Word: sun
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Dates: during 1980-1989
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Schwabe had been searching for the hypothetical planet Vulcan, supposedly the closest one to the sun, hoping to spot it in silhouette as it moved across the solar disk. In the process, he observed and kept meticulous records of sunspots over a 17-year period. Finally, in 1843, he recognized and announced the eleven-year cyclic nature of the spots and wrote, "I may compare myself to Saul, who went to seek his father's ass and found a Kingdom...
Sunspots tend to travel in pairs or groups of opposite polarity, like the ends of horseshoe magnets poking through the solar surface. During one eleven- year cycle, as the blemishes traverse the face of the sun in an east-west direction, the leading spots of each group in the northern hemisphere will generally have positive polarity, the trailing spots negative. In the southern hemisphere, the leading spots will be negative. During the next cycle, the hemisphere polarities will reverse. On average, then, 22 years will pass between solar maximums of the same sunspot polarity. This suggests to many astronomers that...
Since the sun in myriad ways governs the very existence of all terrestrial life, the cyclic changes in the sunspot population have, ever since Schwabe, inspired speculation about their effect on solar radiation and, consequently, on the earth. Though the sun is a rather ordinary star, its vital statistics are breathtaking by earthly standards. Some 865,000 miles in diameter, it consists largely of hydrogen (72%) and helium (27%) and is 333,000 times as massive as the earth. Solar temperatures range from about 27 million degrees F* in the core, where 600 million tons of hydrogen are fused into...
Like a giant nuclear-fusion furnace in the sky, the sun radiates stupendous amounts of energy. Some of it departs in the form of speeding particles, mostly electrons and protons, that form a solar wind blowing from the sun in all directions. It is this continuously flowing wind that feeds particles into the earth's Van Allen radiation belts and distorts the terrestrial magnetic field into a teardrop shape. It also sets off the frequent minor auroral displays visible at higher latitudes...
...reported in 1976 that their carbon-14 content seemed to vary in rhythm with sunspot numbers. When sunspots were rare, as they were during the Maunder minimum, the amount of carbon 14 in the tree rings increased markedly; when they were numerous, the amount decreased. The explanation: during the sun's more active periods, its magnetic field, which ordinarily deflects some cosmic rays away from the earth, expands and becomes an even greater barrier to the rays. As a result, less carbon 14 is created in the atmosphere and less finds its way into trees...