Many Worlds or Many Problems?

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  • #201
Hurkyl
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Even wavefunction taken as all there is doesn't yield MWI, so, yeah...
Of course not; there is also the hypothesis that the wavefunction only evolves according to Schrödinger's equation.*, as opposed to the combination of Schrödinger's equation and collapse.

I suppose MWI doesn't become interesting, though, unless you consider the additional hypothesis that quantum mechanics remains valid on larger scales -- e.g. that the decoherence seen in measurement is a result of quantum thermodynamics.


If you want to keep insisting that MWI is equivalent to trying to insist that all probability distributions are uniform, that's your problem not mine.


* or whatever the appropriate notion of state and unitary evolution is needed for the particular variant of QM being considered
 
  • #202
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"Quantum universe" remains in its superposition state and it is not the universe you perceive as such.
Yup!
 
  • #203
I just wonder if those who consider MWI to be wrong and that consciousness plays an integral part in determining a result, whether a belief or expectational bias on behalf of an observer can also have a bearing on the probabilistic outcome of a collapse in wave function?
 
  • #204
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I just wonder if those who consider MWI to be wrong and that consciousness plays an integral part in determining a result, whether a belief or expectational bias on behalf of an observer can also have a bearing on the probabilistic outcome of a collapse in wave function?
Very very few of those who reject mwi (majority of physicists) believe in such nonsense that consciousness has ANYTHING to do with anything.
 
  • #205
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If MWI is wrong, it means one of:
  • Some aspect of quantum mechanics is wrong
  • Experimentally observed statistics in subsystems are not the result of unitary evolution in larger systems
  • There are other components to physical state beyond the wave-function which contribute to observations
  • Some other mode of failure I didn't think of

The difference between physical state collapsing to a single outcome versus remaining a statistical mixture is not a physical difference -- no observation can distinguish between the two possibilities.

Consciousness has pretty much nothing to do with any of the above. Anything that talks about consciousness is a separate thing layered on top of the basics.
Hurkyl, from 1 to 10, how true do you think is MWI? Is it 10? or 5?
 
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Hurkyl doesn't even understand basic QM.
He thinks that if MWI is wrong it means QM is wrong...
He always claimed there are no Born Rule problem with MWI, yet he hasn't given any source to this claim.
 
  • #207
Very very few of those who reject mwi (majority of physicists) believe in such nonsense that consciousness has ANYTHING to do with anything.
Well, perhaps with the exception of the observation itself?
 
  • #208
Hurkyl
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Hurkyl, from 1 to 10, how true do you think is MWI? Is it 10? or 5?
You mean as compared to other interpretations? I don't think the question is meaningful.

Are you referring instead to the hypothesis that quantum thermodynamics can accurately treat larger systems? My impression is that physicists are fairly confident in that.

Are you referring instead to the hypothesis that quantum thermodynamics can accurately treat truly macroscopic systems in which gravity is negligible (such as a cat in a poison booth controlled by the decay of an atom)? It seems reasonable to be optimistic, although it seems a lot of theoretical developments have to be made to work out the mathematics. More importantly, all of the reasons I have ever heard to be severely pessimistic about it have been discredited.


The real question about interpretation is utility. As quantum mechanics is used to treat larger and larger systems, I don't see how one could possibly avoid thinking of things in a MWI-like fashion without deliberately avoiding to try and form any mental concept of the behavior a wave-function evolving unitarily.
 
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  • #209
Hurkyl, from 1 to 10, how true do you think is MWI? Is it 10? or 5?
Excuse me for interfering, but from my perspective it's the key question to address MWI appeal:

First of all, in my opinion the theory cannot be "correct" or "right"; it may possess more or less predictive power, from this perspective MWI does no prove definitively its superiority (so far). The Wrong/Right paradigm can be only applied if we assume that there is the Grand Design which science can reveal - it's apparently a religious assumption. The major appeal of MWI, in my opinion - MWI just makes more sense for some who is prone to look for more general explanations.

Stefan
 
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  • #210
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Suppose MWI is correct, does that mean ALL possible realities exist physically? If the answer is yes then that means there exists a physical reality in which there is a law that prohibits the existence of ALL OTHER REALITIES! So you see MWI contradicts ITSELF. Guess what, we exist in THAT reality (the one that prohibits ALL OTHERS) MWI is incorrect. To give you an example of how absurd MWI is...are you seriously suggesting that there exists a physical reality in which i have 23 heads, 7 arms, 19 legs, a spinal column made of fractals, and 53 oragutans are having sex with the girl next door 24/7? The ABSURDITIES i can list here are finite, but the absurdities made possible by MWI must NECESSARILLY be infinite (play on a quote by Wittgenstien)

And now for The Granfather Paradox. This one is AGAINST time travel. Suppose you travel back in time and kill your grandfather BEFORE your father is CONCIEVED. Where does that leave you? If your father was never here how can you be here able to go back etc...

Now my idea...Time travel should be possible so that your grandfather can travel FORWARD in time and kill you just BEFORE you go back in time to kill him. This one is in favor of time travel. I call this MY GRANDFATHERS REVENGE THEORY. This theory is in reply to Steven Hawkins theory that the past must be made safe for historians. My theory makes the future safe for grandfathers.
 

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