Researcher Observations (IMAGE) Princeton University, Engineering School Caption The researchers send bubbles through a tank containing a thin surface of oil above a water bath to make their observations. Credit Photos by Frank Wojciechowski for the Office of Engineering Communications. Usage Restrictions Non-Commercial Use 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.