Tuesday, November 26, 2019
Aurorae Borealis essays
Aurorae Borealis essays The Northern Lights and Kristian Birkeland The northern lights have inspired awe and reverence in people all throughout the northern latitudes. At their most impressive, they form an immense halo of pulsating light around the pole, stretching hundreds of kilometers out into space. People in the 18th century were unsure what to make of these mysterious lights. The Lapps saw the lights as messengers of God which might strike down anyone foolish enough to provoke them. In Scandinavian folklore, the lights are reflections from icebergs, the wings of migrating geese, or from shoals or herring swimming close to the surface of the sea. It was Galileo who first dubbed the termboreal aurora? to describe the northern lights, after Aurora, the Roman goddess of dawn. Though the name stuck, it is misleading because aurora seen in southern latitudes glow pinkish-red. True aurora is green and white. Norwegian scientist Kristian Birkeland (1867-1917) had long been fascinated with the strange and hypnotizing lights. In 1899 he and several others made a journey to a mountaintop in Norway, during which they experienced frostbite, week-long blizzards and months of sunless winter desolation. There he verified that the aurora was not lights bouncing off icebergs but rather an electrical phenomenon triggered by solar activity. He hypothesized that they arose from the interaction between electrically-charged particles emanating from the Sun and the Earth's magnetic field. Birkeland's claims were strengthened by a more extensive survey in the winter of 1902 that involved four observation stations set up around the Artic Circle in Russia, Iceland and Norway. Despite the evidence he had, his theories failed to gain widespread acceptance until essentially confirmed by satellite evidence in the 1960's. Birkeland was eccentric and brilliant. An avid Egyptophile, he often wore a fez and red leather slippers with pointed toes. He was a hig...
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