Information break of time symmetry in the macroscopic limit

The evident contrast between the time symmetry of fundamental microscopic laws and the time asymmetry of macroscopic processes is a challenging physical problem. The observation of unitary evolution of a general physical system by an idealized observer whose recording and processing information is time neutral is studied in a full information context. In the macroscopic limit, a contradiction between observations and predictions done at different times appears. It implies that the observer cannot read records performed at times when the entropy of the system is larger.