Gravitational waves (IMAGE) University of Helsinki Caption Colliding spherical pressure waves from a phase transition at around 10 picoseconds after the Big Bang would generate gravitational waves observable by LISA Credit David Weir Usage Restrictions Credit: David Weir License Original 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.