Visitors are Calmly Waiting (IMAGE) Ruhr-University Bochum Caption Visitors are calmly waiting to be let in, in the same way as they do at a supermarket check-out: barriers help avoid a crush of people in bottleneck areas. Credit Forschungszentrum Jülich, Maik Boltes 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.