Oscillation time in wave function?

[Varon]

What are these oscillations in a coherent superposition?
A guy called Chalnoth stated in the Cosmology forum:

A large, complex object like a rock can't really be in a coherent superposition, let alone a galaxy.

Basically, the way we know about objects in coherent superpositions is through oscillation: we can observe the results of an object oscillating through, for instance, interference effects. But complex wavefunctions have oscillation times that tend to be very long, often much longer than the age of the universe.

And when your oscillation time is that long, there just isn't any way for the different components of the same wavefunction to obtain any information about one another. In fact, the different components of the wavefunction, when they are complex enough, interact so weakly with one another that they might as well be in different universes.

So anything as large as a galaxy in a superposition of states will behave exactly as if there was no superposition at all.

I don't know if he states this because of bias (he is a Many World interpretation believer). That's why I'm asking this here. He states dynamics can't occur in a superposition, meaning a galaxy can't evolve inside a superposition. What oscillation time is he talking about? What is the other words for it? Please correct if it there is any misrepresentation above. Thanks a lot.

 

[SpectraCat]

What are these oscillations in a coherent superposition?
A guy called Chalnoth stated in the Cosmology forum:



I don't know if he states this because of bias (he is a Many World interpretation believer). That's why I'm asking this here. He states dynamics can't occur in a superposition, meaning a galaxy can't evolve inside a superposition. What oscillation time is he talking about? What is the other words for it? Please correct if it there is any misrepresentation above. Thanks a lot.

I am not sure ... the use of complex is a bit ambiguous .. does he mean complicated? Or does he mean complex in the mathematical sense? I guess the former, in which case he may be talking about re-phasing time for a coherent wavepacket representing a superposition with a very large number of terms. I am not sure how relevant this is, because such systems would normally decohere long before the recurrence time is reached. I am also not sure what he means by the "there just isn't any way for the different components of the same wavefunction to obtain any information about one another". Typically one expands superpositions in an orthogonal basis, so there isn't any interaction between the different basis states. However, perhaps his point is that for sufficiently complicated systems, it is no longer possible to find a mutually orthogonal basis? Or maybe by "interact" he means "interfere"? It's hard to tell from the description you gave .. I will try to find the original thread and read more.

 

[Varon]

I am not sure ... the use of complex is a bit ambiguous .. does he mean complicated? Or does he mean complex in the mathematical sense? I guess the former, in which case he may be talking about re-phasing time for a coherent wavepacket representing a superposition with a very large number of terms. I am not sure how relevant this is, because such systems would normally decohere long before the recurrence time is reached. I am also not sure what he means by the "there just isn't any way for the different components of the same wavefunction to obtain any information about one another". Typically one expands superpositions in an orthogonal basis, so there isn't any interaction between the different basis states. However, perhaps his point is that for sufficiently complicated systems, it is no longer possible to find a mutually orthogonal basis? Or maybe by "interact" he means "interfere"? It's hard to tell from the description you gave .. I will try to find the original thread and read more.

He means the former, complex as complicated. Anyway. I'll post the original question. Try to answer it directly without attributing anything to him. I wrote originally.

Anyone familiar with both quantum mechanics and cosmology here. Say. How much dynamics can occur in the deterministic Schroedinger Equation in its evolution while it is in unitary state (before collapse)? For example. Is it possible for the Big Bang and evolution of stars to solar system and planets to occur while everything is inside a superposition (that doesn't involve Many Worlds but just as superposition of possibilities)? I'm trying to analyze the physicist Wigner who proposed that consciousness caused collapse of the wave function. Before life begins on earth. He seems to be saying that the universe is in a state of superposition. After life reaches a certain theshold. It finally collapsed the wave function of the Earth and the surrounding. Is this possible? Does the Schroedinger Equations allows for instance the evolution of a solar system while it is still unitary and before the wave function collapse? Or is it not possible?

If not possible. At least let me know why did this physicist Wigner propose it? Those in the QM forum are not familiar with cosmology so I have to post the question about Big bang in superposition here.

So can an entire galaxy evolve even if it is inside a superposition?

What do you think? Why not? Assume our universe is a close system. Let's say the universe starts as superposition, how many dynamics or complex interactions can occur while inside a superposition? Can it create stars and galaxies in such superposition?