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The discovery of planets around distant stars has become like space-shuttle launches—newsworthy but just barely. With some 50 extrasolar planets under their belt, astronomers have to announce something really strange to get anyone’s attention.Last week they did just that. Standing in front of colleagues and reporters at the American Astronomical Society’s semiannual meeting in San Diego, the world’s premier planet-hunting team—astronomer Geoffrey Marcy of the University of California, Berkeley, and his colleagues—presented not one but two remarkable finds. The first is a pair of planets, each about the mass of Jupiter, that whirl around their home star 15 light years from Earth in perfect lockstep. One takes 30 days to complete an orbit, the other exactly twice as long. Nobody has ever seen such a configuration. But the second discovery is far stranger—a solar system 123 light years away in the constellation Serpens, that harbors one "ordinary" planet and another so huge—17 times as massive as Jupiter— that nobody can quite figure out what it can be. "It is," says Marcy, "a bit frightening."What’s frightening is that these discoveries make it clear how little astronomers know about planets, and they add to the dawning realization that our solar system—and by implication Planet Earth—may be a cosmic oddball. For years theorists figured that other stars would have planets more or less like the ones going around the sun. But starting with the 1995 discovery of the first extrasolar planet—a gassy monster like Jupiter but orbiting seven times as close to its star as Mercury orbits around our sun—each new find has seemed stranger than the last. Searchers have found more "hot Jupiters" like that first discovery. These include huge planets that career around their stars not in circular orbits but in elongated ones; their gravity would send any Earthlike neighbors flying off into space. Says Princeton astronomer Scott Tremaine: "Not a single prediction for what we’d find in other systems has turned out to be correct."Last week’s giant was the most unexpected discovery yet. Conventional theory suggests that it must have formed like a star, from a collapsing cloud of interstellar gas. Its smaller companion, only seven times Jupiter’s mass, is almost certainly a planet, formed by the buildup of gas and dust left over from a star’s formation. Yet the fact that these two orbs are so close together suggests to some theorists that they must have formed together—so maybe the bigger one is a planet after all.Or maybe astronomers will have to rethink their definition of "planet." Just because we put heavenly objects into categories doesn’t mean the distinctions are necessarily valid. And as Tremaine puts it, "When your classification schemes start breaking down, you know you’re learning something exciting. This is wonderful stuff.\ Why are the two finds by Geoffrey Marcy and his colleagues remarkable（）
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Design of all the new tools and implements is based on careful experiments with electronic instruments. First, a human "guinea pig" is tested using a (31) tool. Measurements are taken (32) the amount of work done, and the buildup of heat in the body. (33) joints and stretched muscles cannot (34) as well, it has been found, (35) joints and muscles in their (36) positions. The same person is then tested again, using a tool designed according to the suggestions made by Dr. Tichauer. All these tests have shown the great (37) of the new designs over the old.One of the electronic instruments used by Dr. Tichauer, the myograph (肌动描记器), (38) visible through electrical signals the work done by human muscle. Another machine (39) any dangerous features of tools, thus proving information upon (40) to base a new design. One (41) of tests made with this machine is that a tripod stepladder is more (42) and safer to use than one with four legs.This work has (43) the attention of efficiency experts and time-and-motion-study engineer, but its value goes far (44) that. Dr. Tichauer’s first (45) is for the health of the tool user. With the (46) use of the same tool all day long on (47) lines and in other jobs, even light (48) work can put a heavy stress on one small area of the body. In time, such stress can cause a disabling disease. (49) , muscle fatigue is a serious safety (50) . （38）（）
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The destruction of our natural resources and contamination of our food supply continue to occur, largely because of the extreme difficulty in affixing legal responsibility on those who continue to treat our environment with reckless abandon. Attempts to prevent pollution by legislation, economic incentives and friendly persuasion have been met by lawsuits, personal and industrial denial and long delays—not only in accepting responsibility, but more importantly, in doing something about it.It seems that only when government decides it can afford tax incentives or production sacrifices is there any initiative for change. Where is industry’s and our recognition that protecting mankind’s great treasure is the single most important responsibilityIf ever there will be time for environmental health professionals to come to the frontlines and provide leadership to solve environmental problems, that time is now. We are being asked, and, in fact, the public is demanding that we take positive action. It is our responsibility as professionals in environmental health to make the difference. Yes, the ecologists, the environmental activists and the conservationists serve to communicate, stimulate thinking and promote behavioral change. However, it is those of us who are paid to make the decisions to develop, improve and enforce environmental standards, ! submit, who must lead the charge.We must recognize that environmental health issues do not stop at city limits, county lines, state or even federal boundaries. We can no longer afford to be tunnel-visioned in our approach. We must visualize issues from every perspective to make the objective decisions. We must express our views clearly to prevent media distortion and public confusion.I believe we have a three-part mission fur the present. First, we must continue to press for improvements in the quality of life that people can make for themselves. Second, we must investigate and understand the link between environment and health. Third, we must be able to communicate technical information in a form that citizens can understand. If we can accomplish these three goals in this decade, maybe we can finally stop environmental degradation, and not merely hold it back. We will then be able to spend pollution dollars truly on prevention rather than on bandages. The word "tunnel-visioned" (Line 2, Para. 4) most probably means（）
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