Decoherence Clarification

  • #276
241
43
One philosophical comment is in order. Here the states of the observer are the states of his brain. How the brain creates a mind is an unresolved question, but QM is probably not essential for that.
Fair enough. We'll leave that aside for now. But it seems clear to me that there should be a logical correlation between the the "brain state" of the observer and the state of the opened box being observed, regardless of the potential philosophical issues.
 
  • #277
Demystifier
Science Advisor
Insights Author
Gold Member
11,222
3,887
But it seems clear to me that there should be a logical correlation between the the "brain state" of the observer and the state of the opened box being observed
Of course, and that correlation is encoded in the last state above that I have written. Rougly speaking, the quantum state
|DECAY>|DEAD>|see dead cat>+|NOT DECAY>|ALIVE>|see alive cat>
can be translated into a logical expression
(DECAY and DEAD and see dead cat) OR (NOT DECAY and ALIVE and see alive cat).

But one should be careful, because the translation is not reversible. In the reverse direction, an expression like
A OR B
gets translated into
a|A>+b|B>
where a and b are unknown coefficients.
 
Last edited:
  • #278
241
43
After opening the box it is
|DECAY>|DEAD>|see dead cat>+|NOT DECAY>|ALIVE>|see alive cat>
This seems to be somewhat of a slippery slope for me. When considering the observer+cat+atom in the "post-observation" status, would this be thought of as a "full" system... meaning a "pure" system in superposition... if we imagine that the universe consists of only these physical elements.
 
  • #279
Demystifier
Science Advisor
Insights Author
Gold Member
11,222
3,887
This seems to be somewhat of a slippery slope for me. When considering the observer+cat+atom in the "post-observation" status, would this be thought of as a "full" system... meaning a "pure" system in superposition... if we imagine that the universe consists of only these physical elements.
Yes. If you are now going to ask why do we not see a superposition, I will tell you that the answer depends on the interpretation.
 
  • Like
Likes Feeble Wonk
  • #280
241
43
Yes. If you are now going to ask why do we not see a superposition, I will tell you that the answer depends on the interpretation.
[emoji39] You saw that coming a mile away. I've got some more thinking to do, and then I'd like to ask you more about how this relates to the SHV interpretation if that would be OK.
 
  • #281
Demystifier
Science Advisor
Insights Author
Gold Member
11,222
3,887
[emoji39] You saw that coming a mile away. I've got some more thinking to do, and then I'd like to ask you more about how this relates to the SHV interpretation if that would be OK.
Of course.
 

Related Threads on Decoherence Clarification

  • Last Post
Replies
4
Views
748
  • Last Post
Replies
4
Views
798
  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
2
Views
699
Replies
9
Views
969
  • Last Post
5
Replies
103
Views
17K
  • Last Post
3
Replies
60
Views
3K
  • Last Post
Replies
12
Views
3K
  • Last Post
Replies
18
Views
3K
Top