  Heavy ion collisions at RHIC are well described by the (nearly ideal)
hydrodynamics for average events. In the present paper we study initial state
fluctuations appearing on event-by-event basis, and the propagation of
perturbations induced by them. We found that (i) fluctuations of several lowest
harmonics have comparable magnitudes, (ii) that at least all odd harmonics are
correlated in phase, (iii) thus indicating the local nature of fluctuations.
  We argue that such local perturbation should be the source of the "Tiny
Bang", a pulse of sound propagating from it. We identify its two fundamental
scales as (i) the
  "sound horizon" (analogous to the absolute ruler in cosmic microwave
background and galaxy distribution) and (ii) the "viscous horizon", separating
damped and undamped harmonics.
  We then qualitatively describe how one can determine them from the data, and
thus determine two fundamental parameters of the matter, the (average) {\em
speed of sound} and {\em viscosity}.
