Word: interior
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Dates: during 1980-1989
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Most explanations of that phenomenon liken the sun to a dynamo. Mighty currents of electricity flowing in the solar interior generate magnetic-field lines that, like the earth's, tend to be oriented in a north-south direction. But because the sun, unlike the earth, is gaseous, it does not rotate uniformly: bands of gases around the equator circle the solar axis once every 27 days, compared with a 34-day rotation rate near the poles...
...that may be true, says Caltech physicist Robert Leighton, "if the sun didn't have a magnetic field, it would be as dull as most nighttime astronomers think it is." What a difference a field makes. Twisted and stretched by both the sun's rotation and its roiling interior, the magnetic lines of force orchestrate the intriguing solar cycle...
...same time, hot gases, being lighter, rise from the interior to the surface, while cooler, heavier gases descend -- a process called convection (similar to what occurs in a hot oven). As a result of these massive convection currents and the differing rates of solar rotation, the magnetic lines of force begin wrapping around the sun like ropes. The wrapping action stretches the ropes and creates magnetic fields so strong that they repel the surrounding solar gases. In effect, this makes the magnetic regions lighter than the gases, and they begin to rise. Some reach the surface and become sunspots, dark...
...refine or revise this model, scientists must learn more about the interior structure and behavior of the sun. A new tool has evolved that should help them in their quest -- helioseismology, which, simply stated, involves "listening" to the interior of the sun as it bubbles, gurgles and swirls. The entire outer third of the sun is a seething ocean of gas, constantly churned by thermal convection. And convection, says astronomer John Harvey of the National Solar Observatory at Kitt Peak, "is a very noisy process. So the sun makes noise, just as a pot of water does as it boils...
...fees were doled out to prominent Republicans and a handful of rich developers. Pierce stood idly by as his executive assistant, Deborah Gore Dean, 35, turned over contracts to firms that enlisted Washington insiders as consultants. They included Dean's close friend former Attorney General John Mitchell and former Interior Secretary James Watt...