The Long Slow Death of the HBT Puzzle

Over the past 20 years two particle-correlations between identical pions have developed into a quantitative tool to test the space-time evolution of heavy-ion collisions. Surprisingly, correlations from RHIC failed to match expectations from hydrodynamic-based models, as the model-predicted source sizes were sometimes 50\% higher than was inferred from experiment. This failure became known as the HBT puzzle (Hanbury-Brown and Twiss were pioneers in the original technique). Since the success of these very models in predicting spectra and elliptic flow was central to the discovery of the ``perfect fluid,'' the failure of their HBT predictions was disquieting. In this talk, I will show how the discrepancy can be explained by the conspiracy of three effects: pre-equilibrium flow, using a stiffer equation of state and adding a modest viscosity. I will review the progress in finding a single description that reproduces the totality of soft bulk observables at RHIC.