The recent availability of complete three dimensional samples of galaxies and clusters permits a direct study of their spatial properties. We present a brief review of galaxy correlations based on the methods modern statistical Physics. These methods which able to identify self-similar and non-analytical prop ties, allow us to test the usual homogeneity assumption of luminous matter distribution. We conclude that both the three dimensional prop ties, and the angular log <I>N </I>- log S relation, point out the fact that the distribution of galaxies and clusters fractal with <i>D</i> ≈ 2 up to the deepest scale probed luminous matter (≈≥ <I>1000h<sup>-1</sup> Mpc).</I> This result has important implications for the theoretical framework that should be adopted.