 The basis for the correspondence between the quantum state (the wave function) of the Universe and our experience is the description that physicists give in the framework of standard quantum theory for objects composed of elementary particles. Elementary particles of the same kind are identical (see the elaborate discussion in the entry on  identity and individuality in quantum theory).  The essence of an object is the (massively entangled) quantum state of its particles and not the particles themselves. One quantum state of a set of elementary particles might be a cat and another state of the same particles might be a small table. An object is a spatial pattern of such a quantum state. Clearly, we cannot now write down an exact wave function of a cat. We know, to a reasonable approximation, the wave function of the elementary particles that constitute a nucleon. The wave function of the electrons and the nucleons that together make up an atom is known with even better precision. The wave functions of molecules (i.e. the wave functions of the ions and electrons out of which molecules are built) are well studied. A lot is known about biological cells, and physicists are making progress in the quantum representation of biological systems Cao et. al 2020. Out of cells we construct various tissues and then the whole body of a cat or a table. So, let us denote the quantum state of a macroscopic object constructed in this way \(\ket{\Psi}_\object.\)