Shooting Lightning Out of the Sky (IMAGE) Optica Caption A picture of a femtosecond laser. The laser beam itself is invisible (800nm), but due to the formation of a plasma channel, the beam emits (visible) white light. Credit Jenya Papeer, Hebrew University, Israel Usage Restrictions None 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.