Fermion sound (IMAGE) Massachusetts Institute of Technology Caption MIT physicists have created a perfect fluid in the laboratory, and recorded the sound of that "perfect flow." The way that sound travels through this fluid can be used to calculate the sound, and "quantum friction," in neutron stars and other perfect fluids. Credit Image: Christine Daniloff, MIT Usage Restrictions Images are made available to non-commercial entities, press and the general public under a Creative Commons Attribution Non-Commercial No Derivatives license. You may not alter the images provided, other than to crop them to size. A credit line must be used when reproducing images; if one is not provided below. 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.