In the Copenhagen Interpretation, the observed state of a particle is random. In the Many Worlds interpretation, the all possible observed state of a particle are true, an the universe "splits". But isn't the version of the universe you are in after "splitting" also random, therefore not actually solving the problem of fundamental randomness?

  • 2
    $\begingroup$ Yes, and randomness isn't a "problem". $\endgroup$ – Abhimanyu Pallavi Sudhir Mar 12 at 23:10
  • $\begingroup$ But wouldn't "you" be in one of the the split realities? Eg. Why do "you" observe Schrodinger's cat dead while the other "you" observes it alive? Isn't it essentially random because the "you" who saw the cat dead could have seen it alive had he been the other "you". The chances of you before the observation becoming the "you" who sees it dead is essentially random. Basically, whether you actually experience A or B is random $\endgroup$ – user250486 Mar 13 at 5:25
  • $\begingroup$ Please keep in mind that randomness in quantum mechanics is weighted, the probabilities are weighted by the quantum mechanical equations. The death of the cat is weighted by the basic quantum mechanical decay probability. $\endgroup$ – anna v Mar 13 at 6:44
  • $\begingroup$ imo the many worlds interpretation is an example of the difference in basic thinking about reality , it is the ultimate platonic axiom "mathematics creates reality" . The other view is " reality is modeled by mathematics". $\endgroup$ – anna v Mar 13 at 6:47
  • $\begingroup$ @user250486 Yes. That's why I wrote "yes". What I'm saying is that randomness was never a problem to begin with. $\endgroup$ – Abhimanyu Pallavi Sudhir Mar 14 at 0:31

The randomness goes away because the observer splits along with the world. Most of the difficulty people have with Many Worlds comes from thinking that there is just one observer, but in fact an observer is a quantum mechanical object like everything else.

  • $\begingroup$ This is just some metaphysical comment that has nothing to do with physics. As far as physics is concerned, the individual observer's observations are random. $\endgroup$ – Abhimanyu Pallavi Sudhir Mar 14 at 0:33
  • $\begingroup$ My guess is that you and I are using the same words to mean different things. Surely you won't argue that in MW there is only one observer. $\endgroup$ – S. McGrew Mar 14 at 0:35
  • $\begingroup$ QM can have one observer or multiple observers, without changing the physics. This doesn't change when you add a metaphysical interpretation to it. $\endgroup$ – Abhimanyu Pallavi Sudhir Mar 14 at 9:56
  • $\begingroup$ Ok, then, what is the metaphysical component of my answer? $\endgroup$ – S. McGrew Mar 14 at 11:20
  • $\begingroup$ Substitute "measurement instrument" for "observer", and the metaphysical content is gone. Is it , in your opinion, a metaphysical idea that an observer and a measurement instrument are equivalent? $\endgroup$ – S. McGrew Mar 14 at 11:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.