Recent searching of the light from the quasars indicate lack of the quantum fluctuation of the spacetime. http://arxiv.org/PS_cache/arxiv/pdf/1108/1108.6005v1.pdf Does it mean the lack of quantum foam rules out the discretness of the spacetime too ? How to explain Casimir effect and gravitational redshift then ? Are there two notions of the vacuum in the science : 1. Energetic, material vacuum full of fluctuating virtual particles ? 2. Mathematical vacuum made of the relation between encoded information ? The conservation of the quantum state at long distance according to the above article indicate the conservation of the quantum information and quantum superposition. The mathematical holographic universe is made of the quantum information relations which are not necessarilly the vacuum fluctuations. The holographic universe is created due to conservation of the quantum information first of all. How the change of the polarization of the light is possible if there is a quantum superposition and conservation of the information ?