Gibble Quantum Scattering 1 (of 2) (IMAGE) Penn State Caption Schematic of the Experiment. We collide a clock atom with atoms in another state (labeled |4, 4>). When the clock atoms collide, they experience a discrete jump, which is the difference of two s-wave phase shifts. The s-wave phase shifts can be measured with atomic-clock accuracy and give precise information about the atom-atom interactions. Credit Kurt Gibble, Penn State Usage Restrictions none 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.