Light is both a wave and a particle, and we know it for sure now Anna Bliokh/Getty Images The following is an extract from our  Lost in Space-Time  newsletter. Each month, we dive into fascinating ideas from around the universe. You can  sign up for  Lost in Space-Time  here . When physicist Clinton Davisson received the Nobel prize in 1937 for discovering that electrons , which had been considered to be particles, could sometimes unexpectedly behave like waves, he made a point of taking a jab at light. He said, “the perfect child of physics [had] been changed into a gnome with two heads”. It was already known to not be one or the other, but both wave-like and particle-like. Physicists used to think that being a particle and being a wave was mutually exclusive, yet here we had, in light and now also electrons, two examples contradicting that. Somewhat baffled, Davisson couldn’t help but reach for a grotesque metaphor.…