Optical Surface (IMAGE) Stanford University Caption This photo from 2014 shows the reflectivity of the mirror-like optical surface Fan, Raman and Goldstein have been researching, which allows for daytime radiative sky cooling by sending thermal energy into the sky while also blocking sunlight. The people in this photo (left to right) are Linxiano Zhu, Ph.D. '16, co-author of the 2014 paper, Fan and Raman. Credit Norbert?von?der?Groeben Usage Restrictions Image may only be used with appropriate caption or 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.