"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