A Silicon kilogram (IMAGE) American Institute of Physics Caption The number of atoms in this silicon sphere is known given or taken 20 atoms each 10^9. The atom distance was measured by the X-ray interferometer on the left. Credit Enrico Massa and Carlo Sasso Usage Restrictions This image may be used only with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.