Quantum phenomena seem to blur the distinction between matter and information, and objectivity and subjectivity. A quantum particle cannot be observed directly and needs to be 'observed' in a suitably designed measurement experiment. Even in such an experiment, what we actually observe (by means of senses) is the measuring device, which is said to be ‘classical’. The position and other 'observable' properties of a quantum particle (QP) are only inferred from the devices’ readings. Quantum Mechanics tells us that a QP is a packet of de Broglie's phase waves, each of which carries no energy and goes faster than light. Clearly, the phase wave is a mathematical abstraction, an idea in physicists' minds; it cannot be observed for example, like light, or heard like a wave of an oscillating string. However, the phase wave’s wavelength can be measured in a suitably designed experiment. So, one may call the de Broglie phase wave as a piece of ‘objective information’! Since classical matter, i.e., matter which is observable directly by senses is supposed to be made of numerous QPs also, it seems that all matter is made of ‘objective information’, i.e., information, which is not observable directly but some of whose properties can be measured and verified in some way and agreed upon by a group of people. Considering the brain to be a quantum system, we will explain why a sensory experience is both objective and subjective at the same time whereas other conscious experiences such as those of emotions and judgments are subjective but not objective. For this purpose, we note the neuroscience finding that it is necessary and sufficient that one’s brain (a quantum system) builds a neural record which is a faithful representation of the sensory input it receives from the outside world, for one to have the corresponding conscious sensory experience.

Matter and Information, Subjectivity, Objectivity, Intersubjective agreement, De Broglie Phase Wave, ‘Objective’ information