Word: crystallic
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...make molecular structures visible. Stroke had been experimenting since 1963 with new ways to utilize holography. But it was not until about a year ago that he and his colleagues-Maurice Halioua, Venugopal Srinivasan and Raghupathy Sarma-hit upon their potentially revolutionary process. Explains Stroke: "We realized that a crystal, in which the atoms are arranged in a repeating array, can be made to produce a sort of hologram, a three-dimensional display of data. What we've figured out is a way of viewing...
...team first crystallizes the molecule to be studied. The crystal is then examined by standard X-ray diffraction; the X rays that pass through the crystal and bounce off the atoms are used to make a pattern of dots that is recorded by an electronic counter. The diffraction pattern is then processed by computers to determine the relative value of each of its spots. Finally, the spots are printed on a photographic plate, which becomes a hologram of one of the crystal's planes...
...lens, which spreads it to cover the entire plate, through the plate itself and then through another lens, which acts as an optical computer and converts the spots into a coherent picture (see diagram). The result is an image showing the arrangement of atoms in one plane of the crystal. This image can be combined with images from other sections to give a three-dimensional view of the crystal's entire atomic structure. Says Stroke: "In the past, all we have been able to produce is a score. Now we can produce real music...
...symphony and show the entire structure of any molecule. But the results thus far are promising. Stroke's pilot study, involving a substance called magnesium bromide tetrahydrofuran, clearly reveals the precise arrangement of the molecule's magnesium, oxygen and carbon atoms in one plane of the crystal. It is more of the molecule than science has yet been able...
...slay herself by refusing to eat whilst the balance of her mind was disturbed." Neither statement could satisfy those who knew Simone Weil as a philosopher, teacher, factory worker, soldier, writer and friend. Her mind was not a scale to be tipped between sanity and insanity but a fixed crystal that gathered every crucial political and spiritual crisis of her time into a point of devouring intensity. She shattered at the age of 34 attempting that most difficult of 20th century feats-living in the service of an absentee God. For her sufferings and self-denials, Weil has been canonized...