Friday, November 13, 2009

asal mula petir masih misterius

Previously, lightning conceived as a giant spark jumps between the two masses with different electric field. But U.S. physicist shows the electric field in the theory of lightning current can not grow enough to produce lightning.


Ancient Greek legend, mentioned this earth supposedly controlled a number of gods, including Zeus, God of Thunder. He could punish anyone with the lightning that could dilecut of hand. No mercy for the victims. That legend. But apart from all that, cases of people struck by lightning was still going on today, and some have experienced it several times. And already more than four centuries of conquest Benjamin Franklin lightning with a kite that hung the key.


As is known, has been conceived as the lightning sparks a giant leap between the two masses with different electric field. The basic principle about the same with the fire jumps the spark plug. In nature around us, thunder clouds usually occur in the middle of the storm clouds grow into. So great that when lightning shot, the clouds will clear the body makes. And, as a result of the split air, sambarannya which have an average speed of 150,000 km / sec it will also cause noise blaring sounds called: geluduk, thunder, or lightning. In the rainy season like this when the clouds of this type many forms.


When the accumulation of electric charge in the cloud has been enlarged and stable, power jump (eletric discharge) who happens also to reaching other electrical bermedan mass, in this case is the earth. Connecting the 'popular', referring to Faraday's Law, none other than buildings, trees or metal poles pointy toes.


I have found no scientist has ever really explore how the occurrence of this natural phenomenon. However, they are expected to leap own electrical sparks occur, there are several steps that normally follow. First, electric charge compression on the cloud in question. Generally, it will accumulate at the top of the cloud is a negative electrical charge; in the middle is a positive electrical charge; at the bottom is a mix of negative charge with positive charge. At the bottom of this berlontaran ordinary lightning.


Large minimum electric field that allows triggering lightning is approximately 1,000,000 volts per meter. Imagine how terrible if this sparks leap about the bodies of living things!


Due to certain conditions, the earth tends to be static electricity reducer, can also come to interact. This is possible if at a certain area of electricity occurs pengonsentrasian positively charged. Was it a building or under trees. When the charge difference between the cloud base to the end of the building / tree has reached a certain limit, will become a common occurrence if the electric displacement then occurs. So physically we will see it as lightning struck the building or tree. Charge so much more will soon spread to all parts of the building / tree, and then spread to the ground and neutralized on the depth of soil that contain water.


Such conditions are certainly very dangerous for those around him. If sambarannya not too strong, the only victim suffered injuries and / or shock. But if a strong attack, the victim will die instantly because other than burning it will be 'conducting' the amount of electricity reaches thousands of volts.


Actual technological advances have allowed the ways of controlling the electric current from the sky so big it was. Namely, the lightning rod where the electric current was so great that captured a bronze or a pointy top and then flows through the 'highway' of copper wire attached to the side of the building and immediately taken to the ground water.


According to research, the lightning raid itself was always a shaded area of the clouds. Some cases show that a region once had a great lightning strikes despite clear sky above the clouds. The most extreme examples ever recorded occurred in Hereford, England. Once upon a time a powerful lightning stormed a building after this lightning traveled about five miles from the 'center'. From a distance a number of witnesses saw a sight so beautiful and terrible. (Handbook of Unusual Natural Phenomena, 1986).


More recently the theory of lightning is a refutation. According to Nature magazine website reported on November 17 last, the model established by an American physicist shows that the electric field in the theory of the lightning current can not grow enough to produce lightning, the traditional theory associated with the occurrence of lightning is thus considered a false theory .


Counts conducted by Joseph Dwyer of the Florida Institute of Technology, USA, showed that if just dependent on the electric field in the atmosphere, the magnitude of the electric field can not be sufficient to cause lightning. He said, "This means that the (relevant theory) should start from the beginning."


Dwyer primarily working in the field of high energy particle research in the space dimension, but after 2 years ago he moved in Central Florida as one of the world's most prominent cause of lightning, he has an interest terbangkit on reports of an explosion of X-rays and gamma rays giant , associated with lightning. Radiation high-energy radiation is usually only noticeable on the outside layer of air, and besides when the speed through the layers of the atmosphere decreases.


Most scientists believe, that when after an electric field is formed in the atmosphere, then the lightning will occur. Although no one has ever seen this electric field, the researchers imagine that just because they do not see the lightning strong enough.


When Dwyer made the model of the factors that produce high energy radiation and describes the formation of an electric field in a flash, she was shocked. He found the release of gamma rays and X-rays to make an electric field spreading, prevent an electric field is enlarged to cause lightning. "This is probably an important theoretical breakthrough," says Martin Uman of the University of Florida who was paying attention lightning research. He has shown that in a small volume can establish how much dose X-rays and gamma rays.


In the explosion of lightning, when the air currents rising air currents pushed down the water molecules hit each other causing electrons to produce an electrical field resulting in large increases. These electrons can eventually overcome the obstacles that arise at the time through the air, and can increase the speed, and some electron velocity near the speed of light. According to the model of Dwyer, the electrons of this high-speed particles collide with others, moments before an explosion of gamma rays or X-rays that cause the release of energy from the electric field, can shoot down more electrons, thereby reducing the electrical charge. Dwyer argues, "That really is a fundamental limit associated with electric pressure can bereksis how large the electric field." Today, the real origin of lightning remains a mystery.

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