Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Very naive doubt about MWI

  1. Sep 25, 2014 #1
    Hi to all. :)

    First of all i'm not cleary a physician, not even an amateur, only a writer and i hope that a so low level of knowledge don't offend anyone ^^' (my bad level and my broken english :look: )


    I have a question about the MWI. According with the most serious interpretation: we don’t have new universes that have been “create” every time, we already have “all” universe growing up in the same time, I have a doubt: how it can possible that two universe are “literally” the same universe except for one, single quantum event?

    I mean: our universe is the result of billions and billions and billions and billions (ecc) of elements that reactive each other in a billions and billions and billions and billions of different way for a very, very, very, very, very long time. How is possible that two universe product the same result?

    Now I try to see the problem in this way.

    In the Schrodinger experiment I put in the box George W. Bush (enough cat, poor animal… let him alone), with poison, electron and measurement tool. With spin positive I have a Bush live, with spin negative I have Bush not very well (I don’t wanna write “dead” cause I’m scared of the agency :look: ).

    Ok the experiment begin and in our universe the spine is positive, Bush is stile alive. This means that there is another universe with a Bush “not very well”?

    No, means that in another universe there is an electron with a negative spin, but in a different position or state, very probably there is no bush, no box, no poison and no earth.

    This way to see is compatible with the MWI? If not I return to first question, how is possible that so many variation are almost perfectly the same?

    Sorry for my broken English.
  2. jcsd
  3. Sep 26, 2014 #2


    Staff: Mentor

    No problem about the English.

    In MW the universe simply evolves - that's it.

    To understand further you need to become acquainted with decoherence:
    http://www.ipod.org.uk/reality/reality_decoherence.asp [Broken]

    As a result you end up with what's called an improper mixed state purely by quantum evolution. Each outcome is 'in' that state and the interpretation is they are separate worlds.

    Its a bit difficult to discuss the detail at the beginner level. However for completeness the following gives the detail:

    Last edited by a moderator: May 7, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Very naive doubt about MWI