Step 1: Initialize fireball with Temperature T Step 2: Evolve fireball in space, it cools down such that the total energy of the fireball is constant in time Step 3: In each evolution, photons are created from a random distribution following T^n*exp(-p/T) (we do not consider blueshifted photons for now) Step 4: Be happy and collect the photons Step 10000: Build realistic BE correlations into this model