that the lump moves if clumps around her move too, "- said the researcher Jim Norris.2. As giraffes can stand on such thin legs?
Weight giraffe can reach a ton. But for this size giraffes incredibly thin leg bones. Nevertheless, these bones are not lomayutsya.Chtoby find out why, researchers from the Royal Veterinary College tested the limb bones of giraffes, donated them to zoos of the European Union. These were certainly giraffes died a natural death. The researchers found bones in a special frame, and then secure them to the weight of 250 kg to simulate the weight of the animal. Each bone was stable, and no signs of fracture was observed. Then it turned out that the bone can carry even greater ves.
The reason was a fibrous tissue, which is in particular a groove along the entire length of bone giraffe. Leg bones giraffe bit like metatarsal bones in the human foot. However, the giraffe, these bones are much longer. By itself, fibrous ligament in a bone of a giraffe does not create any effort. It provides only a passive support, because sufficiently elastic, although it is not the muscle tissue. This, in turn, reduces the fatigue of the animal, as it does not need too intense use their own muscles to move its weight. Also, fibrous tissue protects the foot giraffe, and prevents perelomy.3. Singing sand dunes In the world there are 35 sand dunes, a loud sound, which is a bit like a low sound cello. Sound can last 15 minutes, and can be heard at a distance of 10 km. Some dunes "sing" only occasionally, some - every day. This occurs when the surface of the grains of sand dunes begin to slide vniz.Snachala researchers thought that the cause of sound - vibrations in the sand layers that are close to the surface of the dunes. But then it was discovered that the sound of the dunes, you can recreate in the laboratory, allowing a sand slide down the incline. This proved that "singing" sand dunes instead. Sound is produced by the vibration of the sand grains themselves when they slipped vniz.Potom cascade, researchers have tried to find out why some dunes play several notes simultaneously. To do this, they studied the sand dunes with two, one of which is located in the eastern Oman, and another - in southwest Marokko.Marokkansky sand produces a sound with a frequency of about 105 Hz, which was similar to the G-sharp. Sand from Oman can produce a wide range of sounds, which included nine notes of the F-sharp to D. Sound frequencies were in the range of 90 to 150 Gts.Bylo found that the height of music depends on the size of grains of sand. Grits from Morocco were about the size of 150-170 microns, and always sounded like a G sharp. Grits from Oman were the size from 150 to 310 microns, because of their sound range consisted of nine notes. When the researchers sorted the sands of Oman in size, they began to sound at a single frequency, and reproduces only one motion notu.Skorost sand - is also an important factor. When the grains are about the same size, they are moved approximately the same distance at the same speed. If the grains differ in size, they are moved at different speeds, thereby can reproduce a wider range not.4. Pigeon Bermuda treugolnik
This puzzle appeared in the 60s, when a professor at Cornell University studied the remarkable ability of pigeons find their way home from the places where they were not previously. He released the pigeons from various locations throughout the state of New York. All pigeons returned home, except one, which was released at Jersey Hill. Doves released there almost every time teryalis.13 August 1969, the year these pigeons have finally found the way home from Jersey Hill, but it seemed they were disoriented and flew around quite chaotic. The professor was unable to explain why it proizoshlo.Doktor Jonathan Hagstrum from the US Geological Survey believes that he might have been able to reveal this mystery, although his theory is quite controversial.
"Birds carry out their navigation using a compass and a map. Compass, as a rule, is the position of the Sun or the Earth's magnetic field. A sound as they use the card. And all this tells them how far they are from home ». Blockquote> Hagstrum believes that pigeons use infrasound, ie very low frequency sound that the human ear can not hear. Birds may use infrasound (which may be generated, for example, ocean waves or small vibrations on the surface of the Earth) as a drive radiomayaka.Kogda birds lose in Jersey Hill, the air temperature and the wind made infrasound signal spread high in the atmosphere, and the dove We heard him about the surface of the earth. However, August 13, 1969, the year the temperature and wind conditions were excellent. Thus, the pigeons were able to hear infrasound, and found their way domoy.5. The unique single origin Australian vulkana
In Australia, there is only one volcanic area that extends for 500 km, from Melbourne to Mount Gambier. Over the past four million years there was observed about 400 volcanic events, and the last eruption was about 5000 years ago. The scientists could not figure out what caused all these eruptions in the region of the world, which is not observed almost no other volcanic aktivnosti.Seychas researchers uncovered this secret. Most of the volcanoes on the planet are located at the edges of tectonic plates that are constantly moving a short distance (around a few centimeters per year) over the surface of the Earth's mantle. But in Australia, changes in the thickness of the continent led to the unique conditions in which heat comes from the mantle to the surface. In conjunction with the drift of Australia to the north (it takes about 7 cm per year), this led to the fact that on the continent there was a hot spot, creating magma. "There are still about 50 of the same isolated volcanic regions around the world, and the emergence of some of them we currently can not explain, "- said Rhodri Davies of the National University of Avstralii.6. Fish living in polluted vode
