Samplings

> When 1975 was rung in last week at Britain's old Royal Greenwich Observatory, which is located on the meridian where the earth's time zones begin, it arrived precisely one second late. For official timekeepers everywhere, including the National Bureau of Standards in the U.S., the delay was significant. The earth's rotation (which forms the basis of time units--hours, minutes, seconds) is gradually slowing down--largely because of tidal friction. For that reason, the timekeepers decided a few years ago to make an occasional correction by inserting a so-called leap second. In that way, the accurate atomic clocks that they rely on to keep the exact time do not get ahead of the less dependable earth. Since leap seconds were introduced in 1972, four have been added, and even more can be expected in the future as the earth continues its gradual slowdown.

> Since last fall, many parts of the world have reported unusually spectacular sunsets that have turned the sky into brilliant displays of red, orange and yellow. Now two atmospheric scientists at NASA'S Langley Research Center think that they have found the cause of the heavenly pyrotechnics. Writing in Applied Optics, Physicists Michael McCormick and William Fuller Jr. report that their surveys of the stratosphere with laser beams have revealed two new layers of dust at altitudes of 10 and 12.5 miles. That extra dust would enhance a well-known phenomenon: when the sun is low in the sky, its rays travel through more of the atmosphere and thus encounter more dust particles. The particles, in turn, tend to scatter the blue (or shorter) wave lengths of the spectrum more than the red, thereby causing the sky to redden at sunset or sunrise. McCormick and Fuller say that the probable source of the new dust is the frequently erupting Volcan de Fuego in Guatemala.

> Women in the sciences have long complained justifiably of a "skirt differential." That is, they have been paid less than men even when they have held comparable jobs. Now that differential may be changing in the women's favor. In a recent survey, the American Chemical Society found that newly graduated women chemists and chemical engineers are being paid on average 5% more than male graduates. A decade ago, women entering chemistry were earning only 86% as much as their male counterparts. The society says that the turnabout is probably the result of more intensive bidding by employers for women chemists to make up for "years of unequal employment practices."

This file is automatically generated by a robot program, so viewer discretion is required.