A backjet of superfluid light

A laser pulse is like a drop of colored light that propagates undisturbed in a vacuum. Instead, when a drop of photons enters an optical microcavity designed to trap it and make it resonate with the vibrations of a thin semiconductor, a fluid mixture of light and matter is instantly created, which has the speed of photons and the interactions of electrons, and which, in part, reacts like the most familiar liquids to us, while in other respects it behaves according to the laws of quantum physics. Read more here.