Several questions. 1. Do different observers (with the same knowledge) in different inertial frames agree on the number of states of some specific system? 2. The same question for the different accelerated frames; 3. The most difficult one Say, Alice observes some system X with N particles. She calculates the amount of information in that system. But Bob knows, that all particles in X are entangled with particles in system Y. Hence, for Bob system X contains less infromation, than for Alice. How it is possible? If the number of states is physical, how can it depend on something subjective, as the knowledge of some observer?