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File:Silicon sphere for Avogadro project.jpg


English: A 1-kg single-crystal silicon sphere for the Avogadro Project is shown above in the hands of Master Optician Achim Leistner at the Australian Centre for Precision Optics (ACPO), which is part of Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO).
ACPO's spheres are among the roundest man-made objects in the world. If one of their Ø 93.6 mm spheres, which had an out-of-roundness of 35 nm, was scaled to the size of the Earth, its ‘continents’ would gradually rise only 2.4 meters above sea level.
Italiano: All' Australian Centre for Precision Optics (ACPO), parte del Commonwealth Scientific and Industrial Research Organisation (CSIRO) australiano, il Maestro ottico Achin Leistner tiene in mano una sfera da 1 kg per il Progetto avogadro costituita da un singolo cristallo di silicio.
Le sfere del centro ACPO sono gli oggetti più perfettamente rotondi al mondo mai prodotti dall'uomo. Se una delle sfere (dal diametro di 93.6 mm e aventi deviazione dalla sfericità di soli 35 nm) fosse ingrandita fino alla grandezza della Terra, le sue rugosità raggiungerebbero solamente i 2.4 metri dal livello del mare.
Date 11 January 2008
Source CSIRO
Author The Commonwealth Scientific and Industrial Research Organisation of Australia
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