From 1940 to 1970 years, the plant dumped waste containing polychlorinated biphenyls (PCBs), right in the harbor of New Bedford, Massachusetts. In the end, the Agency for Environmental Protection announced the harbor zone of ecological disaster, because the level of PCBs there repeatedly exceeded all permissible normy.A more the harbor is home to a biological puzzle, which, according to the researchers, is finally on razgadana.Nesmotrya serious toxic pollution, fish called the Atlantic fundulyus continues to live and thrive in the New Bedford harbor. These fish are in the harbor throughout his life. Normally, when the fish digests PCBs, toxins contained in this material, under the action of the metabolism of fish are more opasnee.No fundulyus able to genetically adapt to the poison, and as a result of the toxins in his body do not occur. Fish is fully adapted to the pollution, but some scientists believe that these genetic changes can make fundulyusa more susceptible to attack from other chemicals. In addition, it is possible that the fish simply can not live in a normal, clean water, when the harbor finally cleared of zagryazneniya.7. How did the "underwater wave"
Underwater wave, also called "internal waves", located under the surface of the ocean and are hidden from our eyes. They raise the surface of the ocean just a few centimeters, so they are extremely difficult to detect, and can only help here sputniki.Samye large internal waves arise in Luzon Strait, between the Philippines and Taiwan. They can climb the 170 meters and travel long distances, moving for a moment only a few santimetrov.Spetsialisty believe that we need to understand how these waves arise, as they can be an important factor in global climate change. The water is cold and the internal waves salty. It is mixed with water surface waves, warmer and not as salty. Internal waves are transferred through the ocean of large amounts of salt, heat and nutrients. With their help, the heat is transferred from the surface of the ocean to its glubinam.Issledovateli long wanted to understand how there are huge internal waves in the Strait of Luzon. They are difficult to see in the ocean, but the devices can detect the difference in density between the internal wave and the water that surrounds it. The experts decided to start the process to simulate the appearance of waves in the 15-meter vessel. Get internal waves managed by submitting a pressurized stream of cold water for two "ridges" which are at the bottom of the tank. So it seems that the huge internal waves arise because of the chain of mountain ranges located at the bottom of proliva.8. Why do zebras poloski
There are many theories about why the zebra - striped. Some believe that the stripes act as camouflage, or is this a way to confuse predators. Others believe that the zebra stripes to help regulate their body temperature, or choose their paru.Uchёnye University of California decided to find the answer to this question. They learned where they live all species (and subspecies) zebras, horses and donkeys. They have collected a lot of information about color, size and location of zebra stripes on their bodies. They then mapped the habitat of tsetse flies, horse flies and deer flies. Then they took into account several variables, and finally conducted a statistical analysis. And they have the answer.
"I was impressed with our results. Again and again the stripes on the body of animals observed in those regions of the world where it has been most of the problems associated with biting flies ». Blockquote> Zebras suffer more from biting flies, as their hair shorter than that of the same horses, for example . Bloodsucking insects can carry deadly diseases, so that zebras need to avoid this risk by any available sposobom.Drugie scientists from the University in Sweden have found that flies avoided riding a zebra because she strips - right width. If the strips are wider, the zebra not be protected. The study found that the flies are most attracted to the black surface is less attracted to the white surface and the least attractive to them has striped poverhnost.9. Mass extinction of 90% of species Zemli
252 million years ago, about 90% of animal species on the planet was destroyed. This period is also known as "The Great Extinction" and considered to be the mass extinction on Earth. It's like an ancient mystery, in which the suspects were very different - from volcanoes to asteroids. But it turned out that the killer may be considered only in mikroskop.Po version of researchers from MIT, the culprit was the extinction of one-celled organisms called Methanosarcina, which consumes carbon compounds to form methane. This microbe exists today in landfills, in oil wells and in the intestines of cows. In the Permian period, scientists believe, Methanosarcina survived the genetic transformation of bacteria, allowing Methanosarcina acetate handle. Once this happened, the microbe was able to eat a bunch of organic substances containing acetate, and are at the bottom of okeana.Populyatsiya microbes literally exploded, spewing into the atmosphere huge amounts of methane and oxides of the ocean. Most of the plants and animals on land were killed, along with fish and shellfish in okeane.No to breed in such a wild pace, the microbes would require nickel. After analyzing the sediments, the researchers speculated that volcanoes are acting in what is now Siberia spewed large amounts of nickel required mikrobam.10. The origin of the oceans Zemli
Water covers about 70% of the surface of our planet. Previously, scientists thought that at the time the Earth's water in it was not, and its surface was melted due to collisions with the various celestial bodies. It was believed that there was water on the planet much later, as a result of collisions with asteroids and wet kometami.Odnako new study shows that the water was on the surface of the earth at the stage of its formation. The same may be true for other planets sistemy.Chtoby determine when the water came to Earth, the researchers compared the two groups of meteorites. The first group are carbonaceous chondrites, the oldest meteorites ever found. They appeared around the same time as our sun, even before any planets in the solar sistemy.Vtoraya group - a meteorite, who arrived from Vesta, a large asteroid that was formed in the same period as the Earth, that is, approximately 14 million years after the birth of the solar system.This meteorites two types have the same chemical composition and contain a lot of water. For this reason, researchers believe that the Earth was formed on the surface of the water, carbonaceous chondrites unit tunes to about 4, 6 billion years ago.
via factroom.ru
