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

Macro objects and superposition of states

  1. Jun 25, 2011 #1
    Is a living macro object, such as a cat or human being, in fact in a superposition of states?
    (I am thinking about for instance the multiple-universe idea)
  2. jcsd
  3. Jun 25, 2011 #2


    User Avatar
    Science Advisor

    At any given instant, there are probably a small number of individual systems at the molecular level in your body that are in quantum superpositions, however for the most part, people (or cats) have undergone decoherence, and are thus best described as being in mixed states. To learn about the distinction between superpositions and mixed states, try reading this: http://en.wikipedia.org/wiki/Mixed_state#Pure_and_mixed_states

    The upshot is that superpositions are coherent, i.e. there is a well-defined phase relationship between the components of the state. Decoherence can be thought of as the process of degradation of the coherence. A superposition that undergoes complete decoherence ends up as a mixed state.
  4. Jun 26, 2011 #3


    User Avatar

    Any state is unique.
    But some people do like destroy unique state in the superposition of other unique states of unliving abstract objects.
  5. Jun 26, 2011 #4


    User Avatar
    Science Advisor

    just realized that PF doesn't like links to wikipedia sections, so the link I posted above is broken (although it seemed to work fine when I previewed it) ... so check out the section on "Pure and Mixed States" at this link:http://en.wikipedia.org/wiki/Mixed_state
  6. Jun 26, 2011 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Looks fine to me. You just have to click on it rather than try to copy-paste it.
  7. Jun 26, 2011 #6


    User Avatar
    Science Advisor

    Yeah .. it works for me now too .. however just before I wrote that last post, I had clicked on a link to a wikipedia section in another thread, and I got the PF-version of the Not Found page. I thought "uh oh" and I came back here and tried my link from last night, and got the same message. However when I tried it again just now everything seems fine. Perhaps it is just some weird browser-PF-OS clash (I use FF 5.0 on Mac OS 10.5.8) that is exclusive to my machine.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Macro objects and superposition of states
  1. Superposition state (Replies: 3)

  2. Macro superposition (Replies: 68)