Macro objects and superposition of states

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Discussion Overview

The discussion revolves around the concept of whether living macro objects, such as cats or humans, exist in a superposition of states, particularly in the context of the multiple-universe idea. It explores the implications of quantum mechanics on living systems, including the effects of decoherence and mixed states.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that while individual systems at the molecular level may be in quantum superpositions, living macro objects have generally undergone decoherence, making them better described as being in mixed states.
  • Others argue that any state is unique and suggest that there is a tendency to overlook the uniqueness of states in superpositions of other unique states.
  • Participants discuss the distinction between coherent superpositions and mixed states, noting that decoherence leads to a degradation of coherence.
  • There are mentions of issues with sharing links to external resources, specifically Wikipedia, which some participants experienced inconsistently.

Areas of Agreement / Disagreement

Participants express differing views on the nature of superpositions in living macro objects, with some asserting that decoherence predominates, while others emphasize the uniqueness of states. The discussion remains unresolved regarding the implications of these perspectives.

Contextual Notes

There are limitations in the discussion regarding the definitions of superpositions and mixed states, as well as the conditions under which decoherence occurs. These aspects are not fully explored or agreed upon.

entropy1
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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)
 
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entropy1 said:
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)

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.
 
entropy1 said:
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)
Any state is unique.
But some people do like destroy unique state in the superposition of other unique states of unliving abstract objects.
 
SpectraCat said:
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.

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
 
SpectraCat said:
just realized that PF doesn't like links to wikipedia sections,
Looks fine to me. You just have to click on it rather than try to copy-paste it.
 
Hurkyl said:
Looks fine to me. You just have to click on it rather than try to copy-paste it.

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.
 

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