scandium nuclear clock (IMAGE) Texas A&M University Caption An artist's rendition of the scandium nuclear clock. Scientists used the X-ray pulses at the European XFEL to excite in the atomic nucleus of scandium — the sort of processes that can generate a clock signal at an unprecedented precision of one second in 300 billion years. Credit European XFEL/Helmholtz Institute Jena, Tobias Wüstefeld/Ralf Röhlsberger Usage Restrictions free use with credit License Original 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.