Local stiffness and force chains. (IMAGE) Tokyo Metropolitan University Caption Distributions of harder regions (left) and force chains (right). Though they do correlate, force chains connect into string-like structures. Credit Tokyo Metropolitan University Usage Restrictions Credit must be given to the creator. License CC BY 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.