Urine Stream Water Surface Impact (IMAGE) American Institute of Physics Caption This shows the dramatic water entry of a simulated male urine stream impacting a water surface and opening a large, interesting cavity with multiple ridges. Each droplet forms a small cavity wherein the next droplet can pass and form an additional cavity creating a chain of small cavity structures. Credit BYU/Randy Hurd and Tadd Truscott 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.