Weighing Neutrinos (image) American Physical Society Caption These images represent numerical simulations comparing of the density of matter in a slice of the Universe with and without massive neutrinos. The two simulations started from the same initial conditions, with either massless neutrinos (left) or neutrinos with masses of 1.9 eV (right). In the massive neutrino case, matter is spread over a larger number of structures. Credit Shankar Agarwal and Hume Feldman, University of Kansas Usage Restrictions None 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.