Symmetry of Many-Worlds?

[nomadreid]

The Many-Worlds interpretation tells us where the information “goes” at a measurement. Does it also tell us where the information “comes from” afterward to create the new undetermined state? If it is symmetrical, then does that mean that a measurement is the result of confluence or interference of worlds, which would be the symmetry of the splitting up into many worlds? That is, would a measurement be a node in a network?

[haael]

You are right, Many-Worlds is symmetrical in that matter. But the flow of the information is different from what you are writing here. After a measurement, fresh information appears; when a superposition forms, information disappears.

[nomadreid]

Thank you, haael. But I thought that one of the central tenets of quantum mechanics was the conservation of information.:confused:

[Demystifier]

Thank you, haael. But I thought that one of the central tenets of quantum mechanics was the conservation of information.:confused:
One should distinguish information encoded in the total wave function of the universe/multiverse (which is conserved) from information available to a local macroscopic observer (which may not be conserved).

[nomadreid]

One should distinguish information encoded in the total wave function of the universe/multiverse (which is conserved) from information available to a local macroscopic observer (which may not be conserved).

Thank you, Demystifier. I would be grateful if I could check to see if I understand the distinction. Is the following formulation more or less correct?

In the Many-Worlds Theory the universal wave function is taken over the collection of worlds. An apparent local "collapse" is due to a shift in the observer's frame of reference inside this collection of worlds. In this case, then, information is destroyed or created locally only because of the shift of this frame of reference, so that the wave function "splitting" into many different worlds be only from the point of view of the local observer. From the point of view of the universal wave function, there is no "splitting".

Thanks in advance for any corrections to this.

[Demystifier]

In the Many-Worlds Theory the universal wave function is taken over the collection of worlds. An apparent local "collapse" is due to a shift in the observer's frame of reference inside this collection of worlds. In this case, then, information is destroyed or created locally only because of the shift of this frame of reference, so that the wave function "splitting" into many different worlds be only from the point of view of the local observer. From the point of view of the universal wave function, there is no "splitting".

I don't know what exactly do you mean by "observer's frame of reference inside this collection of worlds", but the spirit of your words above seems essentially correct.

[nomadreid]

Thanks, Demystifier. Yes, I admit that "observer's frame of reference inside this collection of worlds" was a bit of hand-waving for the simple reason that this is the next thing that I am trying to make precise and to understand. I suppose there is another world in which another nomadreid wrote you a more precise description. Too bad that these worlds don't interact......