New Map Pins Down Mysterious ‘Dark Matter’ in Space(28853)-英语教育-(68)-21英语网

　　ASTROPHYSICISTS have unveiled the first atlas of "dark matter", the strange substance that is believed to comprise most of the cosmos and presents one of the greatest puzzles in space science today. 　　Dark matter is the term for matter which cannot be detected directly, because it does not emit or reflect light or radiation - or, at least, not enough to be detected by our present sensors. But its presence can be inferred because its gravitional force deflects light from distant galaxies. 　　What exactly dark matter is remains unknown: the big bet is that it is some as-yet undiscovered elementary particle, some relic of the "Big Bang" that created the Universe around 13 billion years ago. 　　Whatever it is, there's a lot of it about. By some estimates, four-fifths of the matter in the Universe is "dark", and only a fifth is "bright", or perceptible to our technology. 　　Last year, astronomers took a major step to chart dark matter, with a map of the substance around individual galaxies and galactic clusters. 　　In a paper published online yesterday by the British journal Nature, scientists based in Europe and America have taken this endeavour another stride further with the first three-dimensional map of dark matter. 　　

(China Daily Jan. 8, 2007)

　　天体物理学家们首次绘制出了“暗物质”的三维立体图，这种神秘的物质占据了宇宙的大部分质量。一直以来，它是科学界最大的谜团之一。　　暗物质是一种人类不能直接观察到的物质，因为它既不反射也不释放光线或放射线——至少，我们现有的探测器无法观测到它。但是科学家可以通过对因受暗物质重力影响而发生扭曲的遥远星系的光线进行分析判断它的存在。　　暗物质究竟是什么目前还是一个谜。一种猜测是它是一些尚未被发现的基本粒子，约13亿年前宇宙大爆炸时产生的一些遗留物。无论暗物质是什么，我们知道我们周围都有很多这种物质。科学家们在目前的科技水平下做出的统计显示，宇宙中约五分之四物质是“暗”的，只有五分之一物质是“亮”的。　　去年，天文学家开始着手为暗物质绘图，地图上包括个体星系和银河系群星周围的物质。7日，英国杂志《自然》在网上发布的学术论文指出，欧美科学家绘制的首幅暗物质三维立体图使这一努力又前进了一步。　　　　