Very interesting observation. In the way quantum mechanics is used in practice, there is always a microscopic quantum system (like an electron, or a set of atoms) and a macroscopic classical world of measurement apparatuses and observers. Of course, this macroscopic classical world is supposed to emerge from a microscopic quantum description. Concepts like the wavefunction of the universe, associated with the many worlds interpretation, don't directly describe the classical world we see around us. Attempts to recover the classical world (and also things like the collapse of the wavefunction and the Born rule) from the universal wavefunction always have to assume the existence of a type of observer who cannot be conscious of the whole many-worlds superposition, but only of "one world at a time". Think of the Schrodinger cat experiment: when the observer looks at the cat, and gets entangled with it, the thing that causes the (apparent?) collapse of the wavefunction is the fact that the observer cannot be conscious of his own superposition, so (the story goes) the observer and the whole world around him splits into two, in some sense. In any case, whether you lean more towards a collapse view or a many-worlds view, it seems that the notion of classicality comes from the properties of the observer's consciousness. Of course, there is something awfully self-referential here as well, because the conscious state should depend on the physical state of the brain, which in turn depends on the classical world.
It's very difficult to understand for me. If one consciousness can be expressed through one brain, we might see something new from that. It may be impossible to realize a quantum computer. But people who are researching it would like to make it possible.
Very interesting observation. In the way quantum mechanics is used in practice, there is always a microscopic quantum system (like an electron, or a set of atoms) and a macroscopic classical world of measurement apparatuses and observers. Of course, this macroscopic classical world is supposed to emerge from a microscopic quantum description.
Concepts like the wavefunction of the universe, associated with the many worlds interpretation, don't directly describe the classical world we see around us. Attempts to recover the classical world (and also things like the collapse of the wavefunction and the Born rule) from the universal wavefunction always have to assume the existence of a type of observer who cannot be conscious of the whole many-worlds superposition, but only of "one world at a time". Think of the Schrodinger cat experiment: when the observer looks at the cat, and gets entangled with it, the thing that causes the (apparent?) collapse of the wavefunction is the fact that the observer cannot be conscious of his own superposition, so (the story goes) the observer and the whole world around him splits into two, in some sense.
In any case, whether you lean more towards a collapse view or a many-worlds view, it seems that the notion of classicality comes from the properties of the observer's consciousness. Of course, there is something awfully self-referential here as well, because the conscious state should depend on the physical state of the brain, which in turn depends on the classical world.
It's very difficult to understand for me.
If one consciousness can be expressed through one brain, we might see something new from that. It may be impossible to realize a quantum computer. But people who are researching it would like to make it possible.