![]() ![]() "More material and more tests are needed to understand how nature has managed to accomplish the feat."Īt the moment, however, the Koryak sample is the only known naturally occurring quasicrystal. "Now that we know that quasicrystals formed in the early solar system, we need to understand exactly how," Steinhardt said. Inside meteorites, which have been exposed to the environment of space, the ratios of oxygen atoms and their variations, called isotopes, are fixed by intense space radiation and cosmic rays.īut the interior of Earth shields elements from these rays, allowing materials inside Earth-bound rocks to mix and changing these ratios.Īn examination of the oxygen isotopes in the Russian rock indicated that it must have originated in the early solar system. 2 issue of the journal Proceedings of the National Academy of Science. The scientists reported their findings in the Jan. With the first naturally occurring quasicrystal finally found, the next step was to determine its origins.īindi led a team of researchers in analyzing the quasicrystal rock's structure, which revealed that the rock must have had an extraterrestrial birth. One of the rocks, which had been found in the Koryak Mountains in eastern Russia, was a perfect match. Then, in 2007, Luca Bindi of Italy's University of Florence offered his collection of minerals to the group for examination. In 1998, Steinhardt and his team began a systematic search for a naturally occurring quasicrystal, scanning databases of known crystals for patterns that resembled those of quasicrystals.Įach candidate sample was sliced and diced with X-ray and electron diffraction imaging techniques, Steinhardt said.įor eight years the team sought in vain. "One of the reasons for conducting a search of natural quasicrystals is to see if nature found ones that have not yet been discovered synthetically by trial and error." "At present, we have a limited menu of quasicrystals," Steinhardt said. Synthetic quasicrystals are used to strengthen steel and aluminum, or to create a Teflon-like material that is harder and nearly as slippery as the metals. The most familiar of such arrays is found on the face of a soccer ball, composed of 20 hexagonal faces with 12 pentagons interspaced. "Any symmetry thought to be forbidden is possible for quasicrystals," he told in an email. Researcher Paul Steinhardt of Princeton University describes such a bizarre arrangement as "a disharmony in space."
0 Comments
Leave a Reply. |