Exhaled material moves in a jet (IMAGE) Princeton University, Engineering School Caption To study the flow of exhaled material, researchers filmed the movement of a mist of tiny droplets illuminated by a laser sheet in front of a person speaking several different phrases adjacent to the sheet. Photo composition by Princeton University. Credit Princeton University 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.