The great power of lightning has been depicted in many legends. In Greek and Roman mythology, the chief of all the gods has the power of lightning bolt. However, its nature has been a mystery until about 200 years ago. Benjamin Franklin made an experiment to investigate about lightning. In a stormy night, he flew a kite fitted with a metal rod to attract electricity. It was his assumption that lightning and electricity were the same. He had a key attached middle way to give a signal that it conducted electricity. When lightning stroke the rod, it created a spark on the key which means that it conducted electricity. This experiment was converted to the development of lightning rods that attract lightning readily during storms to prevent damage to structures. The electricity is safely conducted to the ground.
Many scientists have already tried to analyze how lightning comes into being. Thunderclouds are created by the accumulation of water vapor at heights of about 15000 m. The water vapor in the clouds is carried upward, is condensed, and is cooled below its freezing point but does not freeze immediately until it has a seed or nucleus, to form upon. And as a result it becomes supercooled. Once ice starts to form, the slow-moving ions serve as nuclei and ice precipitation falls. By the time it reaches the cloud bottom, cold downdraft is released and vain precipitation occurs. Using analysis and interpretation, scientists theorized that the friction caused by the water droplets falling through the cloud and the updraft of air currents created electrical charges on the falling droplets. Also, the water droplets are broken up. One theory suggests that upon breaking up, some of the droplets go back up and become positively charged. The ones that do fell down become increasingly negative. With repetition of this cycle, the potential difference of 100 million volts could be possible. When the potential difference is great enough, lightning occurs.
Posted 2011-01-29 and updated on Jun 08, 2011 1:59am by crisd