Sambamurti Lecture

The hottest matter ever created exists for only a tiny fraction of a second, yet it behaves like an almost perfect liquid. This remarkable state of matter, known as the quark—gluon plasma, filled the universe just millionths of a second after the Big Bang and is now recreated by smashing together atomic nuclei at nearly the speed of light with particle colliders, like the Relativistic Heavy Ion Collider (right here at BNL). For many years, most believed that such a fluid could only emerge in the largest and most violent nuclear collisions where thousands of particles are created. Recent discoveries, however, have challenged this picture, suggesting that even much smaller systems, which produce tens of particles, may exhibit the same collective fluid-like behavior. In this lecture, I will describe an unexpected new frontier: using a single particle of light, a photon, to create and study one of the smallest droplets of this hottest fluid ever observed. In addition, BNL is constructing the Electron-Ion Collider which is a factory for photon-ion collisions which may exhibit fluid-like behavior; I will discuss the possibilities. Along the way, I will show how modern particle detectors, precision measurements, and international collaborations allow us to explore matter under the most extreme conditions found anywhere in the universe, bringing us closer to understanding how the fundamental building blocks of nature behave.