“发现”号航天飞机去年9月发射前有三个简单的发射箱,其中包含有几十个小的棱柱形空室。在起飞时里面除了几滴清洁的液体外什么也没有。然而当飞船返回时,每个小室的液体中都浮着一个由纯蛋白质构成的完美的晶体,其大小不超过一颗盐粒。搞清每个微粒的分子结构或许是寻找新的抗病武器的关键。生物学家们依靠这样的有机晶体来研究酶、激素和病毒的结构单元,但在地球上制造蛋白晶体总是困难的。在重力影响下,一个生长中的晶体从周围的液体中吸取粒子,产生微小的紊流波,这将把分子搞乱,即使它们在聚集过程中也是这样。进而,当晶体大到 The Space Shuttle Discovery had three simple launch bins containing dozens of small prismatic chambers before launching in September last year. There was nothing but a few drops of clean liquid on takeoff. However, when the spacecraft returns, the perfect crystal of pure protein floats in the liquid in each cell, and its size does not exceed one grain of salt. Finding the molecular structure of each particle may be the key to finding a new disease-resistant weapon. Biologists rely on such organic crystals to study the structural elements of enzymes, hormones and viruses, but it is always difficult to make protein crystals on Earth. Under the influence of gravity, a growing crystal draws particles from the surrounding liquid, creating tiny turbulent waves that mess up the molecules, even as they accumulate. Further, when the crystal is large