  At the Relativistic Heavy Ion Collider (RHIC), key insights into the bulk
properties of the hot and dense partonic matter arise from the study of
azimuthal anisotropy (v_2) of the produced particles. The v_2 values indicate
that the matter undergoes rapid thermalization and behaves hydrodynamically at
low p_T. Furthermore, the quark scaling of v_2 for different particle species
suggests that thermalization occurs at the quark level and that v_2 is the same
for all quark flavors. Recently, higher order harmonic measurements (v_3, v_4)
have shown the potential for insights into the medium's initial geometry and
fluctuations. This proceeding discusses some of the PHENIX Collaboration's
latest flow results and their implications.
